backbone.mutators.js 

/*! Backbone.Mutators - v0.3.0
------------------------------
Build @ 2012-05-19
Documentation and Full License Available at:
http://asciidisco.github.com/Backbone.Mutators/index.html
git://github.com/asciidisco/Backbone.Mutators.git
Copyright (c) 2012 Sebastian Golasch <public@asciidisco.com>

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.*/

(function (root, define, require, exports, module, factory, undef) {
    'use strict';
    
    if (typeof exports === 'object') {

Node. Does not work with strict CommonJS, but only CommonJS-like enviroments that support module.exports, like Node.

 
        module.exports = factory(require('underscore'), require('backbone'));
    } else if (typeof define === 'function' && define.amd) {

AMD. Register as an anonymous module.

 
        define(['underscore', 'backbone'], function (_, Backbone) {

Check if we use the AMD branch of Back

 
            _ = _ === undef ? root._ : _;
            Backbone = Backbone === undef ? root.Backbone : Backbone;
            return (root.returnExportsGlobal = factory(_, Backbone, root));
        });
    } else {

Browser globals

 
        root.returnExportsGlobal = factory(root._, root.Backbone);
    }

Usage:

Note: This plugin is UMD compatible, you can use it in node, amd and vanilla js envs

Vanilla JS:

Node: var _ = require('underscore'); var Backbone = require('backbone'); var Mutators = require('backbone.mutators');

AMD: define(['underscore', 'backbone', 'backbone.mutators'], function (_, Backbone, Mutators) { // insert sample from below return User; });

var User = Backbone.Model.extend({ mutators: { fullname: function () { return this.firstname + ' ' + this.lastname; } },

defaults: { firstname: 'Sebastian', lastname: 'Golasch' } });

var user = new User(); user.get('fullname') // returns 'Sebastian Golasch' user.toJSON() // return '{firstname: 'Sebastian', lastname: 'Golasch', fullname: 'Sebastian Golasch'}'

 
}(this, this.define, this.require, this.exports, this.module, function (_, Backbone, root, undef) {
    'use strict';

check if we use the amd branch of backbone and underscore

 
    Backbone = Backbone === undef ? root.Backbone : Backbone;
    _ = _ === undef ? root._ : _;

extend backbones model prototype with the mutator functionality

 
    var Mutator     = function () {},
        oldGet      = Backbone.Model.prototype.get,
        oldSet      = Backbone.Model.prototype.set,
        oldToJson   = Backbone.Model.prototype.toJSON;

override get functionality to fetch the mutator props

 
    Mutator.prototype.get = function (attr) {
        var isMutator = this.mutators !== undef;

check if we have a getter mutation

 
        if (isMutator === true && _.isFunction(this.mutators[attr]) === true) {
            return _.bind(this.mutators[attr], this.attributes)();
        }

check if we have a deeper nested getter mutation

 
        if (isMutator === true && _.isObject(this.mutators[attr]) === true && _.isFunction(this.mutators[attr].get) === true) {
            return _.bind(this.mutators[attr].get, this.attributes)();
        }

        return oldGet.call(this, attr);
    };

override set functionality to set the mutator props

 
    Mutator.prototype.set = function (key, value, options) {
        var isMutator   = this.mutators !== undef,
            ret         = null,
            attrs       = null,
            attr        = null;

seamleassly stolen from backbone core check if the setter action is triggered using key <-> value or object 

        if (_.isObject(key) || key === null) {
            attrs = key;
            options = value;
        } else {
            attrs = {};
            attrs[key] = value;
        }

check if we have a deeper nested setter mutation

 
        if (isMutator === true && _.isObject(this.mutators[key]) === true) {

check if we need to set a single value

 
            if (_.isFunction(this.mutators[key].set) === true) {
                ret = _.bind(this.mutators[key].set, this)(key, attrs[key], options, _.bind(oldSet, this));
            }
        }

        if (value === undef && options === undef) {
            _.each(attrs, _.bind(function (attr, attrKey) {
                if (isMutator === true && _.isObject(this.mutators[attrKey]) === true) {

check if we need to set a single value

 
                    if (_.isFunction(this.mutators[attrKey].set) === true) {
                        if (options === undef || (_.isObject(options) === true && options.silent !== true && (options.mutators !== undef && options.mutators.silent !== true))) {
                            this.trigger('mutators:set:' + attrKey);
                        }
                        ret = _.bind(this.mutators[attrKey].set, this)(attrKey, attr, options, _.bind(oldSet, this));
                    }
                }
            }, this));
        }

        if (ret !== null) {
            return ret;
        }

        return oldSet.call(this, key, value, options);
    };

override toJSON functionality to serialize mutator properties

 
    Mutator.prototype.toJSON = function () {

fetch ye olde values

 
        var attr = oldToJson.call(this);

iterate over all mutators (if there are some)

 
        _.each(this.mutators, _.bind(function (mutator, name) {

check if we have some getter mutations (nested or )

 
            if (_.isObject(this.mutators[name]) === true && _.isFunction(this.mutators[name].get)) {
                attr[name] = _.bind(this.mutators[name].get, this.attributes)();
            } else {
                attr[name] = _.bind(this.mutators[name], this.attributes)();
            }
        }, this));

        return attr;
    };

extend the models prototype

 
    _.extend(Backbone.Model.prototype, Mutator.prototype);

make mutators globally available under the Backbone namespace

 
    Backbone.Mutators = Mutator;
    return Mutator;
}));