Monday, October 21, 2013

Create and Retrieve Nested Objects with MooTools

One argument that's been lodged by many is that MooTools doesn't encourage the use of namespaces for classes.  The Dojo Toolkit does employ namespaces and provides two helpful functions for working with them:  dojo.getObject and dojo.setObject.  These methods allow for setting and getting of nested objects via strings.  I've ported this functionality MooTools so you can create and retrieve nested objects quickly!

The MooTools JavaScript

Here goes the magic, slightly modified from Dojo:
(function() {

 // Utility method to get and set objects that may or may not exist
 var objectifier = function(splits, create, context) {
  var result = context || window;
  for(var i = 0, s; result && (s = splits[i]); i++) {
   result = (s in result ? result[s] : (create ? result[s] = {} : undefined));
  }
  return result;
 };

 // Creates an object if it doesn't already exist
 Object.extend("place", function(name, value, context) {
  var splits = name.split("."), s = splits.pop(), result = objectifier(splits, true, context);
  return result && s ? (result[s] = value) : undefined;
 });

 // Retrieves an object if not already present
 Object.extend("retrieve", function(name, create, context) {
  return objectifier(name.split("."), create, context);
 });

 // Checks to see if the object exists
 Object.extend("exists", function(name, context) {
  return Object.retrieve(name, false, context) !== undefined;
 });

})();
Both methods use a root method for parsing the string and finding the object, if it exists.  The place method creates the object, accepting the object name, value, and context (base object), creating the object as desired:
// Creates my.namespace.MyClass
Object.place("my.namespace.MyClass", {
 name: "David"
});
// my.namespace.MyClass.name = "David"

// Creates some.existing.objecto.my.namespace.MyClass
Object.place("my.namespace.MyClass", {
 name: "David"
}, some.existing.objecto); // Has to be an existing object
Likewise, the retrieve method searches for the object, and optionally may create it:
// Get an object
Object.retrieve("my.namespace.MyClassToo");

// Try to find an object, create it if it doesn't exist
Object.retrieve("my.namespace.MyClassThree", true);
As a bonus, I've also thrown in an exists method to check for the existence of an object:
Object.exists("my.namespace.MyClassToo"); // returns TRUE or FALSE
Woohoo!  These are some really nice utility methods to have around if you're looking to work with dynamic objects and namespaces!