Start working on the runtime

2010-11-25 23:32:32 -08:00
parent b401fc388b
commit 3b0970d8aa
2 changed files with 121 additions and 0 deletions
@@ -0,0 +1,120 @@
+if(exports) {
+  var inspect = function(obj) {
+    require("sys").print(require("sys").inspect(obj) + "\n");
+  }
+  var Handlebars = {};
+  Handlebars.AST = require("handlebars/ast");
+  Handlebars.Visitor = require("handlebars/jison_ext").Visitor;
+}
+
+Handlebars.Context = function(data, fallback) {
+  this.data     = data;
+  this.fallback = fallback;
+};
+
+Handlebars.Context.prototype = {
+  isContext: true,
+
+  clone: function() {
+    var context = new Handlebars.Context;
+    context.data = this.data;
+    context.fallback = this.fallback;
+    return context;
+  },
+
+  evaluate: function(path, stack) {
+    var context = this.clone();
+    var depth = path.depth, dig = path.dig, parts = path.parts;
+
+    if(depth > stack.length) { context.data = null; }
+    else if(depth > 0) { context = stack[stack.length - depth].clone(); }
+
+    for(var i=0,l=parts.length; i<l && context.data != null; i++) {
+      context.data = context.data[parts[i]];
+    }
+
+    if(parts.length === 1 && context.data === undefined) {
+      context.data = context.fallback[parts[0]];
+    }
+
+    return context;
+  }
+};
+
+Handlebars.K = function() { return this; };
+
+Handlebars.proxy = function(obj) {
+  var Proxy = this.K;
+  Proxy.prototype = obj;
+  return new Proxy;
+}
+
+Handlebars.Runtime = function(context, fallback, stack) {
+  this.stack = stack || [];
+  this.buffer = "";
+
+  var newContext = this.context = new Handlebars.Context;
+
+  if(context.isContext) {
+    newContext.data     = context.data;
+    newContext.fallback = context.fallback;
+  } else {
+    newContext.data     = context;
+    newContext.fallback = fallback || {};
+  }
+};
+
+Handlebars.Runtime.prototype = {
+  accept: Handlebars.Visitor.prototype.accept,
+
+  ID: function(path) {
+    return this.context.evaluate(path, this.stack);
+  },
+
+  STRING: function(string) {
+    return { data: string.string };
+  },
+
+  program: function(program) {
+    var statements = program.statements;
+
+    for(var i=0, l=statements.length; i<l; i++) {
+      this.accept(statements[i]);
+    }
+  },
+
+  mustache: function(mustache) {
+    var idObj  = this.accept(mustache.id);
+    var params = mustache.params;
+
+    for(var i=0, l=params.length; i<l; i++) {
+      params[i] = this.accept(params[i]).data;
+    }
+
+    if(toString.call(idObj.data) === "[object Function]") {
+      this.buffer = this.buffer + idObj.data.apply(this.wrapContext(), params);
+    } else {
+      if(params.length) { throw new Error(mustache.id.parts.join("/") + " is not a Function, so you cannot have Function parameters"); }
+      this.buffer = this.buffer + idObj.data;
+    }
+  },
+
+  content: function(content) {
+    this.buffer += content.string;
+  },
+
+  wrapContext: function() {
+    var proxy     = Handlebars.proxy(this.context.data);
+    var context   = proxy.__context__ = this.context;
+    var stack     = proxy.__stack__   = this.stack.slice(0);
+
+    proxy.__get__ = function(path) {
+      return context.evaluate(path, stack).data
+    };
+  }
+
+}
+
+if(exports) {
+  exports.Runtime = Handlebars.Runtime;
+}