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

Fixes angular#562

Author: TEHEK

src/Compiler.js

@@ -33,7 +33,15 @@ 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 
+        // if child no longer available, delete path
+        delete paths[i];
     }
   },
 

src/widget/select.js

@@ -243,9 +243,12 @@ angularWidget('select', function(element){
 
       // find existing special options
       forEach(selectElement.children(), function(option){
-        if (option.value == '')
+        var opt;
+        if (option.value == '') {
+          opt = jqLite(option);
           // User is allowed to select the null.
-          nullOption = {label:jqLite(option).text(), id:''};
+          nullOption = {label:opt.text(), id:'', bindTemplate: opt.attr('ng:bind-template')};
+        }
       });
       selectElement.html(''); // clear contents
 
@@ -397,6 +400,14 @@ angularWidget('select', function(element){
                   .val(option.id)
                   .attr('selected', option.selected)
                   .text(option.label);
+
+              // if it's a nullOption, compile it
+              if (option.id === '') {
+                if (option.bindTemplate)
+                  element.attr('ng:bind-template', option.bindTemplate);
+                compile(element)(modelScope);
+              }
+
               existingOptions.push(existingOption = {
                   element: element,
                   label: option.label,

test/widget/selectSpec.js

@@ -429,6 +429,73 @@ describe('select', function() {
         expect(select.find('option').length).toEqual(1);
       });
     });
+    
+    describe('blank option', function () {
+
+      function createSelect(attrs, blank, unknown){
+        var html = '<select';
+        forEach(attrs, function(value, key){
+          if (isBoolean(value)) {
+            if (value) html += ' ' + key;
+          } else {
+            html += ' ' + key + '="' + value + '"';
+          }
+        });
+        html += '>' +
+          (blank ? blank : '') +
+          (unknown ? unknown : '') +
+        '</select>';
+        select = jqLite(html);
+        scope = compile(select);
+      }
+
+      function createSingleSelect(blank, unknown){
+        createSelect({
+          'ng:model':'selected',
+          'ng:options':'value.name for value in values'
+        }, blank, unknown);
+      }
+
+      it('should be compiled as template, be watched and updated', function () {
+        var option;
+
+        createSingleSelect('<option value="">blank is {{blankTemplate}}</option>');
+        scope.blankTemplate = '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 blankTemplate and $digest
+        scope.blankTemplate = 'not so blank';
+        scope.$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 be compiled from ng:bind-template attribute if given instead of text', function () {
+        var option;
+        
+        createSingleSelect('<option value="" ng:bind-template="blank is {{blankTemplate}}"></option>');
+        scope.blankTemplate = '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');
+      });
+    });
 
     describe('on change', function() {
       it('should update model on change', function() {