From 4b79321fbd59b4fd7e97ff82257958993185ab01 Mon Sep 17 00:00:00 2001
From: Caitlin Potter <snowball@defpixel.com>
Date: Thu, 3 Oct 2013 18:11:29 -0400
Subject: [PATCH] feat(ngAttr): implement conditional/interpolated attributes
 directive

The ngAttr directive allows for attributes to be conditionally applied to an
element. It also supports attributes with interpolated values.

1. Simple case: `ng-attr="{checked: isChecked}"`

2. With values: `ng-attr="'data-whatever={{value}}'"`

3. Set of attributes with interpolated values:
   `ng-attr="['attr1={{a}}', 'attr2={{b()}}']"`

4. Conditional attributes with values:
   `ng-attr="{'data-whatever=shmee': showWhatever&&!flurp()}"`
---
 angularFiles.js                 |   1 +
 src/AngularPublic.js            |   2 +
 src/ng/directive/ngAttr.js      |  76 +++++++++++
 test/ng/directive/ngAttrSpec.js | 231 ++++++++++++++++++++++++++++++++
 4 files changed, 310 insertions(+)
 create mode 100644 src/ng/directive/ngAttr.js
 create mode 100644 test/ng/directive/ngAttrSpec.js

diff --git a/angularFiles.js b/angularFiles.js
index ad968341abf9..302b47cfc763 100755
--- a/angularFiles.js
+++ b/angularFiles.js
@@ -45,6 +45,7 @@ angularFiles = {
     'src/ng/directive/booleanAttrs.js',
     'src/ng/directive/form.js',
     'src/ng/directive/input.js',
+    'src/ng/directive/ngAttr.js',
     'src/ng/directive/ngBind.js',
     'src/ng/directive/ngClass.js',
     'src/ng/directive/ngCloak.js',
diff --git a/src/AngularPublic.js b/src/AngularPublic.js
index 14fe25aec20a..7ab83d0c179a 100644
--- a/src/AngularPublic.js
+++ b/src/AngularPublic.js
@@ -15,6 +15,7 @@
     selectDirective,
     styleDirective,
     optionDirective,
+    ngAttrDirective,
     ngBindDirective,
     ngBindHtmlDirective,
     ngBindTemplateDirective,
@@ -152,6 +153,7 @@ function publishExternalAPI(angular){
             select: selectDirective,
             style: styleDirective,
             option: optionDirective,
+            ngAttr: ngAttrDirective,
             ngBind: ngBindDirective,
             ngBindHtml: ngBindHtmlDirective,
             ngBindTemplate: ngBindTemplateDirective,
diff --git a/src/ng/directive/ngAttr.js b/src/ng/directive/ngAttr.js
new file mode 100644
index 000000000000..e7f08a95cc4e
--- /dev/null
+++ b/src/ng/directive/ngAttr.js
@@ -0,0 +1,76 @@
+'use strict';
+
+function attrDirective(name, selector) {
+  name = 'ngAttr' + name;
+  return function() {
+    var ATTR_MATCH = /\s*([^=]+)(=\s*(\S+))?/;
+    return {
+      restrict: 'A',
+      link: function(scope, element, attr) {
+        var oldVal;
+
+        scope.$watch(attr[name], function(value) {
+          ngAttrWatchAction(scope.$eval(attr[name]));
+        }, true);
+
+        attr.$observe(name, function() {
+          ngAttrWatchAction(scope.$eval(attr[name]));
+        });
+
+        function ngAttrWatchAction(newVal) {
+          if (selector === true || scope.$index % 2 === selector) {
+            if (oldVal && !equals(newVal,oldVal)) {
+              attrWorker(oldVal, removeAttr);
+            }
+            attrWorker(newVal, setAttr);
+          }
+          oldVal = copy(newVal);
+        }
+
+
+        function splitAttr(value) {
+          var m = ATTR_MATCH.exec(value);
+          return m && [m[1].replace(/\s+$/, ''), m[3]];
+        }
+
+
+        function setAttr(value) {
+          if (value) {
+            if (value[0] === 'undefined' || value[0] === 'null') {
+              return;
+            }
+            element.attr(value[0], isDefined(value[1]) ? value[1] : '');
+          }
+        }
+
+        function removeAttr(value) {
+          if (value) {
+            element.removeAttr(value[0]);
+          }
+        }
+
+        function attrWorker(attrVal, action, compare) {
+          if(isString(attrVal)) {
+            attrVal = attrVal.split(/\s+/);
+          }
+          if(isArray(attrVal)) {
+            forEach(attrVal, function(v) {
+              v = splitAttr(v);
+              action(v);
+            });
+          } else if (isObject(attrVal)) {
+            var attrs = [];
+            forEach(attrVal, function(v, k) {
+              k = splitAttr(k);
+              if (v) {
+                action(k);
+              }
+            });
+          }
+        }
+      }
+    };
+  };
+}
+
+var ngAttrDirective = attrDirective('', true);
\ No newline at end of file
diff --git a/test/ng/directive/ngAttrSpec.js b/test/ng/directive/ngAttrSpec.js
new file mode 100644
index 000000000000..755799029f69
--- /dev/null
+++ b/test/ng/directive/ngAttrSpec.js
@@ -0,0 +1,231 @@
+'use strict';
+
+describe('ngAttr', function() {
+  var element;
+
+
+  afterEach(function() {
+    dealoc(element);
+  });
+
+
+  it('should add new and remove old attributes dynamically', inject(function($rootScope, $compile) {
+    element = $compile('<div existing ng-attr="dynAttr"></div>')($rootScope);
+    $rootScope.dynAttr = 'A';
+    $rootScope.$digest();
+    expect(element.attr('A')).toBe('');
+    expect(element.attr('B')).toBeUndefined();
+
+    $rootScope.dynAttr = 'B';
+    $rootScope.$digest();
+    expect(element.attr('existing')).toBe('');
+    expect(element.attr('A')).toBeUndefined();
+    expect(element.attr('B')).toBe('');
+
+    delete $rootScope.dynAttr;
+    $rootScope.$digest();
+    expect(element.attr('existing')).toBe('');
+    expect(element.attr('A')).toBeUndefined();
+    expect(element.attr('B')).toBeUndefined();
+  }));
+
+
+  it('should support adding multiple attributes via an array',
+  inject(function($rootScope, $compile) {
+    element = $compile('<div existing ng-attr="[\'A\', \'B\']"></div>')($rootScope);
+    $rootScope.$digest();
+    expect(element.attr('existing')).toBe('');
+    expect(element.attr('A')).toBe('');
+    expect(element.attr('B')).toBe('');
+  }));
+
+
+  it('should support adding multiple attributes conditionally via a map of attribute names to' +
+     ' boolean expressions', inject(function($rootScope, $compile) {
+    var element = $compile(
+        '<div existing ' +
+            'ng-attr="{A: conditionA, B: conditionB(), AnotB: conditionA&&!conditionB()}">' +
+        '</div>')($rootScope);
+    $rootScope.conditionA = true;
+    $rootScope.$digest();
+    expect(element.attr('existing')).toBe('');
+    expect(element.attr('A')).toBe('');
+    expect(element.attr('B')).toBeUndefined();
+    expect(element.attr('AnotB')).toBe('');
+
+    $rootScope.conditionB = function() { return true; };
+    $rootScope.$digest();
+    expect(element.attr('existing')).toBe('');
+    expect(element.attr('A')).toBe('');
+    expect(element.attr('B')).toBe('');
+    expect (element.attr('AnotB')).toBeUndefined();
+  }));
+
+
+  it('should support adding multiple attributes with values conditionally via a map of attribute ' +
+     'names to boolean expressions',
+  inject(function($rootScope, $compile) {
+    var element = $compile(
+        '<div existing ' +
+            'ng-attr="{\'A={{a()}}\': conditionA, \'B={{b}}\': conditionB()}">' +
+        '</div>')($rootScope);
+
+    $rootScope.conditionA = true;
+    $rootScope.$digest();
+
+    $rootScope.a = function() { return "forty-two"; };
+    $rootScope.b = "snow-crash";
+    
+    $rootScope.$digest();
+
+    expect(element.attr('a')).toBe('forty-two');
+    expect(element.attr('b')).toBeUndefined();
+
+    $rootScope.conditionB = function() { return true; };
+    $rootScope.$digest();
+    expect(element.attr('a')).toBe('forty-two');
+    expect(element.attr('b')).toBe('snow-crash');
+  }));
+
+
+  it('should remove attributes when the referenced object is the same but its property is changed',
+  inject(function($rootScope, $compile) {
+    var element = $compile('<div ng-attr="attributes"></div>')($rootScope);
+    $rootScope.attributes = { A: true, B: true };
+    $rootScope.$digest();
+    expect(element.attr('A')).toBe('');
+    expect(element.attr('B')).toBe('');
+    $rootScope.attributes.A = false;
+    $rootScope.$digest();
+    expect(element.attr('A')).toBeUndefined();
+    expect(element.attr('B')).toBe('');
+  }));
+
+
+  it('should support adding attributes with values', inject(function($rootScope, $compile) {
+    var element = $compile('<div ng-attr="\'value=seventy\'"></div>')($rootScope);
+    $rootScope.$digest();
+    expect(element.attr('value')).toBe('seventy');
+  }));
+
+
+  it('should support adding multiple attributes via a space delimited string',
+  inject(function($rootScope, $compile) {
+    element = $compile('<div existing ng-attr="\'A B\'"></div>')($rootScope);
+    $rootScope.$digest();
+    expect(element.attr('existing')).toBe('');
+    expect(element.attr('A')).toBe('');
+    expect(element.attr('B')).toBe('');
+  }));
+
+
+  it('should support adding multiple attributes with values via array notation',
+  inject(function($rootScope, $compile) {
+    var element = $compile('<div ng-attr="[\'value=seventy\', \'value2=spork\']"></div>')($rootScope);
+    $rootScope.$digest();
+    expect(element.attr('value')).toBe('seventy');
+    expect(element.attr('value2')).toBe('spork');
+  }));
+
+
+  it('should preserve attribute added post compilation with pre-existing attributes',
+  inject(function($rootScope, $compile) {
+    element = $compile('<div existing ng-attr="dynAttr"></div>')($rootScope);
+    $rootScope.dynAttr = 'A';
+    $rootScope.$digest();
+    expect(element.attr('existing')).toBe('');
+
+    // add extra attribute, change model and eval
+    element.attr('newAttr','');
+    $rootScope.dynAttr = 'B';
+    $rootScope.$digest();
+
+    expect(element.attr('existing')).toBe('');
+    expect(element.attr('B')).toBe('');
+    expect(element.attr('newAttr')).toBe('');
+  }));
+
+
+  it('should preserve attribute added post compilation without pre-existing attributes"',
+  inject(function($rootScope, $compile) {
+    element = $compile('<div ng-attr="dynAttr"></div>')($rootScope);
+    $rootScope.dynAttr = 'A';
+    $rootScope.$digest();
+    expect(element.attr('A')).toBe('');
+
+    // add extra attribute, change model and eval
+    element.attr('newAttr','');
+    $rootScope.dynAttr = 'B';
+    $rootScope.$digest();
+
+    expect(element.attr('B')).toBe('');
+    expect(element.attr('newAttr')).toBe('');
+  }));
+
+
+  it('should preserve other attributes with similar name"', inject(function($rootScope, $compile) {
+    element = $compile('<div ui-panel ui-selected ng-attr="dynAttr"></div>')($rootScope);
+    $rootScope.dynAttr = 'panel';
+    $rootScope.$digest();
+    $rootScope.dynAttr = 'foo';
+    $rootScope.$digest();
+    expect(element.attr('ui-panel')).toBe('');
+    expect(element.attr('ui-selected')).toBe('');
+    expect(element.attr('foo')).toBe('');
+  }));
+
+
+  it('should not add duplicate attributes', inject(function($rootScope, $compile) {
+    element = $compile('<div panel bar ng-attr="dynAttr"></div>')($rootScope);
+    $rootScope.dynAttr = 'panel';
+    $rootScope.$digest();
+    expect(element.attr('panel')).toBe('');
+    expect(element.attr('bar')).toBe('');
+  }));
+
+
+  it('should remove attributes even if it was specified outside ng-attr',
+  inject(function($rootScope, $compile) {
+    element = $compile('<div panel bar ng-attr="dynAttr"></div>')($rootScope);
+    $rootScope.dynAttr = 'panel';
+    $rootScope.$digest();
+    $rootScope.dynAttr = 'window';
+    $rootScope.$digest();
+    expect(element.attr('bar')).toBe('');
+    expect(element.attr('window')).toBe('');
+  }));
+
+
+  it('should remove attributes even if they were added by another code',
+  inject(function($rootScope, $compile) {
+    element = $compile('<div ng-attr="dynAttr"></div>')($rootScope);
+    $rootScope.dynAttr = 'foo';
+    $rootScope.$digest();
+    element.attr('foo', '');
+    $rootScope.dynAttr = '';
+    $rootScope.$digest();
+    expect(element.attr('foo')).toBeUndefined();
+  }));
+
+
+  it('should not add attributes with empty names',
+  inject(function($rootScope, $compile) {
+    element = $compile('<div ng-attr="dynAttr"></div>')($rootScope);
+    $rootScope.dynAttr = [undefined, null];
+    $rootScope.$digest();
+    expect(element.attr('undefined')).toBeUndefined();
+    expect(element.attr('null')).toBeUndefined();
+  }));
+
+
+  it('should not mess up attribute value due to observing an interpolated attribute',
+  inject(function($rootScope, $compile) {
+    $rootScope.foo = true;
+    $rootScope.$watch("anything", function() {
+      $rootScope.foo = false;
+    });
+    element = $compile('<div ng-attr="{foo:foo}"></div>')($rootScope);
+    $rootScope.$digest();
+    expect(element.attr('foo')).toBeUndefined();
+  }));
+});