adding a feature.modified property, making the ModifyFeature control set it and the WFST format check for it so only modified attributes and a modified geometry need to be included in an Update transaction. r=bartvde (closes #3400)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@12149 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Control/ModifyFeature.js

@@ -368,6 +368,11 @@ OpenLayers.Control.ModifyFeature = OpenLayers.Class(OpenLayers.Control, {
             this.dragControl.activate();
             this.onModificationStart(this.feature);
         }
+        // keep track of geometry modifications
+        var modified = feature.modified;
+        if (feature.geometry && !(modified && modified.geometry)) {
+            this._originalGeometry = feature.geometry.clone();
+        }
     },
 
     /**
@@ -539,6 +544,13 @@ OpenLayers.Control.ModifyFeature = OpenLayers.Class(OpenLayers.Control, {
         if(this.feature.state != OpenLayers.State.INSERT &&
            this.feature.state != OpenLayers.State.DELETE) {
             this.feature.state = OpenLayers.State.UPDATE;
+            if (this.modified && this._originalGeometry) {
+                var feature = this.feature;
+                feature.modified = OpenLayers.Util.extend(feature.modified, {
+                    geometry: this._originalGeometry
+                });
+                delete this._originalGeometry;
+            }
         }
     },
     

lib/OpenLayers/Feature/Vector.js

@@ -81,6 +81,42 @@ OpenLayers.Feature.Vector = OpenLayers.Class(OpenLayers.Feature, {
      * {String} rendering intent currently being used
      */
     renderIntent: "default",
+    
+    /**
+     * APIProperty: modified
+     * {Object} An object with the originals of the geometry and attributes of
+     * the feature, if they were changed. Currently this property is only read
+     * by <OpenLayers.Format.WFST.v1>, and written by
+     * <OpenLayers.Control.ModifyFeature>, which sets the geometry property.
+     * Applications can set the originals of modified attributes in the
+     * attributes property. Note that applications have to check if this
+     * object and the attributes property is already created before using it.
+     * After a change made with ModifyFeature, this object could look like
+     *
+     * (code)
+     * {
+     *     geometry: >Object
+     * }
+     * (end)
+     *
+     * When an application has made changes to feature attributes, it could
+     * have set the attributes to something like this:
+     *
+     * (code)
+     * {
+     *     attributes: {
+     *         myAttribute: "original"
+     *     }
+     * }
+     * (end)
+     *
+     * Note that <OpenLayers.Format.WFST.v1> only checks for truthy values in
+     * *modified.geometry* and the attribute names in *modified.attributes*,
+     * but it is recommended to set the original values (and not just true) as
+     * attribute value, so applications could use this information to undo
+     * changes.
+     */
+    modified: null,
 
     /** 
      * Constructor: OpenLayers.Feature.Vector

lib/OpenLayers/Format/WFST/v1.js

@@ -172,9 +172,24 @@ OpenLayers.Format.WFST.v1 = OpenLayers.Class(OpenLayers.Format.XML, {
      *     type - insert, update, or delete.
      *
      * Parameters:
-     * features - {Array(<OpenLayers.Feature.Vector>)} A list of features.
+     * features - {Array(<OpenLayers.Feature.Vector>)} A list of features. See
+     *     below for a more detailed description of the influence of the
+     *     feature's *modified* property.
      * options - {Object}
      *
+     * feature.modified rules:
+     * If a feature has a modified property set, the following checks will be
+     * made before a feature's geometry or attribute is included in an Update
+     * transaction:
+     * - *modified* is not set at all: The geometry and all attributes will be
+     *     included.
+     * - *modified.geometry* is truthy: The geometry will be
+     *     included. If *modified.attributes* is not set, all attributes will
+     *     be included.
+     * - *modified.attributes* is set: Only the attributes with a truthy value
+     *     in *modified.attributes* will be included. If *modified.geometry*
+     *     is not set, the geometry will not be included.
+     *
      * Returns:
      * {String} A serialized WFS transaction.
      */
@@ -276,7 +291,8 @@ OpenLayers.Format.WFST.v1 = OpenLayers.Class(OpenLayers.Format.XML, {
                 }
                 
                 // add in geometry
-                if (this.geometryName !== null) {
+                var modified = feature.modified;
+                if (this.geometryName !== null && (!modified || modified.geometry)) {
                     this.srsName = this.getSrsName(feature);
                     this.writeNode(
                         "Property", {name: this.geometryName, value: feature.geometry}, node
@@ -285,7 +301,9 @@ OpenLayers.Format.WFST.v1 = OpenLayers.Class(OpenLayers.Format.XML, {
         
                 // add in attributes
                 for(var key in feature.attributes) {
-                    if(feature.attributes[key] !== undefined) {
+                    if(feature.attributes[key] !== undefined &&
+                                (!modified || !modified.attributes ||
+                                (modified.attributes && modified.attributes[key]))) {
                         this.writeNode(
                             "Property", {name: key, value: feature.attributes[key]}, node
                         );