transfuse.js

Transfuse.js is a lightweight JavaScript dependency injection container. Although not required, the developer is encouraged to use this library in conjunction with a more robust AMD module loader (e.g. RequireJS).

Moderately complex JavaScript applications frequently contain shared objects that are referenced throughout the codebase. Transfuse.js provides the developer with a single container with which they can store and reference those objects throughout their application.

Additional Information

• Read a very concise summary of the concept of dependency injection here.
• Shared objects have their place, but at a certain point you should also be promoting “loose coupling” via PubSub (“publish / subscribe”) throughout your application with the help of additional libraries such as Postal.js.

Example Usage

Defining Dependencies

Dependencies are stored for later reference via the set() method.

define([
    'Dependency1',
    'Dependency2',
    'transfuse'
], function(Dependency1, Dependency2, transfuse) {

    var dependency1 = new Dependency1();
    var dependency2 = new Dependency2();

    transfuse.set(‘dependency1’, dependency1);
    transfuse.set(‘dependency2’, dependency2);

    /*
    Multiple dependencies can be stored with a single call to set() like so:
    transfuse.set({
        ‘dependency1’: dependency1,
        ‘dependency2’: dependency2
    });
    */

});

Referencing Dependencies

Requesting Specific Dependencies By Name

Once your transfuse dependency container has been setup, you can reference individual dependencies by name via the get() method.

define([
    ‘transfuse’
], function(transfuse) {

    var dependency1 = transfuse.get(‘dependency1’);

});

Extending an Object with Multiple Dependencies

Mix multiple dependencies with an object via the extend() method.

define([
    ‘transfuse’
], function() {

    transfuse.extend(this, [‘dependency1’, ‘dependency2’]);

    console.log(this.dependency1 instanceof Dependency1); // true
    console.log(this.dependency2 instanceof Dependency2); // true

});

Creating ‘Contexts’

Transfuse’s set(), get(), and extend() methods all share a single “sandbox” within which dependencies are defined and referenced. If you need a greater degree of segmentation, you can create additional sandboxes as shown below.

define([
    ‘Dependency3’,
    ‘transfuse’
], function(Dependency3, transfuse) {

    var dependency3 = new Dependency3();

    var other = transfuse.createContext(‘other’);
    other.set(‘dependency3’, dependency3);

});

Installation

Bower

$ bower install transfuse