node-lube

Simple dependency injector for node using Promises. Lifecycle of resolved components are handled by client via nesting promises or you can use a lifecycleContainer parameter to hold references to already resolved components. lube supports simple dependency checking between components, i.e. you can specify which components are required and check will fail with they are not me.

Installation

npm install lube --save

Test

npm test

Usage

Registering

To register a component:

var component = require('./mycomponent');
var container = require('lube')();

container
    .use(component())   //add component to the container
    .check();           //check that all dependencies have been met

We can even register multiple components at once:

var component_a = require('./mycomponent'),
    component_b = require('./my-other-component');
    
var container = require('lube')();

container
    .use([component_a(),component_b()])   //add components to the container
    .check();           //check that all dependencies have been met

If we want to register component with the same name as already registered:

var component_a = require('./mycomponent'),
    component_same_name_as_a = require('./my-other-component-with-same-name');
    
var container = require('lube')();

container
    .use(component_a())
    .use(component_same_name_as_a())    //this will throw
    .use(component_same_name_as_a(), true)    //this will replace component_a 
    .check();           //check that all dependencies have been met

Resolving

To resolve singe component:

container.component('name')
    .then(function(resolvedComponent){
       //Profit! 
    });

To resolve all components matching regex:

//imagine we registered components route/a, route/b, system/x
container.allComponents(/^route\/.*/)
    .then(function(resolvedComponents){
       //resolvedComponents cotains route/a, route/b components but doesn't contain system/x
    });

Component definition

The box-standard component looks like this:

module.exports = function () {
    //returns component definition
    return {
        
        //req is an array of required components names
        req: [],
        
        //name of this component
        provides: 'config',
        
        //context (this) when calling providePromise
        //container if it's undefined 
        context: undefined,
        
        //methood that returns promise that resolves component
		providePromise: function(container)
        {
            //this is container as well
            
			return Promise.resolve({});  //returns promise that resolves the component
		}
    }
}

API

For complete API documentation see lube.js.

Release History

• 0.1.0 Initial release
• 0.2.0 Some more renaming from first attempt
• 0.3.0 Lifecycle support