feat($parse): enable optional access to the underlying AST

src/ng/parse.js

@@ -1644,11 +1644,26 @@ Parser.prototype = {
   constructor: Parser,
 
   parse: function(text) {
-    var ast = this.ast.ast(text);
-    var fn = this.astCompiler.compile(ast);
-    fn.literal = isLiteral(ast);
-    fn.constant = isConstant(ast);
+    var ast = this.getAst(text);
+    var fn = this.astCompiler.compile(ast.ast);
+    fn.literal = isLiteral(ast.ast);
+    fn.constant = isConstant(ast.ast);
+    fn.oneTime = ast.oneTime;
     return fn;
+  },
+
+  getAst: function(exp) {
+    var oneTime = false;
+    exp = exp.trim();
+
+    if (exp.charAt(0) === ':' && exp.charAt(1) === ':') {
+      oneTime = true;
+      exp = exp.substring(2);
+    }
+    return {
+      ast: this.ast.ast(exp),
+      oneTime: oneTime
+    };
   }
 };
 
@@ -1771,10 +1786,11 @@ function $ParseProvider() {
           isIdentifierStart: isFunction(identStart) && identStart,
           isIdentifierContinue: isFunction(identContinue) && identContinue
         };
+    $parse.$$getAst = $$getAst;
     return $parse;
 
     function $parse(exp, interceptorFn) {
-      var parsedExpression, oneTime, cacheKey;
+      var parsedExpression, cacheKey;
 
       switch (typeof exp) {
         case 'string':
@@ -1784,14 +1800,9 @@ function $ParseProvider() {
           parsedExpression = cache[cacheKey];
 
           if (!parsedExpression) {
-            if (exp.charAt(0) === ':' && exp.charAt(1) === ':') {
-              oneTime = true;
-              exp = exp.substring(2);
-            }
             var lexer = new Lexer($parseOptions);
             var parser = new Parser(lexer, $filter, $parseOptions);
             parsedExpression = parser.parse(exp);
-            parsedExpression.oneTime = !!oneTime;
 
             cache[cacheKey] = addWatchDelegate(parsedExpression);
           }
@@ -1805,6 +1816,12 @@ function $ParseProvider() {
       }
     }
 
+    function $$getAst(exp) {
+      var lexer = new Lexer($parseOptions);
+      var parser = new Parser(lexer, $filter, $parseOptions);
+      return parser.getAst(exp).ast;
+    }
+
     function expressionInputDirtyCheck(newValue, oldValueOfValue, compareObjectIdentity) {
 
       if (newValue == null || oldValueOfValue == null) { // null/undefined

test/ng/parseSpec.js

@@ -4245,4 +4245,48 @@ describe('parser', function() {
       });
     });
   });
+
+  describe('hidden/unsupported features', function() {
+    describe('$$getAst()', function() {
+      it('should be a method exposed on the `$parse` service', inject(function($parse) {
+        expect(isFunction($parse.$$getAst)).toBeTruthy();
+      }));
+
+      it('should accept a string expression argument and return the corresponding AST', inject(function($parse) {
+        var ast = $parse.$$getAst('foo.bar');
+        expect(ast).toEqual({
+          type: 'Program',
+          body: [
+            {
+              type: 'ExpressionStatement',
+              expression: {
+                type: 'MemberExpression',
+                object: { type: 'Identifier', name: 'foo' },
+                property: { type: 'Identifier', name: 'bar' },
+                computed: false
+              }
+            }
+          ]
+        });
+      }));
+
+      it('should parse one time binding expressions', inject(function($parse) {
+        var ast = $parse.$$getAst('::foo.bar');
+        expect(ast).toEqual({
+          type: 'Program',
+          body: [
+            {
+              type: 'ExpressionStatement',
+              expression: {
+                type: 'MemberExpression',
+                object: { type: 'Identifier', name: 'foo' },
+                property: { type: 'Identifier', name: 'bar' },
+                computed: false
+              }
+            }
+          ]
+        });
+      }));
+    });
+  });
 });