WFS: implements SortBy

Author: rouault

mapfile.c

@@ -3805,6 +3805,9 @@ int initLayer(layerObj *layer, mapObj *map)
   layer->utfitemindex = -1;
 
   layer->encoding = NULL;
+  
+  layer->sortBy.nProperties = 0;
+  layer->sortBy.properties = NULL;
 
   return(0);
 }
@@ -3923,6 +3926,10 @@ int freeLayer(layerObj *layer)
 
   freeExpression(&(layer->utfdata));
   msFree(layer->utfitem);
+  
+  for(i=0;i<layer->sortBy.nProperties;i++)
+      msFree(layer->sortBy.properties[i].item);
+  msFree(layer->sortBy.properties);
 
   return MS_SUCCESS;
 }

maplayer.c

@@ -1412,6 +1412,66 @@ int msLayerSupportsPaging(layerObj *layer)
   return MS_FALSE;
 }
 
+/*
+ * msLayerSupportsSorting()
+ *
+ * Returns MS_TRUE if the layer supports sorting/ordering.
+ */
+int msLayerSupportsSorting(layerObj *layer)
+{
+  if (layer &&
+      ((layer->connectiontype == MS_OGR) ||
+       (layer->connectiontype == MS_POSTGIS)) )
+    return MS_TRUE;
+
+  return MS_FALSE;
+}
+
+/*
+ * msLayerSetSort()
+ *
+ * Copy the sortBy clause passed as an argument into the layer sortBy member.
+ */
+void msLayerSetSort(layerObj *layer, const sortByClause* sortBy)
+{
+  int i;
+  for(i=0;i<layer->sortBy.nProperties;i++)
+      msFree(layer->sortBy.properties[i].item);
+  msFree(layer->sortBy.properties);
+
+  layer->sortBy.nProperties = sortBy->nProperties;
+  layer->sortBy.properties = (sortByProperties*) msSmallMalloc(
+                        sortBy->nProperties * sizeof(sortByProperties) );
+  for(i=0;i<layer->sortBy.nProperties;i++) {
+     layer->sortBy.properties[i].item = msStrdup(sortBy->properties[i].item);
+     layer->sortBy.properties[i].sortOrder = sortBy->properties[i].sortOrder;
+  }
+}
+
+/*
+ * msLayerBuildSQLOrderBy()
+ *
+ * Returns the content of a SQL ORDER BY clause from the sortBy member of
+ * the layer. The string does not contain the "ORDER BY" keywords itself.
+ */
+char* msLayerBuildSQLOrderBy(layerObj *layer)
+{
+  char* strOrderBy = NULL;
+  if( layer->sortBy.nProperties > 0 ) {
+    int i;
+    for(i=0;i<layer->sortBy.nProperties;i++) {
+      char* escaped = msLayerEscapePropertyName(layer, layer->sortBy.properties[i].item);
+      if( i > 0 )
+          strOrderBy = msStringConcatenate(strOrderBy, ", ");
+      strOrderBy = msStringConcatenate(strOrderBy, escaped);
+      if( layer->sortBy.properties[i].sortOrder == SORT_DESC )
+          strOrderBy = msStringConcatenate(strOrderBy, " DESC");
+      msFree(escaped);
+    }
+  }
+  return strOrderBy;
+}
+
 int
 msLayerApplyPlainFilterToLayer(FilterEncodingNode *psNode, mapObj *map,
                                int iLayerIndex)

mapogr.cpp

@@ -51,6 +51,7 @@
 
 typedef struct ms_ogr_file_info_t {
   char        *pszFname;
+  char        *pszLayerDef;
   int         nLayerIndex;
   OGRDataSourceH hDS;
   OGRLayerH   hLayer;
@@ -1196,14 +1197,13 @@ msOGRFileOpen(layerObj *layer, const char *connection )
     return NULL;
   }
 
-  CPLFree( pszLayerDef );
-
   /* ------------------------------------------------------------------
    * OK... open succeded... alloc and fill msOGRFileInfo inside layer obj
    * ------------------------------------------------------------------ */
   msOGRFileInfo *psInfo =(msOGRFileInfo*)CPLCalloc(1,sizeof(msOGRFileInfo));
 
   psInfo->pszFname = CPLStrdup(OGR_DS_GetName( hDS ));
+  psInfo->pszLayerDef = pszLayerDef;
   psInfo->nLayerIndex = nLayerIndex;
   psInfo->hDS = hDS;
   psInfo->hLayer = hLayer;
@@ -1247,6 +1247,7 @@ static int msOGRFileClose(layerObj *layer, msOGRFileInfo *psInfo )
             psInfo->pszFname, psInfo->nLayerIndex);
 
   CPLFree(psInfo->pszFname);
+  CPLFree(psInfo->pszLayerDef);
 
   ACQUIRE_OGR_LOCK;
   if (psInfo->hLastFeature)
@@ -1361,6 +1362,53 @@ static int msOGRFileWhichShapes(layerObj *layer, rectObj rect,
     return(MS_FAILURE);
   }
 
+  /* Apply sortBy */
+  if( layer->sortBy.nProperties > 0 ) {
+    char* strOrderBy;
+    char* pszLayerDef = NULL;
+
+    strOrderBy = msLayerBuildSQLOrderBy(layer);
+
+    if( psInfo->nLayerIndex == -1 )
+    {
+        pszLayerDef = msStrdup(psInfo->pszLayerDef);
+        if( strcasestr(psInfo->pszLayerDef, " ORDER BY ") == NULL )
+            pszLayerDef = msStringConcatenate(pszLayerDef, " ORDER BY ");
+        else
+            pszLayerDef = msStringConcatenate(pszLayerDef, ", ");
+    }
+    else
+    {
+        pszLayerDef = msStringConcatenate(pszLayerDef, "SELECT * FROM \"");
+        pszLayerDef = msStringConcatenate(pszLayerDef, OGR_FD_GetName(OGR_L_GetLayerDefn(psInfo->hLayer)));
+        pszLayerDef = msStringConcatenate(pszLayerDef, "\" ORDER BY ");
+    }
+
+    pszLayerDef = msStringConcatenate(pszLayerDef, strOrderBy);
+    msFree(strOrderBy);
+    strOrderBy = NULL;
+
+    if( layer->debug )
+      msDebug("msOGRFileWhichShapes: SQL = %s.\n", pszLayerDef);
+
+    /* If nLayerIndex == -1 then the layer is an SQL result ... free it */
+    if( psInfo->nLayerIndex == -1 )
+        OGR_DS_ReleaseResultSet( psInfo->hDS, psInfo->hLayer );
+    psInfo->nLayerIndex = -1;
+
+    ACQUIRE_OGR_LOCK;
+    psInfo->hLayer = OGR_DS_ExecuteSQL( psInfo->hDS, pszLayerDef, NULL, NULL );
+    msFree(pszLayerDef);
+    RELEASE_OGR_LOCK;
+    if( psInfo->hLayer == NULL ) {
+      msSetError(MS_OGRERR,
+                 "ExecuteSQL(%s) failed.\n%s",
+                 "msOGRFileWhichShapes()",
+                 pszLayerDef, CPLGetLastErrorMsg() );
+      return MS_FAILURE;
+    }
+  }
+
   /* ------------------------------------------------------------------
    * Set Spatial filter... this may result in no features being returned
    * if layer does not overlap current view.

mappostgis.c

@@ -1870,11 +1870,13 @@ char *msPostGISBuildSQLWhere(layerObj *layer, rectObj *rect, long *uid)
   char *strFilter = 0;
   char *strUid = 0;
   char *strWhere = 0;
+  char *strOrderBy = 0;
   char *strLimit = 0;
   char *strOffset = 0;
   size_t strRectLength = 0;
   size_t strFilterLength = 0;
   size_t strUidLength = 0;
+  size_t strOrderByLength = 0;
   size_t strLimitLength = 0;
   size_t strOffsetLength = 0;
   size_t bufferSize = 0;
@@ -1954,8 +1956,17 @@ char *msPostGISBuildSQLWhere(layerObj *layer, rectObj *rect, long *uid)
     strUidLength = strlen(strUid);
   }
 
+  /* Populate strOrderBy, if necessary */
+  if( layer->sortBy.nProperties > 0 ) {
+    char* pszTmp = msLayerBuildSQLOrderBy(layer);
+    strOrderBy = msStringConcatenate(strOrderBy, " ORDER BY ");
+    strOrderBy = msStringConcatenate(strOrderBy, pszTmp);
+    msFree(pszTmp);
+    strOrderByLength = strlen(strOrderBy);
+  }
+
   bufferSize = strRectLength + 5 + strFilterLength + 5 + strUidLength
-               + strLimitLength + strOffsetLength;
+               + strLimitLength + strOffsetLength + strOrderByLength;
   strWhere = (char*)msSmallMalloc(bufferSize);
   *strWhere = '\0';
   if ( strRect ) {
@@ -1979,6 +1990,12 @@ char *msPostGISBuildSQLWhere(layerObj *layer, rectObj *rect, long *uid)
     free(strUid);
     insert_and++;
   }
+
+  if ( strOrderBy ) {
+    strlcat(strWhere, strOrderBy, bufferSize);
+    free(strOrderBy);
+  }
+
   if ( strLimit ) {
     strlcat(strWhere, strLimit, bufferSize);
     free(strLimit);
@@ -2046,6 +2063,7 @@ char *msPostGISBuildSQL(layerObj *layer, rectObj *rect, long *uid)
 
   strSQL = msSmallMalloc(strlen(strSQLTemplate) + strlen(strFrom) + strlen(strItems) + strlen(strWhere));
   sprintf(strSQL, strSQLTemplate, strItems, strFrom, strWhere);
+
   if (strItems) free(strItems);
   if (strFrom) free(strFrom);
   if (strWhere) free(strWhere);

mapserver.h

@@ -1487,7 +1487,24 @@ extern "C" {
      int n_entries;
      scaleTokenEntryObj *tokens;
   } scaleTokenObj;
-  
+
+#ifndef SWIG
+  typedef enum {
+      SORT_ASC,
+      SORT_DESC
+  } sortOrderEnum;
+
+  typedef struct {
+      char* item;
+      sortOrderEnum sortOrder;
+  } sortByProperties;
+
+  typedef struct {
+      int nProperties;
+      sortByProperties* properties;
+  } sortByClause;
+#endif
+
   struct layerObj {
 
     char *classitem; /* .DBF item to be used for symbol lookup */
@@ -1674,6 +1691,10 @@ extern "C" {
     char *utfitem;
     int utfitemindex;
     expressionObj utfdata;
+
+#ifndef SWIG
+    sortByClause sortBy;
+#endif
   };
 
 
@@ -2366,6 +2387,10 @@ void msPopulateTextSymbolForLabelAndString(textSymbolObj *ts, labelObj *l, char
   MS_DLL_EXPORT char *msLayerEscapeSQLParam(layerObj *layer, const char* pszString);
   MS_DLL_EXPORT char *msLayerEscapePropertyName(layerObj *layer, const char* pszString);
 
+  int msLayerSupportsSorting(layerObj *layer);
+  void msLayerSetSort(layerObj *layer, const sortByClause* sortBy);
+  char* msLayerBuildSQLOrderBy(layerObj *layer);
+
   /* These are special because SWF is using these */
   int msOGRLayerNextShape(layerObj *layer, shapeObj *shape);
   int msOGRLayerGetItems(layerObj *layer);