allow protocols to be configured with a default filter, p=aabt, r=me (closes #2292)

git-svn-id: http://svn.openlayers.org/trunk/openlayers@9702 dc9f47b5-9b13-0410-9fdd-eb0c1a62fdaf

lib/OpenLayers/Protocol.js

@@ -29,6 +29,12 @@ OpenLayers.Protocol = OpenLayers.Class({
      */
     autoDestroy: true,
    
+    /**
+     * Property: defaultFilter
+     * {OpenLayers.Filter} Optional default filter to read requests
+     */
+    defaultFilter: null,
+    
     /**
      * Constructor: OpenLayers.Protocol
      * Abstract class for vector protocols.  Create instances of a subclass.
@@ -43,6 +49,28 @@ OpenLayers.Protocol = OpenLayers.Class({
         this.options = options;
     },
 
+    /**
+     * Method: mergeWithDefaultFilter
+     * Merge filter passed to the read method with the default one
+     *
+     * Parameters:
+     * filter - {OpenLayers.Filter}
+     */
+    mergeWithDefaultFilter: function(filter) {
+        if(filter) {
+            if(this.defaultFilter) {
+                filter = new OpenLayers.Filter.Logical({
+                    type: OpenLayers.Filter.Logical.AND,
+                    filters: [this.defaultFilter, filter]
+                });
+            }
+        } else {
+            filter = this.defaultFilter;
+        }
+        return filter;
+    },
+
+
     /**
      * APIMethod: destroy
      * Clean up the protocol.
@@ -64,7 +92,9 @@ OpenLayers.Protocol = OpenLayers.Class({
      * object, the same object will be passed to the callback function passed
      * if one exists in the options object.
      */
-    read: function() {
+    read: function(options) {
+        options = options || {};
+        options.filter = this.mergeWithDefaultFilter(options.filter);
     },
     
     

lib/OpenLayers/Protocol/HTTP.js

@@ -136,6 +136,7 @@ OpenLayers.Protocol.HTTP = OpenLayers.Class(OpenLayers.Protocol, {
      *     is then populated with the the features received from the server.
      */
     read: function(options) {
+        OpenLayers.Protocol.prototype.read.apply(this, arguments);
         options = OpenLayers.Util.applyDefaults(options, this.options);
         var readWithPOST = (options.readWithPOST !== undefined) ?
                            options.readWithPOST : this.readWithPOST;

lib/OpenLayers/Protocol/SQL/Gears.js

@@ -154,6 +154,7 @@ OpenLayers.Protocol.SQL.Gears = OpenLayers.Class(OpenLayers.Protocol.SQL, {
      *      object.
      */
     read: function(options) {
+        OpenLayers.Protocol.prototype.read.apply(this, arguments);
         options = OpenLayers.Util.applyDefaults(options, this.options);
 
         var feature, features = [];

lib/OpenLayers/Protocol/WFS/v1.js

@@ -147,6 +147,7 @@ OpenLayers.Protocol.WFS.v1 = OpenLayers.Class(OpenLayers.Protocol, {
      *     responses).
      */
     read: function(options) {
+        OpenLayers.Protocol.prototype.read.apply(this, arguments);
         options = OpenLayers.Util.extend({}, options);
         OpenLayers.Util.applyDefaults(options, this.options || {});
         var response = new OpenLayers.Protocol.Response({requestType: "read"});

tests/Protocol.html

@@ -4,16 +4,36 @@
   <script type="text/javascript">
 
     function test_initialize(t) {
-        t.plan(3);
+        t.plan(4);
         var options = {};
         var protocol = new OpenLayers.Protocol(options);
 
         t.ok(protocol instanceof OpenLayers.Protocol,
              "new OpenLayers.Protocol returns object" );
         t.eq(protocol.options, options, "constructor sets this.options");
+        t.eq(protocol.options.filter, null, "constructor sets defaultFilter to null");
         t.eq(protocol.autoDestroy, true, "constructor does not modify this.autoDestroy");
     }
     
+    function test_read_defaultFilter(t) {
+        t.plan(3);
+        var defaultFilter = 'a';
+        var options = {
+            defaultFilter: defaultFilter
+        };
+
+        var protocol = new OpenLayers.Protocol(options);
+        var readFilter = 'b';
+        var options = { filter: readFilter };
+
+        protocol.read(options);
+
+        var filter = options.filter;
+        t.ok(filter instanceof OpenLayers.Filter.Logical, "read method merge default filter & options filter to a logical one");
+        t.eq(filter.type, OpenLayers.Filter.Logical.AND, "logical filter type is OpenLayers.Filter.Logical.AND");
+        t.eq(filter.filters, [defaultFilter, readFilter], "read method has merged filters");
+    }
+
     function test_destroy(t) {
         t.plan(2);
         var protocol = new OpenLayers.Protocol({