fix(ng:options): compile null/blank option tag

Fixes #562

src/Compiler.js

@@ -33,7 +33,14 @@ Template.prototype = {
         paths = this.paths,
         length = paths.length;
     for (i = 0; i < length; i++) {
-      children[i].link(jqLite(childNodes[paths[i]]), childScope);
+      // sometimes `element` can be modified by one of the linker functions in `this.linkFns`
+      // and childNodes may be added or removed
+      // TODO: element structure needs to be re-evaluated if new children added
+      // if the childNode still exists
+      if (childNodes[paths[i]])
+        children[i].link(jqLite(childNodes[paths[i]]), childScope);
+      else
+        delete paths[i]; // if child no longer available, delete path
     }
   },
 

src/widget/select.js

@@ -241,10 +241,13 @@ angularWidget('select', function(element){
           inChangeEvent;
 
       // find existing special options
-      forEach(selectElement.children(), function(option){
-        if (option.value == '')
-          // User is allowed to select the null.
-          nullOption = {label:jqLite(option).text(), id:''};
+      forEach(selectElement.children(), function(option) {
+        if (option.value == '') {
+          // developer declared null option, so user should be able to select it
+          nullOption = jqLite(option).remove();
+          // compile the element since there might be bindings in it
+          compile(nullOption)(modelScope);
+        }
       });
       selectElement.html(''); // clear contents
 
@@ -314,7 +317,7 @@ angularWidget('select', function(element){
           selectedSet = new HashMap(modelValue);
         } else if (modelValue === null || nullOption) {
           // if we are not multiselect, and we are null then we have to add the nullOption
-          optionGroups[''].push(extend({selected:modelValue === null, id:'', label:''}, nullOption));
+          optionGroups[''].push({selected:modelValue === null, id:'', label:''});
           selectedSet = true;
         }
 
@@ -389,13 +392,21 @@ angularWidget('select', function(element){
               }
             } else {
               // grow elements
-              // jQuery(v1.4.2) Bug: We should be able to chain the method calls, but
-              // in this version of jQuery on some browser the .text() returns a string
-              // rather then the element.
-              (element = optionTemplate.clone())
-                  .val(option.id)
-                  .attr('selected', option.selected)
-                  .text(option.label);
+
+              // if it's a null option
+              if (option.id === '' && nullOption) {
+                // put back the pre-compiled element
+                element = nullOption;
+              } else {
+                // jQuery(v1.4.2) Bug: We should be able to chain the method calls, but
+                // in this version of jQuery on some browser the .text() returns a string
+                // rather then the element.
+                (element = optionTemplate.clone())
+                    .val(option.id)
+                    .attr('selected', option.selected)
+                    .text(option.label);
+              }
+
               existingOptions.push(existingOption = {
                   element: element,
                   label: option.label,

test/widget/selectSpec.js

@@ -130,8 +130,8 @@ describe('select', function() {
         }
       });
       html += '>' +
-        (blank ? '<option value="">blank</option>' : '') +
-        (unknown ? '<option value="?">unknown</option>' : '') +
+        (blank ? (isString(blank) ? blank : '<option value="">blank</option>') : '') +
+        (unknown ? (isString(unknown) ? unknown : '<option value="?">unknown</option>') : '') +
       '</select>';
       select = jqLite(html);
       scope = compile(select);
@@ -445,6 +445,80 @@ describe('select', function() {
       });
     });
 
+
+    describe('blank option', function () {
+      it('should be compiled as template, be watched and updated', function () {
+        var option;
+
+        createSingleSelect('<option value="">blank is {{blankVal}}</option>');
+        scope.blankVal = 'so blank';
+        scope.values = [{name:'A'}];
+        scope.$digest();
+
+        // check blank option is first and is compiled
+        expect(select.find('option').length == 2);
+        option = jqLite(select.find('option')[0]);
+        expect(option.val()).toBe('');
+        expect(option.text()).toBe('blank is so blank');
+
+        // change blankVal and $digest
+        scope.blankVal = 'not so blank';
+        scope.$digest();
+
+        // check blank option is first and is compiled
+        expect(select.find('option').length == 2);
+        option = jqLite(select.find('option')[0]);
+        expect(option.val()).toBe('');
+        expect(option.text()).toBe('blank is not so blank');
+      });
+
+      it('should support binding via ng:bind-template attribute', function () {
+        var option;
+
+        createSingleSelect('<option value="" ng:bind-template="blank is {{blankVal}}"></option>');
+        scope.blankVal = 'so blank';
+        scope.values = [{name:'A'}];
+        scope.$digest();
+
+        // check blank option is first and is compiled
+        expect(select.find('option').length == 2);
+        option = jqLite(select.find('option')[0]);
+        expect(option.val()).toBe('');
+        expect(option.text()).toBe('blank is so blank');
+      });
+
+      it('should support biding via ng:bind attribute', function () {
+        var option;
+
+        createSingleSelect('<option value="" ng:bind="blankVal"></option>');
+        scope.blankVal = 'is blank';
+        scope.values = [{name:'A'}];
+        scope.$digest();
+
+        // check blank option is first and is compiled
+        expect(select.find('option').length == 2);
+        option = jqLite(select.find('option')[0]);
+        expect(option.val()).toBe('');
+        expect(option.text()).toBe('is blank');
+      });
+
+      it('should be rendered with the attributes preserved', function () {
+        var option;
+
+        createSingleSelect('<option value="" class="coyote" id="road-runner" ' +
+          'custom-attr="custom-attr">{{blankVal}}</option>');
+        scope.blankVal = 'is blank';
+        scope.$digest();
+
+        // check blank option is first and is compiled
+        option = jqLite(select.find('option')[0]);
+        expect(option.hasClass('coyote')).toBeTruthy();
+        expect(option.attr('id')).toBe('road-runner');
+        expect(option.attr('custom-attr')).toBe('custom-attr');
+      });
+    });
+
+
     describe('on change', function() {
       it('should update model on change', function() {
         createSingleSelect();