feat($resource): pass the resource to a dynamic param functions

Closes #4899

src/ngResource/resource.js

@@ -114,8 +114,9 @@ function shallowClearAndCopy(src, dst) {
  *   can escape it with `/\.`.
  *
  * @param {Object=} paramDefaults Default values for `url` parameters. These can be overridden in
- *   `actions` methods. If a parameter value is a function, it will be executed every time
- *   when a param value needs to be obtained for a request (unless the param was overridden).
+ *   `actions` methods. If a parameter value is a function, it will be called every time
+ *   a param value needs to be obtained for a request (unless the param was overridden). The function
+ *   will be passed the current data value as a argument.
  *
  *   Each key value in the parameter object is first bound to url template if present and then any
  *   excess keys are appended to the url search query after the `?`.
@@ -146,8 +147,9 @@ function shallowClearAndCopy(src, dst) {
  *   - **`method`** – {string} – Case insensitive HTTP method (e.g. `GET`, `POST`, `PUT`,
  *     `DELETE`, `JSONP`, etc).
  *   - **`params`** – {Object=} – Optional set of pre-bound parameters for this action. If any of
- *     the parameter value is a function, it will be executed every time when a param value needs to
- *     be obtained for a request (unless the param was overridden).
+ *     the parameter value is a function, it will be called every time when a param value needs to
+ *     be obtained for a request (unless the param was overridden). The function will be passed the
+ *     current data value as a argument.
  *   - **`url`** – {string} – action specific `url` override. The url templating is supported just
  *     like for the resource-level urls.
  *   - **`isArray`** – {boolean=} – If true then the returned object for this action is an array,
@@ -644,7 +646,7 @@ angular.module('ngResource', ['ng']).
           var ids = {};
           actionParams = extend({}, paramDefaults, actionParams);
           forEach(actionParams, function(value, key) {
-            if (isFunction(value)) { value = value(); }
+            if (isFunction(value)) { value = value(data); }
             ids[key] = value && value.charAt && value.charAt(0) === '@' ?
               lookupDottedPath(data, value.substr(1)) : value;
           });

test/ngResource/resourceSpec.js

@@ -643,7 +643,6 @@ describe("basic usage", function() {
     var currentGroup = 'students',
         Person = $resource('/Person/:group/:id', { group: function() { return currentGroup; }});
 
-
     $httpBackend.expect('GET', '/Person/students/fedor').respond({id: 'fedor', email: 'f@f.com'});
 
     var fedor = Person.get({id: 'fedor'});
@@ -653,6 +652,29 @@ describe("basic usage", function() {
   });
 
 
+  it('should pass resource object to dynamic default parameters', function() {
+    var Person = $resource('/Person/:id', {
+      id: function(data) {
+        return data ? data.id : 'fedor';
+      }
+    });
+
+    $httpBackend.expect('GET', '/Person/fedor').respond(
+        {id: 'fedor', email: 'f@f.com', count: 1});
+
+    var fedor = Person.get();
+    $httpBackend.flush();
+
+    expect(fedor).toEqualData({id: 'fedor', email: 'f@f.com', count: 1});
+
+    $httpBackend.expect('POST', '/Person/fedor').respond(
+        {id: 'fedor', email: 'f@f.com', count: 2});
+    fedor.$save();
+    $httpBackend.flush();
+    expect(fedor).toEqualData({id: 'fedor', email: 'f@f.com', count: 2});
+  });
+
+
   it('should support dynamic default parameters (action specific)', function() {
     var currentGroup = 'students',
       Person = $resource('/Person/:group/:id', {}, {