Using mapowscommon.c

mapowscommon implements the OGC OWS Common Specification

• version 1.0.0
• OGC document: OGC 05-008

The library uses libxml2 (​http://www.xmlsoft.org/) to create XML objects.

The library uses the tree and parser modules of libxml2.

The library returns xmlNodePtr objects to the calling code.

With the exception of msOWSCommonExceptionReport, ALL functions return an XML chunk. It is the responsibility of the calling code to setup the root element with correct namespace decls and schema pointers

msOWSCommonExceptionReport returns an entire, complete and valid XML document, as it is the only XML in OWS Common which is designed to be implemented standalone. In this case, the calling code must instantiate an ​xmlNewDoc object.

EXAMPLE 1: create a service Exception

#include "libxml/parser.h"
#include "libxml/tree.h"

#include "mapowscommon.h"

static int msSOSException(mapObj *map, char *locator, char *exceptionCode) {
  xmlDocPtr  psDoc      = NULL;
  xmlNodePtr psRootNode = NULL;
  xmlChar    *buffer    = NULL;
  int size = 0;

  /* create XML document object */
  psDoc = xmlNewDoc(BAD_CAST "1.0");

  /* generate a service exception object */
  psRootNode = msOWSCommonExceptionReport(msEncodeHTMLEntities(msOWSGetSchemasLocation(map)), pszSOSVersion, msOWSGetLanguage(map, "exception"), exceptionCode, locator, msEncodeHTMLEntities(msGetErrorString("\n")));

  /* set the root element of the document */
  xmlDocSetRootElement(psDoc, psRootNode);

  /* set the namespace of the document */
  xmlSetNs(psRootNode,  xmlNewNs(psRootNode, BAD_CAST MS_OWSCOMMON_OWS_NAMESPACE_URI, BAD_CAST MS_OWSCOMMON_OWS_NAMESPACE_PREFIX));

  msIO_printf("Content-type: text/xml%c%c",10,10);

  /* dump the libxml2 object to a string for output */
  xmlDocDumpFormatMemoryEnc(psDoc, &buffer, &size, "ISO-8859-1", 1);

  msIO_printf("%s", buffer);

  /*free buffer and the document */
  xmlFree(buffer);
  xmlFreeDoc(psDoc);

  /* clear error since we have already reported it */
  msResetErrorList();

  return MS_FAILURE;
}

See mapogcsos.c:msSOSException for an example in the codebase

Example 2: integrate OWS Common info as part of an existing document:

#include "libxml/parser.h"
#include "libxml/tree.h"

#include "mapowscommon.h"

static int msPrintBoundingBox() {
  xmlDocPtr  psDoc      = NULL;
  xmlNodePtr psRootNode = NULL;
  xmlNodePtr psNode     = NULL;
  xmlChar    *buffer    = NULL;
  int size = 0;

  /* create XML document object */
  psDoc = xmlNewDoc(BAD_CAST "1.0");

  /* generate the root node */
  psRootNode = xmlNewNode(NULL, BAD_CAST "My_Root_Node");

  /* set the root element of the document */
  xmlDocSetRootElement(psDoc, psRootNode);

  /* set the namespace of the document */
  xmlSetNs(psRootNode,  xmlNewNs(psRootNode, BAD_CAST MS_OWSCOMMON_OWS_NAMESPACE_URI, BAD_CAST MS_OWSCOMMON_OWS_NAMESPACE_PREFIX));

  psNode = msOWSCommonWGS84BoundingBox(2, -180.0, -90.0, 180, 90);

  msIO_printf("Content-type: text/xml%c%c",10,10);

  /* dump the libxml2 object to a string for output */
  xmlDocDumpFormatMemoryEnc(psDoc, &buffer, &size, "ISO-8859-1", 1);

  msIO_printf("%s", buffer);

  /*free buffer and the document */
  xmlFree(buffer);
  xmlFreeDoc(psDoc);
}

See mapogcsos.c:msSOSGetCapabilities for an example in the codebase