feat($compile): support expansion of special ngAutobind attributes

In order to reduce some of the verbosity associated with conforming to the
ideas behind unidirectional data-flow, we can introduce a special
attribute syntax that will be automatically expanded in order to simulate
two-way data binding.

For example,

`<my-component ng-autobind-foo="bar">` will be expanded into
`<my-component foo="bar" foo-changed="bar = $event">`

Fixes #15455

Author: dcherman

src/ng/compile.js

@@ -1803,7 +1803,7 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
             : function denormalizeTemplate(template) {
               return template.replace(/\{\{/g, startSymbol).replace(/}}/g, endSymbol);
         },
-        NG_ATTR_BINDING = /^ngAttr[A-Z]/;
+        NG_ATTR_BINDING = /^ng(Attr|Autobind)[A-Z]/;
     var MULTI_ELEMENT_DIR_RE = /^(.+)Start$/;
 
     compile.$$addBindingInfo = debugInfoEnabled ? function $$addBindingInfo($element, binding) {
@@ -2150,10 +2150,14 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
 
             // support ngAttr attribute binding
             ngAttrName = directiveNormalize(name);
-            isNgAttr = NG_ATTR_BINDING.test(ngAttrName);
-            if (isNgAttr) {
+
+            var isSpecialAttr = NG_ATTR_BINDING.exec(ngAttrName);
+            var isNgAttr = isSpecialAttr && isSpecialAttr[1] === 'Attr';
+            var isNgAutobind = isSpecialAttr && isSpecialAttr[1] === 'Autobind';
+
+            if (isSpecialAttr) {
               name = name.replace(PREFIX_REGEXP, '')
-                .substr(8).replace(/_(.)/g, function(match, letter) {
+                .substr(isNgAttr ? 8 : 12).replace(/_(.)/g, function(match, letter) {
                   return letter.toUpperCase();
                 });
             }
@@ -2173,6 +2177,12 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
                   attrs[nName] = true; // presence means true
                 }
             }
+
+            if (isNgAutobind) {
+              attrs[name] = value;
+              attrs[name + 'Change'] = value + '= $event';
+            }
+
             addAttrInterpolateDirective(node, directives, value, nName, isNgAttr);
             addDirective(directives, nName, 'A', maxPriority, ignoreDirective, attrStartName,
                           attrEndName);