accessorize.js makes it easy to convert plain javascript 'properties' into fancy-ass-observable-accessor-methods! Simply call accessorize() with your plain-old-javascript-object and get back a super-charged wrapped version.

Unimportant Note: Actually you could name accessorize anything you want since it's packaged as an AMD Module

Accessors

Accessorized accessor methods will be familiar to anyone who has used JQuery:

Getter: var foo = obj.propertyName()

Setter: obj.propertyName(newValue)

But wait! There's more!

Change Notifications (AKA: Observables)

In addition to the lovely accessor semantics, you'll also get change notification too!

var obj = accessorize({
    propertyOne : "value",
    propertyTwo : "another value"
});

obj.propertyOne.subscribe(function(newValue){
    alert("Property One changed to " + newValue);
});

obj.propertyOne("some new value"); //What do you think happens now?

Array Accessors

The array accessors have a couple of special powers themselves.

In addition to the normal getter/setter behavior of the regular accessors, array accessors offer indexing variations of the getters and setters:

var obj = accessorize({
    arrayProperty = ["hello", "world"]
});

//indexing getter
var item = obj.arrayProperty(1);
alert(item); // alerts: "world"

//indexing setter
obj.arrayProperty(0,"goodbye");
alert(obj.arrayProperty(0)); // alerts: "goodbye"

Finally, array accessors surface the standard array methods directly on the accessor object itself. This lets array accessors be used a lot like an array would be in many cases. It also provides change notification if any of the mutator methods are called.

A not-really-all-that-exciting example:

//You can do this:

var combined = obj.arrayProperty.concat([1,2,3]);

//instead of this:

var combined = obj.arrayProperty().concat([1,2,3]);

A more exciting example:

The mutator methods are more interesting, since we get change notifications when they are called.

var obj = accessorize({
    arrayProperty = ["hello", "world"]
});

obj.arrayProperty.subscribe(function(){ alert("Changed!"); });

obj.arrayProperty.sort() // alerts: "Changed!"

The following methods are promoted to the accessor:

Causes Change Notification:

• pop
• push
• reverse
• shift
• sort
• splice
• unshift

No Change to Property Value:

• concat
• join
• slice
• indexOf *
• lastIndexOf *

* These methods are not natively provided by some browsers (IE up to 8). When they are not available, they are not promoted; but if they are patched in with a polyfill prior to accessorizing an object they will be promoted.

Setter Chaining

Setter calls can be chained, enabling nicely formatted chunks of code:

var person = accessorize({
    addresses : [],
    firstName : "",
    lastName : "",
    favoriteColor : ""
});

//Here it is, beautiful assignment blocks!
person
    .firstName("Joe")
    .lastName("Blow")
    .addresses(["123 Any Street", "58 Ave. Q"])
    .favoriteColor("Red");

//Wasn't that nice?

Underscore.js Integration

Underscore integration opens up a whole universe of helpful functionality on your data. See: underscore.js

If underscore is passed into an accessor it will return an underscore wrapped instance of the property value:

obj.arrayProperty(_).pluck('blah')

If underscore.string is loaded:

obj.stringProperty(_).chain().trim().capitalize().value()

Also, if the accessor is an Array accessor, you can retrieve an underscore wrapped instance at a given index:

obj.arrayProperty(1,_).trim()

Identify Accessorized Objects

isAccessorized() is available so that you can identify which of your objects have been accessorized.

var source = {
    propertyOne : "value",
    propertyTwo : "another value"
}

if (accessorize.isAccessorized(source)) {
    alert("This doesn't happen!");
}

var obj = accessorize(source);

if (accessorize.isAccessorized(obj)) {
    alert("But this does!");
}

If an object is accessorized, isAccessorized() returns an object with a kind property: 'object' if the accessorized object is a wrapped object, 'accessor' if it is an accessor.

JSON Serialization

Care has been taken, and toJSON() methods written, to ensure that your accessorized objects will serialize to JSON like you'd expect.

var person = accessorize({
    addresses : ["123 any st.", "345 another ave."],
    firstName : "Joe",
    lastName : "Blow"
});

console.log(JSON.stringify(person))
//{"addresses":["123 any st.","345 another ave."],"firstName":"Joe","lastName":"Blow"}

"Why Accessor Methods? I thought ES5 has Properties already."

Two main reasons:

1. Accessorize has what devs need, now, even in non-ES5 environments.
2. The "JQuery-Style" Accessor Methods not only provide nice getter/setter syntax, but they also provide a nice place to hange meta-data and functions. Things like our subscribe() method have a nicer home than they could otherwise.

LICENSE

This software is licensed under the "MIT License":

Copyright (c) 2011 Brendan Erwin and contributors.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.