dispenser

dispenser

Another approach of IoC/Dependency Injection for JavaScript

Install with npm

currently not in npm (need a name, meh)

Why?

Because I like the idea of IoC and I like JavaScript.

Design and Ideas

Dispenser does not use magical getters or setters but offers some simple(?) functions to register and retrieve services. Services can be configured using plain values or by defining a factory which may consume other services.

Factorys are only executed once. They are usefull for lazy instanciating of services. The factory is called when the service is requested for the first time. The result is cached and this cache will be used for furter requests.

Usage

var dispenser = require( 'dispenser' )

register a service

dispenser.register('the_answer', 42)

register a service via a factory

dispenser.factory('give_answer', ['the_answer'], function(a) {
    return 'The answer to life the universe and everything is ' + a;
})

or use the short form

dispenser.factory('give_answer', function(the_answer) {
    return 'The answer to life the universe and everything is ' + the_answer;
})

retrieve a service

dispenser.inject(['give_answer'], function(txt) {
    console.log(txt)
})

or use the short form

dispenser.inject(function(give_answer) {
    console.log(give_answer)
})

this works the same way for more complex data:

dispenser.register('$config', require('./config'))

dispenser.factory('$dbm', function($config) {
    return DatabaseDriver.connect($config.db.uri)
})

function UserController($config, $dbm) {
    if(!(this instanceof UserController)) {
        return new UserController($config, $dbm)
    }
}

dispenser.factory('UsrCtrl', UserController)

API

Thats what I'd call the "public API" of dispenser. It exposes some more functions but they aren't made for public use.

dispenser.register(name, value)

• name the services name
• value the value you want to store as a service

dispenser.factory(name[, parameters], factory[, async])

• name the services name
• parameters (optional) Array of service names to use as arguments for the factoy. If omited dispenser tries to parse these names from the factory source.
• factory the factory function itself.
• async (optional) defines if the factory function is asynchronus. Defaults to false, if true, the last parameter given to factory will be a callback(err, service)

dispenser.inject([parameters ,] function)

• parameters (optional) Array of service names to use as arguments for the function. If omited dispenser tries to parse these names from the functions source.
• function the funciton that should be called with the services as arguments.

The MIT License (MIT)

Copyright (c) 2013 Mark Schmale

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.