base: introduce recordExtensions API

veged · Sep 30, 2013 · 2060027 · 2060027
1 parent 05447c1
commit 2060027
Show file tree

Hide file tree

Showing 2 changed files with 62 additions and 3 deletions.
diff --git a/lib/xjst/compiler/base.js b/lib/xjst/compiler/base.js
@@ -34,6 +34,10 @@ function Compiler(options) {
   this.renderCacheMap = {};
   this.sharedBodies = {};
   this.maps = {};
+
+  // Context extensions from local({}) stmts
+  this.extensions = {};
+
   this.program = null;
   this.inputProgram = null;
 
@@ -66,7 +70,11 @@ Compiler.prototype.generate = function generate(code) {
            '  return run(templates, ctx);\n' +
            '};\n' +
            'try {\n' +
-           '  applyc({ $init:true, $exports: exports, $context: {} });\n' +
+           '  applyc({\n' +
+           '    $init:true,\n' +
+           '    $exports: exports,\n' +
+           '    $context: { recordExtensions: function() {} }\n' +
+           '  });\n' +
            '} catch (e) {\n' +
            '  // Just ignore any errors\n' +
            '}\n' +
@@ -640,6 +648,50 @@ Compiler.prototype.sortGroup = function sortGroup(templates) {
   return out;
 };
 
+Compiler.prototype.registerExtension = function registerExtension(name) {
+  if (name !== '__proto__')
+    this.extensions[name] = true;
+};
+
+Compiler.prototype.getRecordExtensions = function getRecordExtensions() {
+  var ctx = { type: 'Identifier', name: 'ctx' };
+  var body = [];
+
+  Object.keys(this.extensions).forEach(function(name) {
+    body.push({
+      type: 'ExpressionStatement',
+      expression: {
+        type: 'AssignmentExpression',
+        operator: '=',
+        left: {
+          type: 'MemberExpression',
+          computed: false,
+          object: ctx,
+          property: { type: 'Identifier', name: name }
+        },
+
+        // Apply flags should have boolean value
+        right: /^__\$a/.test(name) ? { type: 'Literal', value: false } :
+                                     { type: 'Identifier', name: 'undefined' }
+      }
+    });
+  });
+
+  return {
+    type: 'FunctionExpression',
+    id: null,
+    params: [ ctx ],
+    defaults: [],
+    rest: null,
+    generator: false,
+    expression: false,
+    body: {
+      type: 'BlockStatement',
+      body: body
+    }
+  };
+};
+
 Compiler.prototype.render = function render(program, bodyOnly) {
   var stmts = [],
       initializers = program.init.slice(),
@@ -750,7 +802,7 @@ Compiler.prototype.render = function render(program, bodyOnly) {
   stmts.push(applyc);
 
   // Call applyc once to allow users override exports
-  // [init functions].forEach(function(fn) { fn(exports) });
+  // [init functions].forEach(function(fn) { fn(exports, this) }, ctx);
   stmts.push({
     type: 'ExpressionStatement',
     expression: {
@@ -788,7 +840,12 @@ Compiler.prototype.render = function render(program, bodyOnly) {
         }
       }, {
         type: 'ObjectExpression',
-        properties: []
+        properties: [{
+          type: 'Property',
+          key: { type: 'Literal', value: 'recordExtensions' },
+          value: this.getRecordExtensions(),
+          kind: 'init'
+        }]
       }]
     }
   });

diff --git a/lib/xjst/compiler/entities/body.js b/lib/xjst/compiler/entities/body.js
@@ -240,6 +240,8 @@ Body.prototype.rollOutLocal = function rollOutLocal(ast, changes, body) {
               property: { type: 'Identifier', name: right }
             };
 
+            self.compiler.registerExtension(right);
+
             return sub;
           }, ctx);