Add support to Cross-Layer Filtering (#1262)

* Add support to Cross-Layer Filtering

Added to Filter Utils the possibility to parse cross layer filtering

* add doc and test

web/client/utils/FilterUtils.jsx

@@ -49,7 +49,7 @@ const FilterUtils = {
         "ogc": {startTag: "<ogc:PropertyName>", endTag: "</ogc:PropertyName>"},
         "fes": {startTag: "<fes:ValueReference>", endTag: "</fes:ValueReference>"}
     },
-    toOGCFilter: function(ftName, json, version, sortOptions = null, hits = false, format = null) {
+    toOGCFilter: function(ftName, json, version, sortOptions = null, hits = false, format = null, propertyNames = null) {
         try {
             this.objFilter = (json instanceof Object) ? json : JSON.parse(json);
         } catch(e) {
@@ -87,6 +87,14 @@ const FilterUtils = {
             spatialFilter = this.processOGCSpatialFilter(versionOGC);
             filters.push(spatialFilter);
         }
+        if (this.objFilter.crossLayerFilter) {
+            let crossLayerFilter = this.objFilter.crossLayerFilter;
+            if (Array.isArray()) {
+                crossLayerFilter.forEach( f => filters.push(this.processOGCCrossLayerFilter(f)));
+            } else {
+                filters.push(this.processOGCCrossLayerFilter(crossLayerFilter));
+            }
+        }
 
         let filter = "<" + this.nsplaceholder + ":Filter>";
 
@@ -104,7 +112,12 @@ const FilterUtils = {
 
         ogcFilter += '<wfs:Query ' + (versionOGC === "2.0" ? "typeNames" : "typeName") + '="' + ftName + '" srsName="EPSG:4326">';
         ogcFilter += filter;
-
+        if (propertyNames) {
+            ogcFilter += propertyNames.map( name => (
+                this.propertyTagReference[this.nsplaceholder].startTag +
+                name +
+                this.propertyTagReference[this.nsplaceholder].endTag )).join("");
+        }
         if (sortOptions && sortOptions.sortBy && sortOptions.sortOrder) {
             ogcFilter +=
                 "<" + this.nsplaceholder + ":SortBy>" +
@@ -475,6 +488,54 @@ const FilterUtils = {
         ogc += this.ogcSpatialOperator[this.objFilter.spatialField.operation].endTag;
         return ogc;
     },
+    /**
+    *  processOGCCrossLayerFilter(object)
+    *  object should be in this form :
+    *    {
+    *    operation: "FILTER_OPERATION_TO_DO_WITH_GEOMETRY",
+    *       attribute: "GEOMETRY_NAME_OF_THE_FEATURE_TYPE_TO_FILTER",
+    *       collectGeometries: {queryCollection: {
+    *           typeName: "TYPE_NAME_TO_QUERY",
+    *           geometryName: "GEOMETRY_NAME_OF_THE_FEATURE_TYPE_TO_QUERY",
+    *           cqlFilter: "CQL_FITER_TO_APPLY_TO_THE_FEATURE_TYPE"
+    *       }
+    * }}
+    * Example: if I want to filter the featureType "roads", with the geometryName = "roads_geom"
+    * that intersect the polygons from the featureType "regions, with geometryName "regions_geom"
+    * where the attribute "area" of the region is >= 10 You will have the following
+    *    {
+    *   operation: "INTERSECTS"
+    *   attribute: "roads_geom",
+    *    collectGeometries: {queryCollection: {
+    *       typeName: "regions",
+    *       geometryName: "regions_geom",
+    *       cqlFilter: "area > 10"
+    *   }}
+    *   }
+    */
+    processOGCCrossLayerFilter: function(crossLayerFilter) {
+        let ogc = this.ogcSpatialOperator[crossLayerFilter.operation].startTag;
+        ogc +=
+            this.propertyTagReference[this.nsplaceholder].startTag +
+                crossLayerFilter.attribute +
+            this.propertyTagReference[this.nsplaceholder].endTag;
+        // only collectGeometries is supported now
+        if (crossLayerFilter.collectGeometries) {
+            ogc += `<ogc:Function name="collectGeometries">` +
+             `<ogc:Function name="queryCollection">` +
+               `<ogc:Literal>${crossLayerFilter.collectGeometries.queryCollection.typeName}</ogc:Literal>` +
+               `<ogc:Literal>${crossLayerFilter.collectGeometries.queryCollection.geometryName}</ogc:Literal>` +
+               `<ogc:Literal>${crossLayerFilter.collectGeometries.queryCollection.cqlFilter}</ogc:Literal>` +
+             `</ogc:Function>` +
+         `</ogc:Function>`;
+        }
+        if (crossLayerFilter.operation === "DWITHIN") {
+            ogc += '<' + this.nsplaceholder + ':Distance units="m">' + (crossLayerFilter.distance || 0) + '</' + this.nsplaceholder + ':Distance>';
+        }
+
+        ogc += this.ogcSpatialOperator[crossLayerFilter.operation].endTag;
+        return ogc;
+    },
     getGmlPointElement: function(coordinates, srsName, version) {
         let gmlPoint = '<gml:Point srsDimension="2"';
 

web/client/utils/__tests__/FilterUtils-test.js

@@ -461,4 +461,32 @@ describe('FilterUtils', () => {
         let filter = FilterUtils.toCQLFilter(filterObj);
         expect(filter).toEqual(expected);
     });
+    it('Check CrossLayerFilter segment generation', () => {
+        let crossLayerFilterObj = {
+           operation: "INTERSECTS",
+           attribute: "roads_geom",
+           collectGeometries: {queryCollection: {
+               typeName: "regions",
+               geometryName: "regions_geom",
+               cqlFilter: "area > 10"
+           }}
+        };
+        let expected = "<ogc:Intersects>"
+         + '<ogc:PropertyName>roads_geom</ogc:PropertyName>'
+         + '<ogc:Function name="collectGeometries">'
+         + '<ogc:Function name="queryCollection">'
+         + '<ogc:Literal>regions</ogc:Literal>'
+         + '<ogc:Literal>regions_geom</ogc:Literal>'
+         + '<ogc:Literal>area > 10</ogc:Literal>'
+         + '</ogc:Function></ogc:Function>'
+         + "</ogc:Intersects>";
+
+        // this is a workarround for this issue : https://github.com/geosolutions-it/MapStore2/issues/1263
+        // please remove when fixed
+        FilterUtils.nsplaceholder = "ogc";
+        FilterUtils.setOperatorsPlaceholders("{namespace}", "ogc");
+
+        let filter = FilterUtils.processOGCCrossLayerFilter(crossLayerFilterObj);
+        expect(filter).toEqual(expected);
+    });
 });