Adding support for TextSymbolizer writing in the SLD format. Thanks to Bart for the original patch. This provides basic expression handling for text labels. Read support later. r=ahocevar (closes #1542)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@7333 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Format/SLD/v1.js

@@ -425,7 +425,9 @@ OpenLayers.Format.SLD.v1 = OpenLayers.Class(OpenLayers.Format.XML, {
         "stroke-width": "strokeWidth",
         "stroke-linecap": "strokeLinecap",
         "fill": "fillColor",
-        "fill-opacity": "fillOpacity"
+        "fill-opacity": "fillOpacity",
+        "font-family": "fontFamily",
+        "font-size": "fontSize"
     },
     
     /**
@@ -732,6 +734,68 @@ OpenLayers.Format.SLD.v1 = OpenLayers.Class(OpenLayers.Format.XML, {
                     value: obj.symbolizer[obj.key]
                 });
             },
+            "TextSymbolizer": function(symbolizer) {
+                var node = this.createElementNSPlus("TextSymbolizer");
+                // add in optional Label
+                if(symbolizer.label != null) {
+                    this.writeNode(node, "Label", symbolizer.label);
+                }
+                // add in optional Font
+                if(symbolizer.fontFamily != null ||
+                   symbolizer.fontSize != null) {
+                    this.writeNode(node, "Font", symbolizer);
+                }
+                // add in optional Fill
+                if(symbolizer.fillColor != null ||
+                   symbolizer.fillOpacity != null) {
+                    this.writeNode(node, "Fill", symbolizer);
+                }
+                return node;
+            },
+            "Font": function(symbolizer) {
+                var node = this.createElementNSPlus("Font");
+                // add in CssParameters
+                if(symbolizer.fontFamily) {
+                    this.writeNode(
+                        node, "CssParameter",
+                        {symbolizer: symbolizer, key: "fontFamily"}
+                    );
+                }
+                if(symbolizer.fontSize) {
+                    this.writeNode(
+                        node, "CssParameter",
+                        {symbolizer: symbolizer, key: "fontSize"}
+                    );
+                }
+                return node;
+            },
+            "Label": function(label) {
+                // only the simplest of ogc:expression handled
+                // {label: "some text and a ${propertyName}"}
+                var node = this.createElementNSPlus("Label");
+                var tokens = label.split("${");
+                node.appendChild(this.createTextNode(tokens[0]));
+                var item, last;
+                for(var i=1; i<tokens.length; i++) {
+                    item = tokens[i];
+                    last = item.indexOf("}"); 
+                    if(last > 0) {
+                        this.writeNode(
+                            node, "ogc:PropertyName",
+                            {property: item.substring(0, last)}
+                        );
+                        node.appendChild(
+                            this.createTextNode(item.substring(++last))
+                        );
+                    } else {
+                        // no ending }, so this is a literal ${
+                        node.appendChild(
+                            this.createTextNode("${" + item)
+                        );
+                    }
+                }
+                return node;
+            },
             "PolygonSymbolizer": function(symbolizer) {
                 var node = this.createElementNSPlus("PolygonSymbolizer");
                 this.writeNode(node, "Fill", symbolizer);

lib/OpenLayers/Style.js

@@ -353,4 +353,4 @@ OpenLayers.Style.createLiteral = function(value, context, feature) {
  * {Array} prefixes of the sld symbolizers. These are the
  * same as the main geometry types
  */
-OpenLayers.Style.SYMBOLIZER_PREFIXES = ['Point', 'Line', 'Polygon'];
+OpenLayers.Style.SYMBOLIZER_PREFIXES = ['Point', 'Line', 'Polygon', 'Text'];

tests/Format/SLD/v1_0_0.html

@@ -150,6 +150,42 @@
         
     }
     
+    function test_writeTextSymbolizer(t) {
+        t.plan(1);
+        var parser = new OpenLayers.Format.SLD.v1_0_0();
+        var symbolizer = {
+            "Text": {
+                "label": "This is the ${city} in ${state}.",
+                "fontFamily": "Arial",
+                "fontSize": 10,
+                "fillColor": "blue"
+            }
+        };
+        var node = parser.writers["sld"]["TextSymbolizer"].apply(
+            parser, [symbolizer["Text"]]
+        );
+        
+        var expected =
+            '<TextSymbolizer xmlns="http://www.opengis.net/sld">' +
+                '<Label>' +
+                    'This is the ' +
+                    '<ogc:PropertyName xmlns:ogc="http://www.opengis.net/ogc">city</ogc:PropertyName>' +
+                    ' in ' +
+                    '<ogc:PropertyName xmlns:ogc="http://www.opengis.net/ogc">state</ogc:PropertyName>' +
+                    '.' +
+                '</Label>' +
+                '<Font>' +
+                    '<CssParameter name="font-family">Arial</CssParameter>' +
+                    '<CssParameter name="font-size">10</CssParameter>' +
+                '</Font>' +
+                '<Fill>' +
+                    '<CssParameter name="fill">blue</CssParameter>' +
+                '</Fill>' + 
+            '</TextSymbolizer>';
+        
+        t.xml_eq(node, expected, "TextSymbolizer correctly written");
+        
+    }
 
     </script> 
 </head>