auto-configure featureType and featureNS. p=bartvde (closes #3367)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@12110 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Format/GML/Base.js

@@ -101,6 +101,18 @@ OpenLayers.Format.GML.Base = OpenLayers.Class(OpenLayers.Format.XML, {
      *     of featuretypes.
      */
     singleFeatureType: null,
+    
+    /**
+     * Property: autoConfig
+     * {Boolean} Indicates if the format was configured without a <featureNS>,
+     * but auto-configured <featureNS> and <featureType> during read.
+     * Subclasses making use of <featureType> auto-configuration should make
+     * the first call to the <readNode> method (usually in the read method)
+     * with true as 3rd argument, so the auto-configured featureType can be
+     * reset and the format can be reused for subsequent reads with data from
+     * different featureTypes. Set to false after read if you want to keep the
+     * auto-configured values.
+     */
 
     /**
      * Property: regExes
@@ -110,7 +122,8 @@ OpenLayers.Format.GML.Base = OpenLayers.Class(OpenLayers.Format.XML, {
         trimSpace: (/^\s*|\s*$/g),
         removeSpace: (/\s*/g),
         splitSpace: (/\s+/),
-        trimComma: (/\s*,\s*/g)
+        trimComma: (/\s*,\s*/g),
+        featureMember: (/^(.*:)?featureMembers?$/)
     },
 
     /**
@@ -125,9 +138,9 @@ OpenLayers.Format.GML.Base = OpenLayers.Class(OpenLayers.Format.XML, {
      *
      * Valid options properties:
      * featureType - {Array(String) or String} Local (without prefix) feature 
-     *     typeName(s) (required).
-     * featureNS - {String} Feature namespace (required).
-     * geometryName - {String} Geometry element name.
+     *     typeName(s) (required for write).
+     * featureNS - {String} Feature namespace (required for write).
+     * geometryName - {String} Geometry element name (required for write).
      */
     initialize: function(options) {
         OpenLayers.Format.XML.prototype.initialize.apply(this, [options]);
@@ -156,7 +169,7 @@ OpenLayers.Format.GML.Base = OpenLayers.Class(OpenLayers.Format.XML, {
             data = data.documentElement;
         }
         var features = [];
-        this.readNode(data, {features: features});
+        this.readNode(data, {features: features}, true);
         if(features.length == 0) {
             // look for gml:featureMember elements
             var elements = this.getElementsByTagNameNS(
@@ -164,7 +177,7 @@ OpenLayers.Format.GML.Base = OpenLayers.Class(OpenLayers.Format.XML, {
             );
             if(elements.length) {
                 for(var i=0, len=elements.length; i<len; ++i) {
-                    this.readNode(elements[i], {features: features});
+                    this.readNode(elements[i], {features: features}, true);
                 }
             } else {
                 // look for gml:featureMembers elements (this is v3, but does no harm here)
@@ -173,13 +186,50 @@ OpenLayers.Format.GML.Base = OpenLayers.Class(OpenLayers.Format.XML, {
                 );
                 if(elements.length) {
                     // there can be only one
-                    this.readNode(elements[0], {features: features});
+                    this.readNode(elements[0], {features: features}, true);
                 }
             }
         }
         return features;
     },
     
+    /**
+     * Method: readNode
+     * Shorthand for applying one of the named readers given the node
+     *     namespace and local name.  Readers take two args (node, obj) and
+     *     generally extend or modify the second.
+     *
+     * Parameters:
+     * node - {DOMElement} The node to be read (required).
+     * obj - {Object} The object to be modified (optional).
+     * first - {Boolean} Should be set to true for the first node read. This
+     *     is usually the readNode call in the read method. Without this being
+     *     set, auto-configured properties will stick on subsequent reads.
+     *
+     * Returns:
+     * {Object} The input object, modified (or a new one if none was provided).
+     */
+    readNode: function(node, obj, first) {
+        // on subsequent calls of format.read(), we want to reset auto-
+        // configured properties and auto-configure again.
+        if (first === true && this.autoConfig === true) {
+            this.featureType = null;
+            delete this.namespaceAlias[this.featureNS];
+            delete this.namespaces["feature"];
+            this.featureNS = null;
+        }
+        // featureType auto-configuration
+        if (!this.featureNS && (!(node.prefix in this.namespaces) &&
+                node.parentNode.namespaceURI == this.namespaces["gml"] &&
+                this.regExes.featureMember.test(node.parentNode.nodeName))) {
+            this.featureType = node.nodeName.split(":").pop();
+            this.setNamespace("feature", node.namespaceURI);
+            this.featureNS = node.namespaceURI;
+            this.autoConfig = true;
+        }
+        return OpenLayers.Format.XML.prototype.readNode.apply(this, arguments);
+    },
+
     /**
      * Property: readers
      * Contains public functions, grouped by namespace prefix, that will