Make ng:repeat expose $position.

- $position is a textual representation of the position of
  repeated item ('first', 'middle', 'last')
- added specs for $index

Author: IgorMinar

src/directives.js

@@ -434,6 +434,10 @@ angularWidget("@ng:non-bindable", noop);
  *     scope expression giving the collection to enumerate. 
  *     For example: `(name, age) in {'adam':10, 'amalie':12}`.
  *
+ * Special properties set on the local scope:
+ *   * {number} $index - iterator offset of the repeated element (0..length-1)
+ *   * {string} $position - position of the repeated element in the iterator ('first', 'middle', 'last')
+ *
  * @exampleDescription
  * This example initializes the scope to a list of names and 
  * than uses `ng:repeat` to display every person.
@@ -477,9 +481,24 @@ angularWidget("@ng:repeat", function(expression, element){
 
     var children = [], currentScope = this;
     this.$onEval(function(){
-      var index = 0, childCount = children.length, childScope, lastElement = reference,
-          collection = this.$tryEval(rhs, reference), is_array = isArray(collection);
-      for ( var key in collection) {
+      var index = 0,
+          childCount = children.length,
+          lastElement = reference,
+          collection = this.$tryEval(rhs, reference), 
+          is_array = isArray(collection),
+          collectionLength = 0,
+          childScope,
+          key;
+
+      if (is_array) {
+        collectionLength = collection.length;
+      } else {
+        for (key in collection)
+          if (collection.hasOwnProperty(key))
+            collectionLength++;
+      }
+
+      for (key in collection) {
         if (!is_array || collection.hasOwnProperty(key)) {
           if (index < childCount) {
             // reuse existing child
@@ -493,6 +512,9 @@ angularWidget("@ng:repeat", function(expression, element){
             if (keyIdent) childScope[keyIdent] = key;
             lastElement.after(childScope.$element);
             childScope.$index = index;
+            childScope.$position = index == 0 ?
+                                      'first' :
+                                      (index == collectionLength - 1 ? 'last' : 'middle');
             childScope.$element.attr('ng:repeat-index', index);
             childScope.$init();
             children.push(childScope);

test/directivesSpec.js

@@ -135,39 +135,76 @@ describe("directives", function(){
     expect(element.text()).toEqual('');
   });
 
-  it('should ng:repeat over array', function(){
-    var scope = compile('<ul><li ng:repeat="item in items" ng:init="suffix = \';\'" ng:bind="item + suffix"></li></ul>');
 
-    Array.prototype.extraProperty = "should be ignored";
-    scope.items = ['misko', 'shyam'];
-    scope.$eval();
-    expect(element.text()).toEqual('misko;shyam;');
-    delete Array.prototype.extraProperty;
+  describe('ng:repeat', function() {
 
-    scope.items = ['adam', 'kai', 'brad'];
-    scope.$eval();
-    expect(element.text()).toEqual('adam;kai;brad;');
+    it('should ng:repeat over array', function(){
+      var scope = compile('<ul><li ng:repeat="item in items" ng:init="suffix = \';\'" ng:bind="item + suffix"></li></ul>');
 
-    scope.items = ['brad'];
-    scope.$eval();
-    expect(element.text()).toEqual('brad;');
-  });
+      Array.prototype.extraProperty = "should be ignored";
+      scope.items = ['misko', 'shyam'];
+      scope.$eval();
+      expect(element.text()).toEqual('misko;shyam;');
+      delete Array.prototype.extraProperty;
 
-  it('should ng:repeat over object', function(){
-    var scope = compile('<ul><li ng:repeat="(key, value) in items" ng:bind="key + \':\' + value + \';\' "></li></ul>');
-    scope.$set('items', {misko:'swe', shyam:'set'});
-    scope.$eval();
-    expect(element.text()).toEqual('misko:swe;shyam:set;');
-  });
+      scope.items = ['adam', 'kai', 'brad'];
+      scope.$eval();
+      expect(element.text()).toEqual('adam;kai;brad;');
+
+      scope.items = ['brad'];
+      scope.$eval();
+      expect(element.text()).toEqual('brad;');
+    });
+
+    it('should ng:repeat over object', function(){
+      var scope = compile('<ul><li ng:repeat="(key, value) in items" ng:bind="key + \':\' + value + \';\' "></li></ul>');
+      scope.$set('items', {misko:'swe', shyam:'set'});
+      scope.$eval();
+      expect(element.text()).toEqual('misko:swe;shyam:set;');
+    });
 
-  it('should error on wrong parsing of ng:repeat', function(){
-    var scope = compile('<ul><li ng:repeat="i dont parse"></li></ul>');
-    var log = "";
-    log += element.attr('ng-exception') + ';';
-    log += element.hasClass('ng-exception') + ';';
-    expect(log).toEqual("\"Expected ng:repeat in form of 'item in collection' but got 'i dont parse'.\";true;");
+    it('should error on wrong parsing of ng:repeat', function(){
+      var scope = compile('<ul><li ng:repeat="i dont parse"></li></ul>');
+      var log = "";
+      log += element.attr('ng-exception') + ';';
+      log += element.hasClass('ng-exception') + ';';
+      expect(log).toEqual("\"Expected ng:repeat in form of 'item in collection' but got 'i dont parse'.\";true;");
+    });
+
+    it('should expose iterator offset as $index when iterating over arrays', function() {
+      var scope = compile('<ul><li ng:repeat="item in items" ' +
+                                  'ng:bind="item + $index + \'|\'"></li></ul>');
+      scope.items = ['misko', 'shyam', 'frodo'];
+      scope.$eval();
+      expect(element.text()).toEqual('misko0|shyam1|frodo2|');
+    });
+
+    it('should expose iterator offset as $index when iterating over objects', function() {
+      var scope = compile('<ul><li ng:repeat="(key, val) in items" ' +
+                                  'ng:bind="key + \':\' + val + $index + \'|\'"></li></ul>');
+      scope.items = {'misko':'m', 'shyam':'s', 'frodo':'f'};
+      scope.$eval();
+      expect(element.text()).toEqual('misko:m0|shyam:s1|frodo:f2|');
+    });
+
+    it('should expose iterator position as $position when iterating over arrays', function() {
+      var scope = compile('<ul><li ng:repeat="item in items" ' +
+                                  'ng:bind="item + \':\' + $position + \'|\'"></li></ul>');
+      scope.items = ['misko', 'shyam', 'doug', 'frodo'];
+      scope.$eval();
+      expect(element.text()).toEqual('misko:first|shyam:middle|doug:middle|frodo:last|');
+    });
+
+    it('should expose iterator position as $position when iterating over objects', function() {
+      var scope = compile('<ul><li ng:repeat="(key, val) in items" ' +
+                                  'ng:bind="key + \':\' + val + \':\' + $position + \'|\'"></li></ul>');
+      scope.items = {'misko':'m', 'shyam':'s', 'doug':'d', 'frodo':'f'};
+      scope.$eval();
+      expect(element.text()).toEqual('misko:m:first|shyam:s:middle|doug:d:middle|frodo:f:last|');
+    });
   });
 
+
   it('should ng:watch', function(){
     var scope = compile('<div ng:watch="i: count = count + 1" ng:init="count = 0">');
     scope.$eval();