EVOLUTION-MANAGER
Edit File: classOGRUnionLayer.html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/> <meta http-equiv="X-UA-Compatible" content="IE=9"/> <meta name="generator" content="Doxygen 1.8.5"/> <title>OGR: OGRUnionLayer Class Reference</title> <link href="tabs.css" rel="stylesheet" type="text/css"/> <script type="text/javascript" src="jquery.js"></script> <script type="text/javascript" src="dynsections.js"></script> <link href="doxygen.css" rel="stylesheet" type="text/css" /> </head> <body> <div id="top"><!-- do not remove this div, it is closed by doxygen! --> <div id="titlearea"> <table cellspacing="0" cellpadding="0"> <tbody> <tr style="height: 56px;"> <td style="padding-left: 0.5em;"> <div id="projectname">OGR </div> </td> </tr> </tbody> </table> </div> <!-- end header part --> <!-- Generated by Doxygen 1.8.5 --> <div id="navrow1" class="tabs"> <ul class="tablist"> <li><a href="index.html"><span>Main Page</span></a></li> <li><a href="pages.html"><span>Related Pages</span></a></li> <li class="current"><a href="annotated.html"><span>Classes</span></a></li> <li><a href="files.html"><span>Files</span></a></li> </ul> </div> <div id="navrow2" class="tabs2"> <ul class="tablist"> <li><a href="annotated.html"><span>Class List</span></a></li> <li><a href="hierarchy.html"><span>Class Hierarchy</span></a></li> <li><a href="functions.html"><span>Class Members</span></a></li> </ul> </div> </div><!-- top --> <div class="header"> <div class="summary"> <a href="#pub-methods">Public Member Functions</a> | <a href="classOGRUnionLayer-members.html">List of all members</a> </div> <div class="headertitle"> <div class="title">OGRUnionLayer Class Reference</div> </div> </div><!--header--> <div class="contents"> <div class="dynheader"> Inheritance diagram for OGRUnionLayer:</div> <div class="dyncontent"> <div class="center"> <img src="classOGRUnionLayer.png" usemap="#OGRUnionLayer_map" alt=""/> <map id="OGRUnionLayer_map" name="OGRUnionLayer_map"> <area href="classOGRLayer.html" alt="OGRLayer" shape="rect" coords="0,0,104,24"/> </map> </div></div> <table class="memberdecls"> <tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="pub-methods"></a> Public Member Functions</h2></td></tr> <tr class="memitem:a530eaa40528ad609ae506336103fbedf"><td class="memItemLeft" align="right" valign="top">virtual const char * </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a530eaa40528ad609ae506336103fbedf">GetName</a> ()</td></tr> <tr class="memdesc:a530eaa40528ad609ae506336103fbedf"><td class="mdescLeft"> </td><td class="mdescRight">Return the layer name. <a href="#a530eaa40528ad609ae506336103fbedf">More...</a><br/></td></tr> <tr class="separator:a530eaa40528ad609ae506336103fbedf"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a11d7365a8f7264b0cc0bfc3cd371aac7"><td class="memItemLeft" align="right" valign="top">virtual <a class="el" href="ogr__core_8h.html#a800236a0d460ef66e687b7b65610f12a">OGRwkbGeometryType</a> </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a11d7365a8f7264b0cc0bfc3cd371aac7">GetGeomType</a> ()</td></tr> <tr class="memdesc:a11d7365a8f7264b0cc0bfc3cd371aac7"><td class="mdescLeft"> </td><td class="mdescRight">Return the layer geometry type. <a href="#a11d7365a8f7264b0cc0bfc3cd371aac7">More...</a><br/></td></tr> <tr class="separator:a11d7365a8f7264b0cc0bfc3cd371aac7"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a20c1d59b04f816722d0d6f865f079273"><td class="memItemLeft" align="right" valign="top">virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a20c1d59b04f816722d0d6f865f079273">ResetReading</a> ()</td></tr> <tr class="memdesc:a20c1d59b04f816722d0d6f865f079273"><td class="mdescLeft"> </td><td class="mdescRight">Reset feature reading to start on the first feature. <a href="#a20c1d59b04f816722d0d6f865f079273">More...</a><br/></td></tr> <tr class="separator:a20c1d59b04f816722d0d6f865f079273"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a1ff231230bc51b63952c49fbf565d2b8"><td class="memItemLeft" align="right" valign="top">virtual <a class="el" href="classOGRFeature.html">OGRFeature</a> * </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a1ff231230bc51b63952c49fbf565d2b8">GetNextFeature</a> ()</td></tr> <tr class="memdesc:a1ff231230bc51b63952c49fbf565d2b8"><td class="mdescLeft"> </td><td class="mdescRight">Fetch the next available feature from this layer. <a href="#a1ff231230bc51b63952c49fbf565d2b8">More...</a><br/></td></tr> <tr class="separator:a1ff231230bc51b63952c49fbf565d2b8"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a58427b11107fee76162055092e2364d2"><td class="memItemLeft" align="right" valign="top">virtual <a class="el" href="classOGRFeature.html">OGRFeature</a> * </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a58427b11107fee76162055092e2364d2">GetFeature</a> (long nFeatureId)</td></tr> <tr class="memdesc:a58427b11107fee76162055092e2364d2"><td class="mdescLeft"> </td><td class="mdescRight">Fetch a feature by its identifier. <a href="#a58427b11107fee76162055092e2364d2">More...</a><br/></td></tr> <tr class="separator:a58427b11107fee76162055092e2364d2"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a094a2f13809f0b2eaabbc572ddfc19ed"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a094a2f13809f0b2eaabbc572ddfc19ed">CreateFeature</a> (<a class="el" href="classOGRFeature.html">OGRFeature</a> *poFeature)</td></tr> <tr class="memdesc:a094a2f13809f0b2eaabbc572ddfc19ed"><td class="mdescLeft"> </td><td class="mdescRight">Create and write a new feature within a layer. <a href="#a094a2f13809f0b2eaabbc572ddfc19ed">More...</a><br/></td></tr> <tr class="separator:a094a2f13809f0b2eaabbc572ddfc19ed"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:ab44d7c6a95d8d6a73f906f60760c0c56"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#ab44d7c6a95d8d6a73f906f60760c0c56">SetFeature</a> (<a class="el" href="classOGRFeature.html">OGRFeature</a> *poFeature)</td></tr> <tr class="memdesc:ab44d7c6a95d8d6a73f906f60760c0c56"><td class="mdescLeft"> </td><td class="mdescRight">Rewrite an existing feature. <a href="#ab44d7c6a95d8d6a73f906f60760c0c56">More...</a><br/></td></tr> <tr class="separator:ab44d7c6a95d8d6a73f906f60760c0c56"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a4c680d7e5c02454ea7361f341d6d54e9"><td class="memItemLeft" align="right" valign="top">virtual <a class="el" href="classOGRFeatureDefn.html">OGRFeatureDefn</a> * </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9">GetLayerDefn</a> ()</td></tr> <tr class="memdesc:a4c680d7e5c02454ea7361f341d6d54e9"><td class="mdescLeft"> </td><td class="mdescRight">Fetch the schema information for this layer. <a href="#a4c680d7e5c02454ea7361f341d6d54e9">More...</a><br/></td></tr> <tr class="separator:a4c680d7e5c02454ea7361f341d6d54e9"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a8223e23c723151ef11fba997ab4fc605"><td class="memItemLeft" align="right" valign="top">virtual <a class="el" href="classOGRSpatialReference.html">OGRSpatialReference</a> * </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a8223e23c723151ef11fba997ab4fc605">GetSpatialRef</a> ()</td></tr> <tr class="memdesc:a8223e23c723151ef11fba997ab4fc605"><td class="mdescLeft"> </td><td class="mdescRight">Fetch the spatial reference system for this layer. <a href="#a8223e23c723151ef11fba997ab4fc605">More...</a><br/></td></tr> <tr class="separator:a8223e23c723151ef11fba997ab4fc605"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a6f9c4f51181cb7db75b08a6b81182e67"><td class="memItemLeft" align="right" valign="top">virtual int </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a6f9c4f51181cb7db75b08a6b81182e67">GetFeatureCount</a> (int)</td></tr> <tr class="memdesc:a6f9c4f51181cb7db75b08a6b81182e67"><td class="mdescLeft"> </td><td class="mdescRight">Fetch the feature count in this layer. <a href="#a6f9c4f51181cb7db75b08a6b81182e67">More...</a><br/></td></tr> <tr class="separator:a6f9c4f51181cb7db75b08a6b81182e67"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a2231dba322c7cfbc5914e2201d27c610"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a2231dba322c7cfbc5914e2201d27c610">SetAttributeFilter</a> (const char *)</td></tr> <tr class="memdesc:a2231dba322c7cfbc5914e2201d27c610"><td class="mdescLeft"> </td><td class="mdescRight">Set a new attribute query. <a href="#a2231dba322c7cfbc5914e2201d27c610">More...</a><br/></td></tr> <tr class="separator:a2231dba322c7cfbc5914e2201d27c610"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a6ba10280ddeda91a8ec0efc29e9ef7d6"><td class="memItemLeft" align="right" valign="top">virtual int </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a6ba10280ddeda91a8ec0efc29e9ef7d6">TestCapability</a> (const char *)</td></tr> <tr class="memdesc:a6ba10280ddeda91a8ec0efc29e9ef7d6"><td class="mdescLeft"> </td><td class="mdescRight">Test if this layer supported the named capability. <a href="#a6ba10280ddeda91a8ec0efc29e9ef7d6">More...</a><br/></td></tr> <tr class="separator:a6ba10280ddeda91a8ec0efc29e9ef7d6"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a36e1634fb7f68fae343179a6007960c4"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a36e1634fb7f68fae343179a6007960c4">GetExtent</a> (int iGeomField, <a class="el" href="classOGREnvelope.html">OGREnvelope</a> *psExtent, int bForce=TRUE)</td></tr> <tr class="memdesc:a36e1634fb7f68fae343179a6007960c4"><td class="mdescLeft"> </td><td class="mdescRight">Fetch the extent of this layer, on the specified geometry field. <a href="#a36e1634fb7f68fae343179a6007960c4">More...</a><br/></td></tr> <tr class="separator:a36e1634fb7f68fae343179a6007960c4"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a3c80b4bddf35c4951b307929fa17228e"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a3c80b4bddf35c4951b307929fa17228e">GetExtent</a> (<a class="el" href="classOGREnvelope.html">OGREnvelope</a> *psExtent, int bForce)</td></tr> <tr class="memdesc:a3c80b4bddf35c4951b307929fa17228e"><td class="mdescLeft"> </td><td class="mdescRight">Fetch the extent of this layer. <a href="#a3c80b4bddf35c4951b307929fa17228e">More...</a><br/></td></tr> <tr class="separator:a3c80b4bddf35c4951b307929fa17228e"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a194555741a74ee0e61c92875683cce7f"><td class="memItemLeft" align="right" valign="top">virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a194555741a74ee0e61c92875683cce7f">SetSpatialFilter</a> (<a class="el" href="classOGRGeometry.html">OGRGeometry</a> *poGeomIn)</td></tr> <tr class="memdesc:a194555741a74ee0e61c92875683cce7f"><td class="mdescLeft"> </td><td class="mdescRight">Set a new spatial filter. <a href="#a194555741a74ee0e61c92875683cce7f">More...</a><br/></td></tr> <tr class="separator:a194555741a74ee0e61c92875683cce7f"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a2ece59929973a6f19a95443e45ffccad"><td class="memItemLeft" align="right" valign="top">virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a2ece59929973a6f19a95443e45ffccad">SetSpatialFilter</a> (int iGeomField, <a class="el" href="classOGRGeometry.html">OGRGeometry</a> *)</td></tr> <tr class="memdesc:a2ece59929973a6f19a95443e45ffccad"><td class="mdescLeft"> </td><td class="mdescRight">Set a new spatial filter. <a href="#a2ece59929973a6f19a95443e45ffccad">More...</a><br/></td></tr> <tr class="separator:a2ece59929973a6f19a95443e45ffccad"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a81737b724f0c7c0f81d593cec662bb08"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a81737b724f0c7c0f81d593cec662bb08">SetIgnoredFields</a> (const char **papszFields)</td></tr> <tr class="memdesc:a81737b724f0c7c0f81d593cec662bb08"><td class="mdescLeft"> </td><td class="mdescRight">Set which fields can be omitted when retrieving features from the layer. <a href="#a81737b724f0c7c0f81d593cec662bb08">More...</a><br/></td></tr> <tr class="separator:a81737b724f0c7c0f81d593cec662bb08"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a2504c28d8bb046a55c198dbdc58e99bb"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRUnionLayer.html#a2504c28d8bb046a55c198dbdc58e99bb">SyncToDisk</a> ()</td></tr> <tr class="memdesc:a2504c28d8bb046a55c198dbdc58e99bb"><td class="mdescLeft"> </td><td class="mdescRight">Flush pending changes to disk. <a href="#a2504c28d8bb046a55c198dbdc58e99bb">More...</a><br/></td></tr> <tr class="separator:a2504c28d8bb046a55c198dbdc58e99bb"><td class="memSeparator" colspan="2"> </td></tr> <tr class="inherit_header pub_methods_classOGRLayer"><td colspan="2" onclick="javascript:toggleInherit('pub_methods_classOGRLayer')"><img src="closed.png" alt="-"/> Public Member Functions inherited from <a class="el" href="classOGRLayer.html">OGRLayer</a></td></tr> <tr class="memitem:adc3735e444204d46f517eec251712f4d inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual <a class="el" href="classOGRGeometry.html">OGRGeometry</a> * </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#adc3735e444204d46f517eec251712f4d">GetSpatialFilter</a> ()</td></tr> <tr class="memdesc:adc3735e444204d46f517eec251712f4d inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">This method returns the current spatial filter for this layer. <a href="#adc3735e444204d46f517eec251712f4d">More...</a><br/></td></tr> <tr class="separator:adc3735e444204d46f517eec251712f4d inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:acd16bcdb3e8f720003fb24cd68f25460 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#acd16bcdb3e8f720003fb24cd68f25460">SetSpatialFilterRect</a> (double dfMinX, double dfMinY, double dfMaxX, double dfMaxY)</td></tr> <tr class="memdesc:acd16bcdb3e8f720003fb24cd68f25460 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Set a new rectangular spatial filter. <a href="#acd16bcdb3e8f720003fb24cd68f25460">More...</a><br/></td></tr> <tr class="separator:acd16bcdb3e8f720003fb24cd68f25460 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a5cd4ceb8f4ec20594be63280c8e4498a inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#a5cd4ceb8f4ec20594be63280c8e4498a">SetSpatialFilterRect</a> (int iGeomField, double dfMinX, double dfMinY, double dfMaxX, double dfMaxY)</td></tr> <tr class="memdesc:a5cd4ceb8f4ec20594be63280c8e4498a inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Set a new rectangular spatial filter. <a href="#a5cd4ceb8f4ec20594be63280c8e4498a">More...</a><br/></td></tr> <tr class="separator:a5cd4ceb8f4ec20594be63280c8e4498a inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:ae3b6234d6077a18a19eddaf7e75ff5e1 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#ae3b6234d6077a18a19eddaf7e75ff5e1">SetNextByIndex</a> (long nIndex)</td></tr> <tr class="memdesc:ae3b6234d6077a18a19eddaf7e75ff5e1 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Move read cursor to the nIndex'th feature in the current resultset. <a href="#ae3b6234d6077a18a19eddaf7e75ff5e1">More...</a><br/></td></tr> <tr class="separator:ae3b6234d6077a18a19eddaf7e75ff5e1 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a7e3d454d54a615a1b4359628bb6e7674 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#a7e3d454d54a615a1b4359628bb6e7674">DeleteFeature</a> (long nFID)</td></tr> <tr class="memdesc:a7e3d454d54a615a1b4359628bb6e7674 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Delete feature from layer. <a href="#a7e3d454d54a615a1b4359628bb6e7674">More...</a><br/></td></tr> <tr class="separator:a7e3d454d54a615a1b4359628bb6e7674 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:aef41bcd7adad1ac5ddcef54d6b38713c inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual int </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#aef41bcd7adad1ac5ddcef54d6b38713c">FindFieldIndex</a> (const char *pszFieldName, int bExactMatch)</td></tr> <tr class="memdesc:aef41bcd7adad1ac5ddcef54d6b38713c inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Find the index of field in the layer. <a href="#aef41bcd7adad1ac5ddcef54d6b38713c">More...</a><br/></td></tr> <tr class="separator:aef41bcd7adad1ac5ddcef54d6b38713c inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a143b0d2c48bc0adf3a19d1f51e76b8ba inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual const char * </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#a143b0d2c48bc0adf3a19d1f51e76b8ba">GetInfo</a> (const char *)</td></tr> <tr class="memdesc:a143b0d2c48bc0adf3a19d1f51e76b8ba inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Fetch metadata from layer. <a href="#a143b0d2c48bc0adf3a19d1f51e76b8ba">More...</a><br/></td></tr> <tr class="separator:a143b0d2c48bc0adf3a19d1f51e76b8ba inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a00b1376a1eabb1298ef278f92f6d84be inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#a00b1376a1eabb1298ef278f92f6d84be">CreateField</a> (<a class="el" href="classOGRFieldDefn.html">OGRFieldDefn</a> *poField, int bApproxOK=TRUE)</td></tr> <tr class="memdesc:a00b1376a1eabb1298ef278f92f6d84be inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Create a new field on a layer. <a href="#a00b1376a1eabb1298ef278f92f6d84be">More...</a><br/></td></tr> <tr class="separator:a00b1376a1eabb1298ef278f92f6d84be inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:aaebe7c671dca995549543eecf0f7a76a inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#aaebe7c671dca995549543eecf0f7a76a">DeleteField</a> (int iField)</td></tr> <tr class="memdesc:aaebe7c671dca995549543eecf0f7a76a inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Delete an existing field on a layer. <a href="#aaebe7c671dca995549543eecf0f7a76a">More...</a><br/></td></tr> <tr class="separator:aaebe7c671dca995549543eecf0f7a76a inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:aebd364a150d91f8d65d967646e0f92d3 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#aebd364a150d91f8d65d967646e0f92d3">ReorderFields</a> (int *panMap)</td></tr> <tr class="memdesc:aebd364a150d91f8d65d967646e0f92d3 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Reorder all the fields of a layer. <a href="#aebd364a150d91f8d65d967646e0f92d3">More...</a><br/></td></tr> <tr class="separator:aebd364a150d91f8d65d967646e0f92d3 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a71e69a665e93001d48a4339695f33c1a inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#a71e69a665e93001d48a4339695f33c1a">AlterFieldDefn</a> (int iField, <a class="el" href="classOGRFieldDefn.html">OGRFieldDefn</a> *poNewFieldDefn, int nFlags)</td></tr> <tr class="memdesc:a71e69a665e93001d48a4339695f33c1a inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Alter the definition of an existing field on a layer. <a href="#a71e69a665e93001d48a4339695f33c1a">More...</a><br/></td></tr> <tr class="separator:a71e69a665e93001d48a4339695f33c1a inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:af3c68cad279ad80a476c6fb307cf5e48 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#af3c68cad279ad80a476c6fb307cf5e48">CreateGeomField</a> (<a class="el" href="classOGRGeomFieldDefn.html">OGRGeomFieldDefn</a> *poField, int bApproxOK=TRUE)</td></tr> <tr class="memdesc:af3c68cad279ad80a476c6fb307cf5e48 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Create a new geometry field on a layer. <a href="#af3c68cad279ad80a476c6fb307cf5e48">More...</a><br/></td></tr> <tr class="separator:af3c68cad279ad80a476c6fb307cf5e48 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:ac65f762d5b3c6fc4ca0f0cc4aafcdcbe inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual <a class="el" href="classOGRStyleTable.html">OGRStyleTable</a> * </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#ac65f762d5b3c6fc4ca0f0cc4aafcdcbe">GetStyleTable</a> ()</td></tr> <tr class="memdesc:ac65f762d5b3c6fc4ca0f0cc4aafcdcbe inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Returns layer style table. <a href="#ac65f762d5b3c6fc4ca0f0cc4aafcdcbe">More...</a><br/></td></tr> <tr class="separator:ac65f762d5b3c6fc4ca0f0cc4aafcdcbe inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a2687d4312c044bb3a20bd13974ba8905 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#a2687d4312c044bb3a20bd13974ba8905">SetStyleTableDirectly</a> (<a class="el" href="classOGRStyleTable.html">OGRStyleTable</a> *poStyleTable)</td></tr> <tr class="memdesc:a2687d4312c044bb3a20bd13974ba8905 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Set layer style table. <a href="#a2687d4312c044bb3a20bd13974ba8905">More...</a><br/></td></tr> <tr class="separator:a2687d4312c044bb3a20bd13974ba8905 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a33fa0802c0686fb0e6ca6337e11cd7d5 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual void </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#a33fa0802c0686fb0e6ca6337e11cd7d5">SetStyleTable</a> (<a class="el" href="classOGRStyleTable.html">OGRStyleTable</a> *poStyleTable)</td></tr> <tr class="memdesc:a33fa0802c0686fb0e6ca6337e11cd7d5 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Set layer style table. <a href="#a33fa0802c0686fb0e6ca6337e11cd7d5">More...</a><br/></td></tr> <tr class="separator:a33fa0802c0686fb0e6ca6337e11cd7d5 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:af0cb9a05310d7b17d9dfec9e83a18e61 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual const char * </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#af0cb9a05310d7b17d9dfec9e83a18e61">GetFIDColumn</a> ()</td></tr> <tr class="memdesc:af0cb9a05310d7b17d9dfec9e83a18e61 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">This method returns the name of the underlying database column being used as the FID column, or "" if not supported. <a href="#af0cb9a05310d7b17d9dfec9e83a18e61">More...</a><br/></td></tr> <tr class="separator:af0cb9a05310d7b17d9dfec9e83a18e61 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:af68036c23622c954ce3a91861f22b724 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">virtual const char * </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#af68036c23622c954ce3a91861f22b724">GetGeometryColumn</a> ()</td></tr> <tr class="memdesc:af68036c23622c954ce3a91861f22b724 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">This method returns the name of the underlying database column being used as the geometry column, or "" if not supported. <a href="#af68036c23622c954ce3a91861f22b724">More...</a><br/></td></tr> <tr class="separator:af68036c23622c954ce3a91861f22b724 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:ac189f54996c2d6fd769889ec99e0f48a inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#ac189f54996c2d6fd769889ec99e0f48a">Intersection</a> (<a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerMethod, <a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerResult, char **papszOptions=NULL, GDALProgressFunc pfnProgress=NULL, void *pProgressArg=NULL)</td></tr> <tr class="memdesc:ac189f54996c2d6fd769889ec99e0f48a inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Intersection of two layers. <a href="#ac189f54996c2d6fd769889ec99e0f48a">More...</a><br/></td></tr> <tr class="separator:ac189f54996c2d6fd769889ec99e0f48a inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:aeb8ab475561f2aca2c0e605cfb810b22 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#aeb8ab475561f2aca2c0e605cfb810b22">Union</a> (<a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerMethod, <a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerResult, char **papszOptions=NULL, GDALProgressFunc pfnProgress=NULL, void *pProgressArg=NULL)</td></tr> <tr class="memdesc:aeb8ab475561f2aca2c0e605cfb810b22 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Union of two layers. <a href="#aeb8ab475561f2aca2c0e605cfb810b22">More...</a><br/></td></tr> <tr class="separator:aeb8ab475561f2aca2c0e605cfb810b22 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a781aa76c6b44b19de09f61816e32245b inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#a781aa76c6b44b19de09f61816e32245b">SymDifference</a> (<a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerMethod, <a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerResult, char **papszOptions, GDALProgressFunc pfnProgress, void *pProgressArg)</td></tr> <tr class="memdesc:a781aa76c6b44b19de09f61816e32245b inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Symmetrical difference of two layers. <a href="#a781aa76c6b44b19de09f61816e32245b">More...</a><br/></td></tr> <tr class="separator:a781aa76c6b44b19de09f61816e32245b inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:acac6a0bde9737555b22c6ac7fa967431 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#acac6a0bde9737555b22c6ac7fa967431">Identity</a> (<a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerMethod, <a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerResult, char **papszOptions=NULL, GDALProgressFunc pfnProgress=NULL, void *pProgressArg=NULL)</td></tr> <tr class="memdesc:acac6a0bde9737555b22c6ac7fa967431 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Identify the features of this layer with the ones from the identity layer. <a href="#acac6a0bde9737555b22c6ac7fa967431">More...</a><br/></td></tr> <tr class="separator:acac6a0bde9737555b22c6ac7fa967431 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:aa1c5dc5ca195956c46d35a85b0b21d9b inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#aa1c5dc5ca195956c46d35a85b0b21d9b">Update</a> (<a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerMethod, <a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerResult, char **papszOptions=NULL, GDALProgressFunc pfnProgress=NULL, void *pProgressArg=NULL)</td></tr> <tr class="memdesc:aa1c5dc5ca195956c46d35a85b0b21d9b inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Update this layer with features from the update layer. <a href="#aa1c5dc5ca195956c46d35a85b0b21d9b">More...</a><br/></td></tr> <tr class="separator:aa1c5dc5ca195956c46d35a85b0b21d9b inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a56d7ee3b2020e53c730d67ee4f1e2fb6 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#a56d7ee3b2020e53c730d67ee4f1e2fb6">Clip</a> (<a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerMethod, <a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerResult, char **papszOptions=NULL, GDALProgressFunc pfnProgress=NULL, void *pProgressArg=NULL)</td></tr> <tr class="memdesc:a56d7ee3b2020e53c730d67ee4f1e2fb6 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Clip off areas that are not covered by the method layer. <a href="#a56d7ee3b2020e53c730d67ee4f1e2fb6">More...</a><br/></td></tr> <tr class="separator:a56d7ee3b2020e53c730d67ee4f1e2fb6 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:ae8fcf55ffa259f32df35edcb05274439 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#ae8fcf55ffa259f32df35edcb05274439">Erase</a> (<a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerMethod, <a class="el" href="classOGRLayer.html">OGRLayer</a> *pLayerResult, char **papszOptions=NULL, GDALProgressFunc pfnProgress=NULL, void *pProgressArg=NULL)</td></tr> <tr class="memdesc:ae8fcf55ffa259f32df35edcb05274439 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Remove areas that are covered by the method layer. <a href="#ae8fcf55ffa259f32df35edcb05274439">More...</a><br/></td></tr> <tr class="separator:ae8fcf55ffa259f32df35edcb05274439 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:ae783de2e9ee2629e6bf27fd3b8622fb5 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#ae783de2e9ee2629e6bf27fd3b8622fb5">Reference</a> ()</td></tr> <tr class="memdesc:ae783de2e9ee2629e6bf27fd3b8622fb5 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Increment layer reference count. <a href="#ae783de2e9ee2629e6bf27fd3b8622fb5">More...</a><br/></td></tr> <tr class="separator:ae783de2e9ee2629e6bf27fd3b8622fb5 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a2271d53f75d4f6ff2f4a8aeb71e825d6 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#a2271d53f75d4f6ff2f4a8aeb71e825d6">Dereference</a> ()</td></tr> <tr class="memdesc:a2271d53f75d4f6ff2f4a8aeb71e825d6 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Decrement layer reference count. <a href="#a2271d53f75d4f6ff2f4a8aeb71e825d6">More...</a><br/></td></tr> <tr class="separator:a2271d53f75d4f6ff2f4a8aeb71e825d6 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:a2fc393bc9962a73e94478b72d9fc4954 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#a2fc393bc9962a73e94478b72d9fc4954">GetRefCount</a> () const </td></tr> <tr class="memdesc:a2fc393bc9962a73e94478b72d9fc4954 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Fetch reference count. <a href="#a2fc393bc9962a73e94478b72d9fc4954">More...</a><br/></td></tr> <tr class="separator:a2fc393bc9962a73e94478b72d9fc4954 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> <tr class="memitem:ab4c02b991bfa78552eeb0cbcdcf1aed8 inherit pub_methods_classOGRLayer"><td class="memItemLeft" align="right" valign="top">OGRErr </td><td class="memItemRight" valign="bottom"><a class="el" href="classOGRLayer.html#ab4c02b991bfa78552eeb0cbcdcf1aed8">ReorderField</a> (int iOldFieldPos, int iNewFieldPos)</td></tr> <tr class="memdesc:ab4c02b991bfa78552eeb0cbcdcf1aed8 inherit pub_methods_classOGRLayer"><td class="mdescLeft"> </td><td class="mdescRight">Reorder an existing field on a layer. <a href="#ab4c02b991bfa78552eeb0cbcdcf1aed8">More...</a><br/></td></tr> <tr class="separator:ab4c02b991bfa78552eeb0cbcdcf1aed8 inherit pub_methods_classOGRLayer"><td class="memSeparator" colspan="2"> </td></tr> </table> <h2 class="groupheader">Member Function Documentation</h2> <a class="anchor" id="a094a2f13809f0b2eaabbc572ddfc19ed"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">OGRErr OGRUnionLayer::CreateFeature </td> <td>(</td> <td class="paramtype"><a class="el" href="classOGRFeature.html">OGRFeature</a> * </td> <td class="paramname"><em>poFeature</em></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Create and write a new feature within a layer. </p> <p>The passed feature is written to the layer as a new feature, rather than overwriting an existing one. If the feature has a feature id other than OGRNullFID, then the native implementation may use that as the feature id of the new feature, but not necessarily. Upon successful return the passed feature will have been updated with the new feature id.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a301d319111285a47fe6cda6e079214f8" title="Create and write a new feature within a layer. ">OGR_L_CreateFeature()</a>.</p> <dl class="params"><dt>Parameters</dt><dd> <table class="params"> <tr><td class="paramname">poFeature</td><td>the feature to write to disk.</td></tr> </table> </dd> </dl> <dl class="section return"><dt>Returns</dt><dd>OGRERR_NONE on success. </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#aaa1e32016f481596a55e1d988a15a067">OGRLayer</a>.</p> <p>References <a class="el" href="cpl__error_8h.html#aad2b98dd58e4de706a245faddac90403">CPLError()</a>, <a class="el" href="classOGRLayer.html#aaa1e32016f481596a55e1d988a15a067">OGRLayer::CreateFeature()</a>, <a class="el" href="classOGRFeature.html#a23506b436ea8e88e65aaa6b57bbaa326">OGRFeature::GetFID()</a>, <a class="el" href="classOGRFeature.html#ac7a0224e13dce1f9479a6bf2111ea766">OGRFeature::GetFieldAsString()</a>, <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9">GetLayerDefn()</a>, <a class="el" href="classOGRUnionLayer.html#a530eaa40528ad609ae506336103fbedf">GetName()</a>, <a class="el" href="classOGRFeature.html#a7ad01c76b7b13bcf9eab5092aacac5fb">OGRFeature::IsFieldSet()</a>, <a class="el" href="classOGRFeature.html#a9abfc256b2d1758761fa54ca3395029b">OGRFeature::SetFID()</a>, and <a class="el" href="classOGRFeature.html#a8ebc0999c4bce0b5073add16598dfc77">OGRFeature::SetFrom()</a>.</p> </div> </div> <a class="anchor" id="a36e1634fb7f68fae343179a6007960c4"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">OGRErr OGRUnionLayer::GetExtent </td> <td>(</td> <td class="paramtype">int </td> <td class="paramname"><em>iGeomField</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype"><a class="el" href="classOGREnvelope.html">OGREnvelope</a> * </td> <td class="paramname"><em>psExtent</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype">int </td> <td class="paramname"><em>bForce</em> = <code>TRUE</code> </td> </tr> <tr> <td></td> <td>)</td> <td></td><td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Fetch the extent of this layer, on the specified geometry field. </p> <p>Returns the extent (MBR) of the data in the layer. If bForce is FALSE, and it would be expensive to establish the extent then OGRERR_FAILURE will be returned indicating that the extent isn't know. If bForce is TRUE then some implementations will actually scan the entire layer once to compute the MBR of all the features in the layer.</p> <p>Depending on the drivers, the returned extent may or may not take the spatial filter into account. So it is safer to call <a class="el" href="classOGRUnionLayer.html#a36e1634fb7f68fae343179a6007960c4" title="Fetch the extent of this layer, on the specified geometry field. ">GetExtent()</a> without setting a spatial filter.</p> <p>Layers without any geometry may return OGRERR_FAILURE just indicating that no meaningful extents could be collected.</p> <p>Note that some implementations of this method may alter the read cursor of the layer.</p> <p>Note to driver implementators: if you implement <a class="el" href="classOGRUnionLayer.html#a36e1634fb7f68fae343179a6007960c4" title="Fetch the extent of this layer, on the specified geometry field. ">GetExtent(int,OGREnvelope*,int)</a>, you must also implement <a class="el" href="classOGRUnionLayer.html#a3c80b4bddf35c4951b307929fa17228e" title="Fetch the extent of this layer. ">GetExtent(OGREnvelope*, int)</a> to make it call GetExtent(0,OGREnvelope*,int).</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#ac3dbfd4443c80dca0d93574f0c00d376" title="Fetch the extent of this layer, on the specified geometry field. ">OGR_L_GetExtentEx()</a>.</p> <dl class="params"><dt>Parameters</dt><dd> <table class="params"> <tr><td class="paramname">iGeomField</td><td>the index of the geometry field on which to compute the extent. </td></tr> <tr><td class="paramname">psExtent</td><td>the structure in which the extent value will be returned. </td></tr> <tr><td class="paramname">bForce</td><td>Flag indicating whether the extent should be computed even if it is expensive.</td></tr> </table> </dd> </dl> <dl class="section return"><dt>Returns</dt><dd>OGRERR_NONE on success, OGRERR_FAILURE if extent not known. </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#a47a3cc550866eee1668bea2315f9df9c">OGRLayer</a>.</p> <p>References <a class="el" href="cpl__error_8h.html#aad2b98dd58e4de706a245faddac90403">CPLError()</a>, <a class="el" href="classOGRFeatureDefn.html#a2aaea18e9bcfee39cee05d616de6e12c">OGRFeatureDefn::GetGeomFieldIndex()</a>, <a class="el" href="classOGRLayer.html#a80473bcfd11341e70dd35bebe94026cf">OGRLayer::GetLayerDefn()</a>, and <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9">GetLayerDefn()</a>.</p> <p>Referenced by <a class="el" href="classOGRUnionLayer.html#a3c80b4bddf35c4951b307929fa17228e">GetExtent()</a>.</p> </div> </div> <a class="anchor" id="a3c80b4bddf35c4951b307929fa17228e"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">OGRErr OGRUnionLayer::GetExtent </td> <td>(</td> <td class="paramtype"><a class="el" href="classOGREnvelope.html">OGREnvelope</a> * </td> <td class="paramname"><em>psExtent</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype">int </td> <td class="paramname"><em>bForce</em> </td> </tr> <tr> <td></td> <td>)</td> <td></td><td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Fetch the extent of this layer. </p> <p>Returns the extent (MBR) of the data in the layer. If bForce is FALSE, and it would be expensive to establish the extent then OGRERR_FAILURE will be returned indicating that the extent isn't know. If bForce is TRUE then some implementations will actually scan the entire layer once to compute the MBR of all the features in the layer.</p> <p>Depending on the drivers, the returned extent may or may not take the spatial filter into account. So it is safer to call <a class="el" href="classOGRUnionLayer.html#a36e1634fb7f68fae343179a6007960c4" title="Fetch the extent of this layer, on the specified geometry field. ">GetExtent()</a> without setting a spatial filter.</p> <p>Layers without any geometry may return OGRERR_FAILURE just indicating that no meaningful extents could be collected.</p> <p>Note that some implementations of this method may alter the read cursor of the layer.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#aa6c495581900c8301dff91d8cd3ee12f" title="Fetch the extent of this layer. ">OGR_L_GetExtent()</a>.</p> <dl class="params"><dt>Parameters</dt><dd> <table class="params"> <tr><td class="paramname">psExtent</td><td>the structure in which the extent value will be returned. </td></tr> <tr><td class="paramname">bForce</td><td>Flag indicating whether the extent should be computed even if it is expensive.</td></tr> </table> </dd> </dl> <dl class="section return"><dt>Returns</dt><dd>OGRERR_NONE on success, OGRERR_FAILURE if extent not known. </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#a3be658ddb5b33d1ed95c31286774bbd2">OGRLayer</a>.</p> <p>References <a class="el" href="classOGRUnionLayer.html#a36e1634fb7f68fae343179a6007960c4">GetExtent()</a>.</p> </div> </div> <a class="anchor" id="a58427b11107fee76162055092e2364d2"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname"><a class="el" href="classOGRFeature.html">OGRFeature</a> * OGRUnionLayer::GetFeature </td> <td>(</td> <td class="paramtype">long </td> <td class="paramname"><em>nFID</em></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Fetch a feature by its identifier. </p> <p>This function will attempt to read the identified feature. The nFID value cannot be OGRNullFID. Success or failure of this operation is unaffected by the spatial or attribute filters (and specialized implementations in drivers should make sure that they do not take into account spatial or attribute filters).</p> <p>If this method returns a non-NULL feature, it is guaranteed that its feature id (<a class="el" href="classOGRFeature.html#a23506b436ea8e88e65aaa6b57bbaa326" title="Get feature identifier. ">OGRFeature::GetFID()</a>) will be the same as nFID.</p> <p>Use OGRLayer::TestCapability(OLCRandomRead) to establish if this layer supports efficient random access reading via <a class="el" href="classOGRUnionLayer.html#a58427b11107fee76162055092e2364d2" title="Fetch a feature by its identifier. ">GetFeature()</a>; however, the call should always work if the feature exists as a fallback implementation just scans all the features in the layer looking for the desired feature.</p> <p>Sequential reads (with <a class="el" href="classOGRUnionLayer.html#a1ff231230bc51b63952c49fbf565d2b8" title="Fetch the next available feature from this layer. ">GetNextFeature()</a>) are generally considered interrupted by a <a class="el" href="classOGRUnionLayer.html#a58427b11107fee76162055092e2364d2" title="Fetch a feature by its identifier. ">GetFeature()</a> call.</p> <p>The returned feature should be free with <a class="el" href="classOGRFeature.html#a5d2602d11f21567119da0ca6b6c5ad45" title="Destroy feature. ">OGRFeature::DestroyFeature()</a>.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a7c628dce8939904154b50365306b06f9" title="Fetch a feature by its identifier. ">OGR_L_GetFeature()</a>.</p> <dl class="params"><dt>Parameters</dt><dd> <table class="params"> <tr><td class="paramname">nFID</td><td>the feature id of the feature to read.</td></tr> </table> </dd> </dl> <dl class="section return"><dt>Returns</dt><dd>a feature now owned by the caller, or NULL on failure. </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#acb7625383f161e5a04aeea2173dce411">OGRLayer</a>.</p> <p>References <a class="el" href="classOGRLayer.html#acb7625383f161e5a04aeea2173dce411">OGRLayer::GetFeature()</a>, <a class="el" href="classOGRUnionLayer.html#a20c1d59b04f816722d0d6f865f079273">ResetReading()</a>, and <a class="el" href="classOGRUnionLayer.html#a194555741a74ee0e61c92875683cce7f">SetSpatialFilter()</a>.</p> </div> </div> <a class="anchor" id="a6f9c4f51181cb7db75b08a6b81182e67"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">int OGRUnionLayer::GetFeatureCount </td> <td>(</td> <td class="paramtype">int </td> <td class="paramname"><em>bForce</em></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Fetch the feature count in this layer. </p> <p>Returns the number of features in the layer. For dynamic databases the count may not be exact. If bForce is FALSE, and it would be expensive to establish the feature count a value of -1 may be returned indicating that the count isn't know. If bForce is TRUE some implementations will actually scan the entire layer once to count objects.</p> <p>The returned count takes the spatial filter into account.</p> <p>Note that some implementations of this method may alter the read cursor of the layer.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#abfbba8f45edd5dc44ced91f9228f9124" title="Fetch the feature count in this layer. ">OGR_L_GetFeatureCount()</a>.</p> <dl class="params"><dt>Parameters</dt><dd> <table class="params"> <tr><td class="paramname">bForce</td><td>Flag indicating whether the count should be computed even if it is expensive.</td></tr> </table> </dd> </dl> <dl class="section return"><dt>Returns</dt><dd>feature count, -1 if count not known. </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#a74c796d4ce712e9a78df6042eeb8a91a">OGRLayer</a>.</p> <p>References <a class="el" href="classOGRLayer.html#a74c796d4ce712e9a78df6042eeb8a91a">OGRLayer::GetFeatureCount()</a>, and <a class="el" href="classOGRUnionLayer.html#a20c1d59b04f816722d0d6f865f079273">ResetReading()</a>.</p> </div> </div> <a class="anchor" id="a11d7365a8f7264b0cc0bfc3cd371aac7"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname"><a class="el" href="ogr__core_8h.html#a800236a0d460ef66e687b7b65610f12a">OGRwkbGeometryType</a> OGRUnionLayer::GetGeomType </td> <td>(</td> <td class="paramname"></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Return the layer geometry type. </p> <p>This returns the same result as <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9" title="Fetch the schema information for this layer. ">GetLayerDefn()</a>-><a class="el" href="classOGRUnionLayer.html#a11d7365a8f7264b0cc0bfc3cd371aac7" title="Return the layer geometry type. ">GetGeomType()</a>, but for a few drivers, calling <a class="el" href="classOGRUnionLayer.html#a11d7365a8f7264b0cc0bfc3cd371aac7" title="Return the layer geometry type. ">GetGeomType()</a> directly can avoid lengthy layer definition initialization.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a0adea8ce1ca795ce0a6a76505f90f078" title="Return the layer geometry type. ">OGR_L_GetGeomType()</a>.</p> <p>If this method is derived in a driver, it must be done such that it returns the same content as <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9" title="Fetch the schema information for this layer. ">GetLayerDefn()</a>-><a class="el" href="classOGRUnionLayer.html#a11d7365a8f7264b0cc0bfc3cd371aac7" title="Return the layer geometry type. ">GetGeomType()</a>.</p> <dl class="section return"><dt>Returns</dt><dd>the geometry type </dd></dl> <dl class="section since"><dt>Since</dt><dd>OGR 1.8.0 </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#a818a25520ce08d5a681443348e930604">OGRLayer</a>.</p> <p>References <a class="el" href="classOGRLayer.html#a818a25520ce08d5a681443348e930604">OGRLayer::GetGeomType()</a>, <a class="el" href="classOGRGeomFieldDefn.html#a1b628044cd6d2142a1732f5c5ef41bd6">OGRGeomFieldDefn::GetType()</a>, and <a class="el" href="ogr__core_8h.html#a800236a0d460ef66e687b7b65610f12aa988c33f9e94f35d2081e5882d4167ec6">wkbNone</a>.</p> </div> </div> <a class="anchor" id="a4c680d7e5c02454ea7361f341d6d54e9"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname"><a class="el" href="classOGRFeatureDefn.html">OGRFeatureDefn</a> * OGRUnionLayer::GetLayerDefn </td> <td>(</td> <td class="paramname"></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Fetch the schema information for this layer. </p> <p>The returned <a class="el" href="classOGRFeatureDefn.html">OGRFeatureDefn</a> is owned by the <a class="el" href="classOGRLayer.html">OGRLayer</a>, and should not be modified or freed by the application. It encapsulates the attribute schema of the features of the layer.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a7b67ea4ab5892c6720460dc7f66eca2d" title="Fetch the schema information for this layer. ">OGR_L_GetLayerDefn()</a>.</p> <dl class="section return"><dt>Returns</dt><dd>feature definition. </dd></dl> <p>Implements <a class="el" href="classOGRLayer.html#a80473bcfd11341e70dd35bebe94026cf">OGRLayer</a>.</p> <p>References <a class="el" href="classOGRFeatureDefn.html#a40e681d8464b42f1a1fac655f16ac3dd">OGRFeatureDefn::AddFieldDefn()</a>, <a class="el" href="classOGRFeatureDefn.html#a99700a7f755c91c3382eaa65bc49f4f9">OGRFeatureDefn::AddGeomFieldDefn()</a>, <a class="el" href="classOGRFeatureDefn.html#ada48e1a3e90798bdccc2dd26f32f48cb">OGRFeatureDefn::DeleteFieldDefn()</a>, <a class="el" href="classOGRFeatureDefn.html#a2c67a35c58cfd9ac384858d1b7b7ec48">OGRFeatureDefn::DeleteGeomFieldDefn()</a>, <a class="el" href="classOGRFeatureDefn.html#ab400f9106e7544ebafa30b1fe59869b1">OGRFeatureDefn::GetFieldCount()</a>, <a class="el" href="classOGRFeatureDefn.html#a43b95ce699bbca73acb453cc959378e7">OGRFeatureDefn::GetFieldDefn()</a>, <a class="el" href="classOGRFeatureDefn.html#a4f7111e4c818f194932795e9c9593258">OGRFeatureDefn::GetFieldIndex()</a>, <a class="el" href="classOGRFeatureDefn.html#aa4a41bcd09868d325d214c28e17717eb">OGRFeatureDefn::GetGeomFieldCount()</a>, <a class="el" href="classOGRFeatureDefn.html#acacca3de3718ae525565e5130b5474dc">OGRFeatureDefn::GetGeomFieldDefn()</a>, <a class="el" href="classOGRFeatureDefn.html#a2aaea18e9bcfee39cee05d616de6e12c">OGRFeatureDefn::GetGeomFieldIndex()</a>, <a class="el" href="classOGRLayer.html#a80473bcfd11341e70dd35bebe94026cf">OGRLayer::GetLayerDefn()</a>, <a class="el" href="classOGRFieldDefn.html#a7754d32a36e4ba854f71f511a5ca7740">OGRFieldDefn::GetNameRef()</a>, <a class="el" href="classOGRGeomFieldDefn.html#a8dbbb2a2630752eda8702cd4196ed4c6">OGRGeomFieldDefn::GetNameRef()</a>, <a class="el" href="classOGRUnionLayer.html#a8223e23c723151ef11fba997ab4fc605">GetSpatialRef()</a>, <a class="el" href="classOGRGeomFieldDefn.html#ae043691f36413950ea2ec0c3495ac959">OGRGeomFieldDefn::GetSpatialRef()</a>, <a class="el" href="classOGRGeomFieldDefn.html#a1b628044cd6d2142a1732f5c5ef41bd6">OGRGeomFieldDefn::GetType()</a>, <a class="el" href="ogr__core_8h.html#a787194bea637faf12d61643124a7c9fca862a7b8506c67c5390c2e0860c4edf45">OFTString</a>, <a class="el" href="classOGRSpatialReference.html#a4b638c33c0a2b53e59fe694f26f8f89c">OGRSpatialReference::Reference()</a>, <a class="el" href="classOGRFeatureDefn.html#a2c58c6238242dff3d472faf5e3803922">OGRFeatureDefn::Reference()</a>, <a class="el" href="classOGRFeatureDefn.html#aa0f50b39efbba6559a510d7afcfa5efb">OGRFeatureDefn::SetGeomType()</a>, <a class="el" href="classOGRGeomFieldDefn.html#aeae0b00cc5a55b49aa51262d0a736bae">OGRGeomFieldDefn::SetSpatialRef()</a>, <a class="el" href="classOGRGeomFieldDefn.html#a9b030e08d01a09b1917c1d01638a4ac8">OGRGeomFieldDefn::SetType()</a>, and <a class="el" href="ogr__core_8h.html#a800236a0d460ef66e687b7b65610f12aa988c33f9e94f35d2081e5882d4167ec6">wkbNone</a>.</p> <p>Referenced by <a class="el" href="classOGRUnionLayer.html#a094a2f13809f0b2eaabbc572ddfc19ed">CreateFeature()</a>, <a class="el" href="classOGRUnionLayer.html#a36e1634fb7f68fae343179a6007960c4">GetExtent()</a>, <a class="el" href="classOGRUnionLayer.html#a1ff231230bc51b63952c49fbf565d2b8">GetNextFeature()</a>, <a class="el" href="classOGRUnionLayer.html#a2231dba322c7cfbc5914e2201d27c610">SetAttributeFilter()</a>, <a class="el" href="classOGRUnionLayer.html#ab44d7c6a95d8d6a73f906f60760c0c56">SetFeature()</a>, and <a class="el" href="classOGRUnionLayer.html#a2ece59929973a6f19a95443e45ffccad">SetSpatialFilter()</a>.</p> </div> </div> <a class="anchor" id="a530eaa40528ad609ae506336103fbedf"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">virtual const char* OGRUnionLayer::GetName </td> <td>(</td> <td class="paramname"></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">inline</span><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Return the layer name. </p> <p>This returns the same content as <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9" title="Fetch the schema information for this layer. ">GetLayerDefn()</a>-><a class="el" href="classOGRUnionLayer.html#a530eaa40528ad609ae506336103fbedf" title="Return the layer name. ">GetName()</a>, but for a few drivers, calling <a class="el" href="classOGRUnionLayer.html#a530eaa40528ad609ae506336103fbedf" title="Return the layer name. ">GetName()</a> directly can avoid lengthy layer definition initialization.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a88facf4f8e8b32278101d52ae094255c" title="Return the layer name. ">OGR_L_GetName()</a>.</p> <p>If this method is derived in a driver, it must be done such that it returns the same content as <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9" title="Fetch the schema information for this layer. ">GetLayerDefn()</a>-><a class="el" href="classOGRUnionLayer.html#a530eaa40528ad609ae506336103fbedf" title="Return the layer name. ">GetName()</a>.</p> <dl class="section return"><dt>Returns</dt><dd>the layer name (must not been freed) </dd></dl> <dl class="section since"><dt>Since</dt><dd>OGR 1.8.0 </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#a287f5ec7728cacc2f7d94882a9f1a22e">OGRLayer</a>.</p> <p>Referenced by <a class="el" href="classOGRUnionLayer.html#a094a2f13809f0b2eaabbc572ddfc19ed">CreateFeature()</a>, and <a class="el" href="classOGRUnionLayer.html#ab44d7c6a95d8d6a73f906f60760c0c56">SetFeature()</a>.</p> </div> </div> <a class="anchor" id="a1ff231230bc51b63952c49fbf565d2b8"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname"><a class="el" href="classOGRFeature.html">OGRFeature</a> * OGRUnionLayer::GetNextFeature </td> <td>(</td> <td class="paramname"></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Fetch the next available feature from this layer. </p> <p>The returned feature becomes the responsiblity of the caller to delete with <a class="el" href="classOGRFeature.html#a5d2602d11f21567119da0ca6b6c5ad45" title="Destroy feature. ">OGRFeature::DestroyFeature()</a>. It is critical that all features associated with an <a class="el" href="classOGRLayer.html">OGRLayer</a> (more specifically an <a class="el" href="classOGRFeatureDefn.html">OGRFeatureDefn</a>) be deleted before that layer/datasource is deleted.</p> <p>Only features matching the current spatial filter (set with <a class="el" href="classOGRUnionLayer.html#a194555741a74ee0e61c92875683cce7f" title="Set a new spatial filter. ">SetSpatialFilter()</a>) will be returned.</p> <p>This method implements sequential access to the features of a layer. The <a class="el" href="classOGRUnionLayer.html#a20c1d59b04f816722d0d6f865f079273" title="Reset feature reading to start on the first feature. ">ResetReading()</a> method can be used to start at the beginning again.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a6708c067521ab7b7f9c4ec0ebe221b5b" title="Fetch the next available feature from this layer. ">OGR_L_GetNextFeature()</a>.</p> <dl class="section return"><dt>Returns</dt><dd>a feature, or NULL if no more features are available. </dd></dl> <p>Implements <a class="el" href="classOGRLayer.html#a47d21ff33b32d14fa4e9885b9edecad6">OGRLayer</a>.</p> <p>References <a class="el" href="classOGRFeature.html#ae54d999d4649730d5c7b37de731e4f69">OGRFeature::GetGeomFieldRef()</a>, <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9">GetLayerDefn()</a>, <a class="el" href="classOGRLayer.html#a47d21ff33b32d14fa4e9885b9edecad6">OGRLayer::GetNextFeature()</a>, and <a class="el" href="classOGRUnionLayer.html#a20c1d59b04f816722d0d6f865f079273">ResetReading()</a>.</p> </div> </div> <a class="anchor" id="a8223e23c723151ef11fba997ab4fc605"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname"><a class="el" href="classOGRSpatialReference.html">OGRSpatialReference</a> * OGRUnionLayer::GetSpatialRef </td> <td>(</td> <td class="paramname"></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Fetch the spatial reference system for this layer. </p> <p>The returned object is owned by the <a class="el" href="classOGRLayer.html">OGRLayer</a> and should not be modified or freed by the application.</p> <p>Starting with OGR 1.11, several geometry fields can be associated to a feature definition. Each geometry field can have its own spatial reference system, which is returned by <a class="el" href="classOGRGeomFieldDefn.html#ae043691f36413950ea2ec0c3495ac959" title="Fetch spatial reference system of this field. ">OGRGeomFieldDefn::GetSpatialRef()</a>. <a class="el" href="classOGRLayer.html#a75c06b4993f8eb76b569f37365cd19ab" title="Fetch the spatial reference system for this layer. ">OGRLayer::GetSpatialRef()</a> is equivalent to <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9" title="Fetch the schema information for this layer. ">GetLayerDefn()</a>->GetGeomFieldDefn(0)-><a class="el" href="classOGRUnionLayer.html#a8223e23c723151ef11fba997ab4fc605" title="Fetch the spatial reference system for this layer. ">GetSpatialRef()</a></p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a8b2a10085f410aa84172eba413408c39" title="Fetch the spatial reference system for this layer. ">OGR_L_GetSpatialRef()</a>.</p> <dl class="section return"><dt>Returns</dt><dd>spatial reference, or NULL if there isn't one. </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#a75c06b4993f8eb76b569f37365cd19ab">OGRLayer</a>.</p> <p>References <a class="el" href="classOGRLayer.html#a75c06b4993f8eb76b569f37365cd19ab">OGRLayer::GetSpatialRef()</a>, <a class="el" href="classOGRGeomFieldDefn.html#ae043691f36413950ea2ec0c3495ac959">OGRGeomFieldDefn::GetSpatialRef()</a>, and <a class="el" href="classOGRSpatialReference.html#a4b638c33c0a2b53e59fe694f26f8f89c">OGRSpatialReference::Reference()</a>.</p> <p>Referenced by <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9">GetLayerDefn()</a>.</p> </div> </div> <a class="anchor" id="a20c1d59b04f816722d0d6f865f079273"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">void OGRUnionLayer::ResetReading </td> <td>(</td> <td class="paramname"></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Reset feature reading to start on the first feature. </p> <p>This affects <a class="el" href="classOGRUnionLayer.html#a1ff231230bc51b63952c49fbf565d2b8" title="Fetch the next available feature from this layer. ">GetNextFeature()</a>.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#ab0383004bf637171648a9d03a80f15a4" title="Reset feature reading to start on the first feature. ">OGR_L_ResetReading()</a>. </p> <p>Implements <a class="el" href="classOGRLayer.html#aad0f2cd7f0587584b8f382c6a913583c">OGRLayer</a>.</p> <p>Referenced by <a class="el" href="classOGRUnionLayer.html#a58427b11107fee76162055092e2364d2">GetFeature()</a>, <a class="el" href="classOGRUnionLayer.html#a6f9c4f51181cb7db75b08a6b81182e67">GetFeatureCount()</a>, <a class="el" href="classOGRUnionLayer.html#a1ff231230bc51b63952c49fbf565d2b8">GetNextFeature()</a>, and <a class="el" href="classOGRUnionLayer.html#a2ece59929973a6f19a95443e45ffccad">SetSpatialFilter()</a>.</p> </div> </div> <a class="anchor" id="a2231dba322c7cfbc5914e2201d27c610"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">OGRErr OGRUnionLayer::SetAttributeFilter </td> <td>(</td> <td class="paramtype">const char * </td> <td class="paramname"><em>pszQuery</em></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Set a new attribute query. </p> <p>This method sets the attribute query string to be used when fetching features via the <a class="el" href="classOGRUnionLayer.html#a1ff231230bc51b63952c49fbf565d2b8" title="Fetch the next available feature from this layer. ">GetNextFeature()</a> method. Only features for which the query evaluates as true will be returned.</p> <p>The query string should be in the format of an SQL WHERE clause. For instance "population > 1000000 and population < 5000000" where population is an attribute in the layer. The query format is normally a restricted form of SQL WHERE clause as described in the "WHERE" section of the <a href="ogr_sql.html">OGR SQL</a> tutorial. In some cases (RDBMS backed drivers) the native capabilities of the database may be used to interprete the WHERE clause in which case the capabilities will be broader than those of OGR SQL.</p> <p>Note that installing a query string will generally result in resetting the current reading position (ala <a class="el" href="classOGRUnionLayer.html#a20c1d59b04f816722d0d6f865f079273" title="Reset feature reading to start on the first feature. ">ResetReading()</a>).</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a4000d426bf26ad7cc7d4012634c93f09" title="Set a new attribute query. ">OGR_L_SetAttributeFilter()</a>.</p> <dl class="params"><dt>Parameters</dt><dd> <table class="params"> <tr><td class="paramname">pszQuery</td><td>query in restricted SQL WHERE format, or NULL to clear the current query.</td></tr> </table> </dd> </dl> <dl class="section return"><dt>Returns</dt><dd>OGRERR_NONE if successfully installed, or an error code if the query expression is in error, or some other failure occurs. </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#acb2c6cc5fa3577df5be538284c1b0dde">OGRLayer</a>.</p> <p>References <a class="el" href="cpl__conv_8h.html#a464d6861faf9f6272317d160a3ad9a81">CPLStrdup()</a>, <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9">GetLayerDefn()</a>, and <a class="el" href="classOGRLayer.html#acb2c6cc5fa3577df5be538284c1b0dde">OGRLayer::SetAttributeFilter()</a>.</p> </div> </div> <a class="anchor" id="ab44d7c6a95d8d6a73f906f60760c0c56"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">OGRErr OGRUnionLayer::SetFeature </td> <td>(</td> <td class="paramtype"><a class="el" href="classOGRFeature.html">OGRFeature</a> * </td> <td class="paramname"><em>poFeature</em></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Rewrite an existing feature. </p> <p>This method will write a feature to the layer, based on the feature id within the <a class="el" href="classOGRFeature.html">OGRFeature</a>.</p> <p>Use OGRLayer::TestCapability(OLCRandomWrite) to establish if this layer supports random access writing via <a class="el" href="classOGRUnionLayer.html#ab44d7c6a95d8d6a73f906f60760c0c56" title="Rewrite an existing feature. ">SetFeature()</a>.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a5b380520d0999422987f06b6e31b9b00" title="Rewrite an existing feature. ">OGR_L_SetFeature()</a>.</p> <dl class="params"><dt>Parameters</dt><dd> <table class="params"> <tr><td class="paramname">poFeature</td><td>the feature to write.</td></tr> </table> </dd> </dl> <dl class="section return"><dt>Returns</dt><dd>OGRERR_NONE if the operation works, otherwise an appropriate error code. </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#a681139bfd585b74d7218e51a32144283">OGRLayer</a>.</p> <p>References <a class="el" href="cpl__error_8h.html#aad2b98dd58e4de706a245faddac90403">CPLError()</a>, <a class="el" href="classOGRFeature.html#a23506b436ea8e88e65aaa6b57bbaa326">OGRFeature::GetFID()</a>, <a class="el" href="classOGRFeature.html#ac7a0224e13dce1f9479a6bf2111ea766">OGRFeature::GetFieldAsString()</a>, <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9">GetLayerDefn()</a>, <a class="el" href="classOGRUnionLayer.html#a530eaa40528ad609ae506336103fbedf">GetName()</a>, <a class="el" href="classOGRFeature.html#a7ad01c76b7b13bcf9eab5092aacac5fb">OGRFeature::IsFieldSet()</a>, <a class="el" href="classOGRLayer.html#a681139bfd585b74d7218e51a32144283">OGRLayer::SetFeature()</a>, <a class="el" href="classOGRFeature.html#a9abfc256b2d1758761fa54ca3395029b">OGRFeature::SetFID()</a>, and <a class="el" href="classOGRFeature.html#a8ebc0999c4bce0b5073add16598dfc77">OGRFeature::SetFrom()</a>.</p> </div> </div> <a class="anchor" id="a81737b724f0c7c0f81d593cec662bb08"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">OGRErr OGRUnionLayer::SetIgnoredFields </td> <td>(</td> <td class="paramtype">const char ** </td> <td class="paramname"><em>papszFields</em></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Set which fields can be omitted when retrieving features from the layer. </p> <p>If the driver supports this functionality (testable using OLCIgnoreFields capability), it will not fetch the specified fields in subsequent calls to <a class="el" href="classOGRUnionLayer.html#a58427b11107fee76162055092e2364d2" title="Fetch a feature by its identifier. ">GetFeature()</a> / <a class="el" href="classOGRUnionLayer.html#a1ff231230bc51b63952c49fbf565d2b8" title="Fetch the next available feature from this layer. ">GetNextFeature()</a> and thus save some processing time and/or bandwidth.</p> <p>Besides field names of the layers, the following special fields can be passed: "OGR_GEOMETRY" to ignore geometry and "OGR_STYLE" to ignore layer style.</p> <p>By default, no fields are ignored.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a6d43f1474201356bed2e6f92e7d37154" title="Set which fields can be omitted when retrieving features from the layer. ">OGR_L_SetIgnoredFields()</a></p> <dl class="params"><dt>Parameters</dt><dd> <table class="params"> <tr><td class="paramname">papszFields</td><td>an array of field names terminated by NULL item. If NULL is passed, the ignored list is cleared. </td></tr> </table> </dd> </dl> <dl class="section return"><dt>Returns</dt><dd>OGRERR_NONE if all field names have been resolved (even if the driver does not support this method) </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#a5e0c3427f64249d1c35cefb487546b10">OGRLayer</a>.</p> <p>References <a class="el" href="cpl__string_8h.html#a5a39b9c5896a273cc6f06c1d5be93238">CSLDestroy()</a>, <a class="el" href="cpl__string_8h.html#a8b9c9ad6c5a416c91f1fca55d9a91701">CSLDuplicate()</a>, and <a class="el" href="classOGRLayer.html#a5e0c3427f64249d1c35cefb487546b10">OGRLayer::SetIgnoredFields()</a>.</p> </div> </div> <a class="anchor" id="a194555741a74ee0e61c92875683cce7f"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">void OGRUnionLayer::SetSpatialFilter </td> <td>(</td> <td class="paramtype"><a class="el" href="classOGRGeometry.html">OGRGeometry</a> * </td> <td class="paramname"><em>poFilter</em></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Set a new spatial filter. </p> <p>This method set the geometry to be used as a spatial filter when fetching features via the <a class="el" href="classOGRUnionLayer.html#a1ff231230bc51b63952c49fbf565d2b8" title="Fetch the next available feature from this layer. ">GetNextFeature()</a> method. Only features that geometrically intersect the filter geometry will be returned.</p> <p>Currently this test is may be inaccurately implemented, but it is guaranteed that all features who's envelope (as returned by <a class="el" href="classOGRGeometry.html#aa3d42b06ae6f7bbef6d1a2886da8d398" title="Computes and returns the bounding envelope for this geometry in the passed psEnvelope structure...">OGRGeometry::getEnvelope()</a>) overlaps the envelope of the spatial filter will be returned. This can result in more shapes being returned that should strictly be the case.</p> <p>This method makes an internal copy of the passed geometry. The passed geometry remains the responsibility of the caller, and may be safely destroyed.</p> <p>For the time being the passed filter geometry should be in the same SRS as the layer (as returned by <a class="el" href="classOGRLayer.html#a75c06b4993f8eb76b569f37365cd19ab" title="Fetch the spatial reference system for this layer. ">OGRLayer::GetSpatialRef()</a>). In the future this may be generalized.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a678d1735bc82533614ac005691d1138c" title="Set a new spatial filter. ">OGR_L_SetSpatialFilter()</a>.</p> <dl class="params"><dt>Parameters</dt><dd> <table class="params"> <tr><td class="paramname">poFilter</td><td>the geometry to use as a filtering region. NULL may be passed indicating that the current spatial filter should be cleared, but no new one instituted. </td></tr> </table> </dd> </dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#a0b4ab45cf97cbc470f0d60474d3e4169">OGRLayer</a>.</p> <p>Referenced by <a class="el" href="classOGRUnionLayer.html#a58427b11107fee76162055092e2364d2">GetFeature()</a>.</p> </div> </div> <a class="anchor" id="a2ece59929973a6f19a95443e45ffccad"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">void OGRUnionLayer::SetSpatialFilter </td> <td>(</td> <td class="paramtype">int </td> <td class="paramname"><em>iGeomField</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype"><a class="el" href="classOGRGeometry.html">OGRGeometry</a> * </td> <td class="paramname"><em>poFilter</em> </td> </tr> <tr> <td></td> <td>)</td> <td></td><td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Set a new spatial filter. </p> <p>This method set the geometry to be used as a spatial filter when fetching features via the <a class="el" href="classOGRUnionLayer.html#a1ff231230bc51b63952c49fbf565d2b8" title="Fetch the next available feature from this layer. ">GetNextFeature()</a> method. Only features that geometrically intersect the filter geometry will be returned.</p> <p>Currently this test is may be inaccurately implemented, but it is guaranteed that all features who's envelope (as returned by <a class="el" href="classOGRGeometry.html#aa3d42b06ae6f7bbef6d1a2886da8d398" title="Computes and returns the bounding envelope for this geometry in the passed psEnvelope structure...">OGRGeometry::getEnvelope()</a>) overlaps the envelope of the spatial filter will be returned. This can result in more shapes being returned that should strictly be the case.</p> <p>This method makes an internal copy of the passed geometry. The passed geometry remains the responsibility of the caller, and may be safely destroyed.</p> <p>For the time being the passed filter geometry should be in the same SRS as the geometry field definition it corresponds to (as returned by <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9" title="Fetch the schema information for this layer. ">GetLayerDefn()</a>->GetGeomFieldDefn(iGeomField)-><a class="el" href="classOGRUnionLayer.html#a8223e23c723151ef11fba997ab4fc605" title="Fetch the spatial reference system for this layer. ">GetSpatialRef()</a>). In the future this may be generalized.</p> <p>Note that only the last spatial filter set is applied, even if several successive calls are done with different iGeomField values.</p> <p>Note to driver implementators: if you implement <a class="el" href="classOGRUnionLayer.html#a2ece59929973a6f19a95443e45ffccad" title="Set a new spatial filter. ">SetSpatialFilter(int,OGRGeometry*)</a>, you must also implement <a class="el" href="classOGRUnionLayer.html#a194555741a74ee0e61c92875683cce7f" title="Set a new spatial filter. ">SetSpatialFilter(OGRGeometry*)</a> to make it call SetSpatialFilter(0,OGRGeometry*).</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a00c8a1a968542d389f86ed1b4edd5823" title="Set a new spatial filter. ">OGR_L_SetSpatialFilterEx()</a>.</p> <dl class="params"><dt>Parameters</dt><dd> <table class="params"> <tr><td class="paramname">iGeomField</td><td>index of the geometry field on which the spatial filter operates. </td></tr> <tr><td class="paramname">poFilter</td><td>the geometry to use as a filtering region. NULL may be passed indicating that the current spatial filter should be cleared, but no new one instituted.</td></tr> </table> </dd> </dl> <dl class="section since"><dt>Since</dt><dd>GDAL 1.11 </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#aebac60fb86ee178be016655532070ee3">OGRLayer</a>.</p> <p>References <a class="el" href="cpl__error_8h.html#aad2b98dd58e4de706a245faddac90403">CPLError()</a>, <a class="el" href="classOGRUnionLayer.html#a4c680d7e5c02454ea7361f341d6d54e9">GetLayerDefn()</a>, and <a class="el" href="classOGRUnionLayer.html#a20c1d59b04f816722d0d6f865f079273">ResetReading()</a>.</p> </div> </div> <a class="anchor" id="a2504c28d8bb046a55c198dbdc58e99bb"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">OGRErr OGRUnionLayer::SyncToDisk </td> <td>(</td> <td class="paramname"></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Flush pending changes to disk. </p> <p>This call is intended to force the layer to flush any pending writes to disk, and leave the disk file in a consistent state. It would not normally have any effect on read-only datasources.</p> <p>Some layers do not implement this method, and will still return OGRERR_NONE. The default implementation just returns OGRERR_NONE. An error is only returned if an error occurs while attempting to flush to disk.</p> <p>In any event, you should always close any opened datasource with <a class="el" href="classOGRDataSource.html#a77841576d07b24a01208e4125ccb40a5" title="Closes opened datasource and releases allocated resources. ">OGRDataSource::DestroyDataSource()</a> that will ensure all data is correctly flushed.</p> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a9d845a6cf6652756925530418905471a" title="Flush pending changes to disk. ">OGR_L_SyncToDisk()</a>.</p> <dl class="section return"><dt>Returns</dt><dd>OGRERR_NONE if no error occurs (even if nothing is done) or an error code. </dd></dl> <p>Reimplemented from <a class="el" href="classOGRLayer.html#aebb07284c734e485d8611b7c8599254f">OGRLayer</a>.</p> <p>References <a class="el" href="classOGRLayer.html#aebb07284c734e485d8611b7c8599254f">OGRLayer::SyncToDisk()</a>.</p> </div> </div> <a class="anchor" id="a6ba10280ddeda91a8ec0efc29e9ef7d6"></a> <div class="memitem"> <div class="memproto"> <table class="mlabels"> <tr> <td class="mlabels-left"> <table class="memname"> <tr> <td class="memname">int OGRUnionLayer::TestCapability </td> <td>(</td> <td class="paramtype">const char * </td> <td class="paramname"><em>pszCap</em></td><td>)</td> <td></td> </tr> </table> </td> <td class="mlabels-right"> <span class="mlabels"><span class="mlabel">virtual</span></span> </td> </tr> </table> </div><div class="memdoc"> <p>Test if this layer supported the named capability. </p> <p>The capability codes that can be tested are represented as strings, but #defined constants exists to ensure correct spelling. Specific layer types may implement class specific capabilities, but this can't generally be discovered by the caller. </p> <ul> <li> <p class="startli"><b>OLCRandomRead</b> / "RandomRead": TRUE if the <a class="el" href="classOGRUnionLayer.html#a58427b11107fee76162055092e2364d2" title="Fetch a feature by its identifier. ">GetFeature()</a> method is implemented in an optimized way for this layer, as opposed to the default implementation using <a class="el" href="classOGRUnionLayer.html#a20c1d59b04f816722d0d6f865f079273" title="Reset feature reading to start on the first feature. ">ResetReading()</a> and <a class="el" href="classOGRUnionLayer.html#a1ff231230bc51b63952c49fbf565d2b8" title="Fetch the next available feature from this layer. ">GetNextFeature()</a> to find the requested feature id.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCSequentialWrite</b> / "SequentialWrite": TRUE if the <a class="el" href="classOGRUnionLayer.html#a094a2f13809f0b2eaabbc572ddfc19ed" title="Create and write a new feature within a layer. ">CreateFeature()</a> method works for this layer. Note this means that this particular layer is writable. The same <a class="el" href="classOGRLayer.html">OGRLayer</a> class may returned FALSE for other layer instances that are effectively read-only.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCRandomWrite</b> / "RandomWrite": TRUE if the <a class="el" href="classOGRUnionLayer.html#ab44d7c6a95d8d6a73f906f60760c0c56" title="Rewrite an existing feature. ">SetFeature()</a> method is operational on this layer. Note this means that this particular layer is writable. The same <a class="el" href="classOGRLayer.html">OGRLayer</a> class may returned FALSE for other layer instances that are effectively read-only.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCFastSpatialFilter</b> / "FastSpatialFilter": TRUE if this layer implements spatial filtering efficiently. Layers that effectively read all features, and test them with the <a class="el" href="classOGRFeature.html">OGRFeature</a> intersection methods should return FALSE. This can be used as a clue by the application whether it should build and maintain its own spatial index for features in this layer.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCFastFeatureCount</b> / "FastFeatureCount": TRUE if this layer can return a feature count (via <a class="el" href="classOGRUnionLayer.html#a6f9c4f51181cb7db75b08a6b81182e67" title="Fetch the feature count in this layer. ">GetFeatureCount()</a>) efficiently ... ie. without counting the features. In some cases this will return TRUE until a spatial filter is installed after which it will return FALSE.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCFastGetExtent</b> / "FastGetExtent": TRUE if this layer can return its data extent (via <a class="el" href="classOGRUnionLayer.html#a36e1634fb7f68fae343179a6007960c4" title="Fetch the extent of this layer, on the specified geometry field. ">GetExtent()</a>) efficiently ... ie. without scanning all the features. In some cases this will return TRUE until a spatial filter is installed after which it will return FALSE.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCFastSetNextByIndex</b> / "FastSetNextByIndex": TRUE if this layer can perform the <a class="el" href="classOGRLayer.html#ae3b6234d6077a18a19eddaf7e75ff5e1" title="Move read cursor to the nIndex'th feature in the current resultset. ">SetNextByIndex()</a> call efficiently, otherwise FALSE.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCCreateField</b> / "CreateField": TRUE if this layer can create new fields on the current layer using <a class="el" href="classOGRLayer.html#a00b1376a1eabb1298ef278f92f6d84be" title="Create a new field on a layer. ">CreateField()</a>, otherwise FALSE.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCCreateGeomField</b> / "CreateGeomField": (GDAL >= 1.11) TRUE if this layer can create new geometry fields on the current layer using <a class="el" href="classOGRLayer.html#af3c68cad279ad80a476c6fb307cf5e48" title="Create a new geometry field on a layer. ">CreateGeomField()</a>, otherwise FALSE.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCDeleteField</b> / "DeleteField": TRUE if this layer can delete existing fields on the current layer using <a class="el" href="classOGRLayer.html#aaebe7c671dca995549543eecf0f7a76a" title="Delete an existing field on a layer. ">DeleteField()</a>, otherwise FALSE.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCReorderFields</b> / "ReorderFields": TRUE if this layer can reorder existing fields on the current layer using <a class="el" href="classOGRLayer.html#ab4c02b991bfa78552eeb0cbcdcf1aed8" title="Reorder an existing field on a layer. ">ReorderField()</a> or <a class="el" href="classOGRLayer.html#aebd364a150d91f8d65d967646e0f92d3" title="Reorder all the fields of a layer. ">ReorderFields()</a>, otherwise FALSE.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCAlterFieldDefn</b> / "AlterFieldDefn": TRUE if this layer can alter the definition of an existing field on the current layer using <a class="el" href="classOGRLayer.html#a71e69a665e93001d48a4339695f33c1a" title="Alter the definition of an existing field on a layer. ">AlterFieldDefn()</a>, otherwise FALSE.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCDeleteFeature</b> / "DeleteFeature": TRUE if the <a class="el" href="classOGRLayer.html#a7e3d454d54a615a1b4359628bb6e7674" title="Delete feature from layer. ">DeleteFeature()</a> method is supported on this layer, otherwise FALSE.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCStringsAsUTF8</b> / "StringsAsUTF8": TRUE if values of OFTString fields are assured to be in UTF-8 format. If FALSE the encoding of fields is uncertain, though it might still be UTF-8.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCTransactions</b> / "Transactions": TRUE if the StartTransaction(), CommitTransaction() and RollbackTransaction() methods work in a meaningful way, otherwise FALSE.</p> <p></p> <p class="endli"></p> </li> <li> <p class="startli"><b>OLCIgnoreFields</b> / "IgnoreFields": TRUE if fields, geometry and style will be omitted when fetching features as set by <a class="el" href="classOGRUnionLayer.html#a81737b724f0c7c0f81d593cec662bb08" title="Set which fields can be omitted when retrieving features from the layer. ">SetIgnoredFields()</a> method.</p> <p></p> <p></p> <p class="endli"></p> </li> </ul> <p>This method is the same as the C function <a class="el" href="ogr__api_8h.html#a480adc8b839b04597f49583371d366fd" title="Test if this layer supported the named capability. ">OGR_L_TestCapability()</a>.</p> <dl class="params"><dt>Parameters</dt><dd> <table class="params"> <tr><td class="paramname">pszCap</td><td>the name of the capability to test.</td></tr> </table> </dd> </dl> <dl class="section return"><dt>Returns</dt><dd>TRUE if the layer has the requested capability, or FALSE otherwise. OGRLayers will return FALSE for any unrecognised capabilities.</dd></dl> <p>Implements <a class="el" href="classOGRLayer.html#aeedbda1a62f9b89b8e5f24332cf22286">OGRLayer</a>.</p> </div> </div> <hr/>The documentation for this class was generated from the following files:<ul> <li><a class="el" href="ogrunionlayer_8h_source.html">ogrunionlayer.h</a></li> <li>ogrunionlayer.cpp</li> </ul> </div><!-- contents --> <hr> Generated for GDAL by <a href="http://www.doxygen.org/index.html"><img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.8.5. </body> </html>