Merge pull request #819 from wycats/compat-mode

Implement recursive field lookup

1 files changed, 45 insertions, 21 deletions

diff --git a/lib/handlebars/compiler/javascript-compiler.js b/lib/handlebars/compiler/javascript-compiler.js
index c92cf58..b9b858d 100644
--- a/lib/handlebars/compiler/javascript-compiler.js
+++ b/lib/handlebars/compiler/javascript-compiler.js
@@ -17,6 +17,11 @@ JavaScriptCompiler.prototype = {
       return parent + "['" + name + "']";
     }
   },
+  depthedLookup: function(name) {
+    this.aliases.lookup = 'this.lookup';
+
+    return 'lookup(depths, "' + name + '")';
+  },
 
   compilerInfo: function() {
     var revision = COMPILER_REVISION,
@@ -69,6 +74,8 @@ JavaScriptCompiler.prototype = {
 
     this.compileChildren(environment, options);
 
+    this.useDepths = this.useDepths || environment.depths.list.length || this.options.compat;
+
     var opcodes = environment.opcodes,
         opcode,
         i,
@@ -115,6 +122,9 @@ JavaScriptCompiler.prototype = {
       if (this.options.data) {
         ret.useData = true;
       }
+      if (this.useDepths) {
+        ret.depths = true;
+      }
 
       if (!asObject) {
         ret.compiler = JSON.stringify(ret.compiler);
@@ -151,8 +161,8 @@ JavaScriptCompiler.prototype = {
 
     var params = ["depth0", "helpers", "partials", "data"];
 
-    for(var i=0, l=this.environment.depths.list.length; i<l; i++) {
-      params.push("depth" + this.environment.depths.list[i]);
+    if (this.useDepths) {
+      params.push('depths');
     }
 
     // Perform a second pass over the output to merge content when possible
@@ -230,7 +240,7 @@ JavaScriptCompiler.prototype = {
   blockValue: function(name) {
     this.aliases.blockHelperMissing = 'helpers.blockHelperMissing';
 
-    var params = ["depth0"];
+    var params = [this.contextName(0)];
     this.setupParams(name, 0, params);
 
     this.replaceStack(function(current) {
@@ -249,7 +259,7 @@ JavaScriptCompiler.prototype = {
     this.aliases.blockHelperMissing = 'helpers.blockHelperMissing';
 
     // We're being a bit cheeky and reusing the options value from the prior exec
-    var params = ["depth0"];
+    var params = [this.contextName(0)];
     this.setupParams('', 0, params, true);
 
     this.flushInline();
@@ -341,7 +351,7 @@ JavaScriptCompiler.prototype = {
   //
   // Pushes the value of the current context onto the stack.
   pushContext: function() {
-    this.pushStackLiteral('depth' + this.lastContext);
+    this.pushStackLiteral(this.contextName(this.lastContext));
   },
 
   // [lookupOnContext]
@@ -351,15 +361,20 @@ JavaScriptCompiler.prototype = {
   //
   // Looks up the value of `name` on the current context and pushes
   // it onto the stack.
-  lookupOnContext: function(parts, falsy) {
+  lookupOnContext: function(parts, falsy, scoped) {
     /*jshint -W083 */
-    this.pushContext();
-    if (!parts) {
-      return;
+    var i = 0,
+        len = parts.length;
+
+    if (!scoped && this.isChild && this.options.compat && !this.lastContext) {
+      // The depthed query is expected to handle the undefined logic for the root level that
+      // is implemented below, so we evaluate that directly in compat mode
+      this.pushStackLiteral(this.depthedLookup(parts[i++]));
+    } else {
+      this.pushContext();
     }
 
-    var len = parts.length;
-    for (var i = 0; i < len; i++) {
+    for (; i < len; i++) {
       this.replaceStack(function(current) {
         var lookup = this.nameLookup(current, parts[i], 'context');
         // We want to ensure that zero and false are handled properly for the first element
@@ -410,7 +425,7 @@ JavaScriptCompiler.prototype = {
   resolvePossibleLambda: function() {
     this.aliases.lambda = 'this.lambda';
 
-    this.push('lambda(' + this.popStack() + ', depth0)');
+    this.push('lambda(' + this.popStack() + ', ' + this.contextName(0) + ')');
   },
 
   // [pushStringParam]
@@ -422,8 +437,7 @@ JavaScriptCompiler.prototype = {
   // provides the string value of a parameter along with its
   // depth rather than resolving it immediately.
   pushStringParam: function(string, type) {
-    this.pushStackLiteral('depth' + this.lastContext);
-
+    this.pushContext();
     this.pushString(type);
 
     // If it's a subexpression, the string result
@@ -669,6 +683,8 @@ JavaScriptCompiler.prototype = {
         child.name = 'program' + index;
         this.context.programs[index] = compiler.compile(child, options, this.context, !this.precompile);
         this.context.environments[index] = child;
+
+        this.useDepths = this.useDepths || compiler.useDepths;
       } else {
         child.index = index;
         child.name = 'program' + index;
@@ -690,17 +706,17 @@ JavaScriptCompiler.prototype = {
     }
 
     var child = this.environment.children[guid],
-        depths = child.depths.list, depth;
+        depths = child.depths.list,
+        useDepths = this.useDepths,
+        depth;
 
     var programParams = [child.index, 'data'];
 
-    for(var i=0, l = depths.length; i<l; i++) {
-      depth = depths[i];
-
-      programParams.push('depth' + (depth - 1));
+    if (useDepths) {
+      programParams.push('depths');
     }
 
-    return (depths.length === 0 ? 'this.program(' : 'this.programWithDepth(') + programParams.join(', ') + ')';
+    return 'this.program(' + programParams.join(', ') + ')';
   },
 
   useRegister: function(name) {
@@ -847,6 +863,14 @@ JavaScriptCompiler.prototype = {
     }
   },
 
+  contextName: function(context) {
+    if (this.useDepths && context) {
+      return 'depths[' + context + ']';
+    } else {
+      return 'depth' + context;
+    }
+  },
+
   quotedString: function(str) {
     return '"' + str
       .replace(/\\/g, '\\\\')
@@ -878,7 +902,7 @@ JavaScriptCompiler.prototype = {
       params: params,
       paramsInit: paramsInit,
       name: foundHelper,
-      callParams: ["depth0"].concat(params).join(", ")
+      callParams: [this.contextName(0)].concat(params).join(", ")
     };
   },