add text_area support

lib/form.js

@@ -45,6 +45,23 @@ Crayon.Form = {
       return tag("input",html_opt);
    },
 
+   /**
+    * Returns an textarea tag tailored for accessing a specified attribute.
+    * @param {Object} doc JSON document to bind.
+    * @param {String} path JSON member path seperated by "-".
+    * @param [Object] options tag attribute options.
+    */
+   text_area : function(doc, path, options){
+      var val = Crayon.Form._getValueFromPath(doc, path);
+      // html options
+      var html_opt = Crayon.extend({
+         id : path,
+         name: path
+      }, options);
+      html_opt["type"] = "text";
+      return content_tag("textarea", val || "", html_opt);
+   },
+
    /**
     * Returns a set of select tags for date selection.
     * @param {String} date the default selected value.

spec/spec.form.js

@@ -67,6 +67,23 @@ JSpec.describe("form",  function(){
       });
    });
 
+   describe("text_area", function(){
+      it("should return area tag bound to doc.a.b.c", function(){
+         var doc = {
+            a: {
+               b: {
+                  c: "foo"
+               }
+            }
+         };
+         var result = text_area(doc, "a-b-c");
+         expect(result).should(match, /name="a-b-c"/);
+         expect(result).should(match, /id="a-b-c"/);
+         expect(result).should(match, /\>foo\<\/textarea\>/);
+      });
+   });
+
+
    describe("date_select", function(){
       it("should return select tags bound to doc.a.b.c", function(){
          var doc = {