Exposed current Context to lambdas via Mustache.currentContext

mustache.js

@@ -22,6 +22,7 @@ var Mustache;
   exports.name = "mustache.js";
   exports.version = "0.7.0";
   exports.tags = ["{{", "}}"];
+  exports.currentContext = null; // behavior is defined only when dereferenced from within a lambda call
 
   exports.Scanner = Scanner;
   exports.Context = Context;
@@ -125,9 +126,11 @@ var Mustache;
     return match;
   };
 
-  function Context(view, parent) {
+  function Context(view, parent, index, array) {
     this.view = view;
     this.parent = parent;
+    if (!!index) this.index = index;
+    this.array = array;
     this.clearCache();
   }
 
@@ -139,8 +142,8 @@ var Mustache;
     this._cache = {};
   };
 
-  Context.prototype.push = function (view) {
-    return new Context(view, this);
+  Context.prototype.push = function (view, index, array) {
+    return new Context(view, this, index, array);
   };
 
   Context.prototype.lookup = function (name) {
@@ -177,12 +180,15 @@ var Mustache;
     }
 
     if (typeof value === "function") {
+      exports.currentContext = this;
       value = value.call(this.view);
     }
 
     return value;
   };
 
+  Context.prototype.index = 0;
+
   function Writer() {
     this.clearCache();
   }
@@ -241,7 +247,7 @@ var Mustache;
         var buffer = "";
 
         for (var i = 0, len = value.length; i < len; ++i) {
-          buffer += callback(this, context.push(value[i]));
+          buffer += callback(this, context.push(value[i], i, value));
         }
 
         return buffer;
@@ -254,6 +260,7 @@ var Mustache;
         return self.render(template, context);
       };
 
+      exports.currentContext = context;
       return value.call(context.view, text, scopedRender) || "";
     default:
       if (value) {
@@ -290,6 +297,7 @@ var Mustache;
     var value = context.lookup(name);
 
     if (typeof value === "function") {
+      exports.currentContext = context;
       value = value.call(context.view);
     }
 

test/_files/current_context_last.js

@@ -0,0 +1,7 @@
+({
+    items:[1,2,3],
+    last: function() {
+        var ctx = Mustache.currentContext;
+        return (ctx.array.length === ctx.index+1);
+    }
+})

test/_files/current_context_last.mustache

@@ -0,0 +1,2 @@
+{{#items}}{{.}}{{^last}}, {{/last}}{{/items}}
+

test/_files/current_context_last.txt

@@ -0,0 +1,2 @@
+1, 2, 3
+

test/_files/current_context_oddeven.js

@@ -0,0 +1,7 @@
+({
+    rows: [1,2,3],
+    oddeven: function() {
+        var ctx = Mustache.currentContext;
+        return (ctx.index % 2) ? 'even' : 'odd';
+    }
+})

test/_files/current_context_oddeven.mustache

@@ -0,0 +1,5 @@
+<table>
+{{#rows}}
+<tr class="{{oddeven}}"><td>{{.}}</td></tr>
+{{/rows}}
+</table>

test/_files/current_context_oddeven.txt

@@ -0,0 +1,5 @@
+<table>
+<tr class="odd"><td>1</td></tr>
+<tr class="even"><td>2</td></tr>
+<tr class="odd"><td>3</td></tr>
+</table>