#Entity Component System

Simple system to create and utilize objects in the right way.

##Create objects

var factory = require('ecos').factory;
var entityFactory = factory.create({
    props: ['x', 'y'],
    name: 'my_entity'
});

var entity = entityFactory.create();
console.log(entity);
{
    x: undefined,
    y: undefined,
    id: 0,
    type: 'my_entity'
}

##Get objects

var objects = require('ecos').objects;
var entity = objects.get(0);

console.log(entity);
{
    x: undefined,
    y: undefined,
    id: 0,
    type: 'my_entity'
}

##Ideas behind this library

• Each entity is stored in unified container ecos.objects and accessible by its id
• Entity should not have direct link to other entities. Parent entity store identificators of child entities instead
• To get child entity just use ecos.objects.get(childId);
• Since entities are stored only in one container then no memory leaks will occur when objects will be deleted
• Different entities can share same methods and extenders and inherit same behaviour without prototype inheritance

##Instalation

As npm package:

npm install ecos --save

As bower package:

bower install ecos --save

##Documentation

###Factory

To create an entity first you need to create a factory that will produce entities:

var factory = require('ecos').factory;
var entityFactory = factory.create(options);

####Options:

• name - factory identificator, required string
• props - list of entity properties that will be initialized with undefined, [ string ]
• methods - list of entity methods, all methods must be registered with factory.registerMethod, [ string ]
• extend - list of extenders that will be applied to entity, all extenders must be registered with factory.registerExtender, [ string ]
• presets - list of presets that will be applied to entity, all presets must be registered with factory.registerPreset. [ string ]
• default - list of entity properties with predefined values, will overwrite props options, { propName: propValue }
• custom - list of entity properties with predefined values, will overwrite props and default options, is entity with this set will be accessible through entityFactory.customEntity() call, { customEntityName: { propName: propValue } }

####Create basic entity: Will create entity with fields.

var factory = require('ecos').factory;
var entityFactory = factory.create({
    props: [ 'x', 'y' ],
    name: 'example'
});
entityFactory.create();

Result:

{
    type: 'example',
    x: undefined,
    y: undefined,
    id: 0
}

If you pass object with fields to entity constructor then factory will create entity with specified fields defined:

entityFactory.create({x: 100, y: 200});

Result:

{
    type: 'example',
    x: 100,
    y: 200,
    id: 0
}

####Create entity with method: Use factory.registerMethod to register method that can be assigned to entity:

factory.registerMethod('console', function(text){
    console.log(text);
});

var entityFactory = factory.create({
    methods: ['console'],
    name: 'example'
});
entityFactory.create();

Result:

{
    type: 'example',
    console: function
    id: 0
}

####Create entity with GETSET extender: This extender will create field with defined getter and setter.

var extenders = require('ecos').extenders;

factory.registerExtender('value-extender', {
    get: function(){
        return this._value;
    },
    set: function(val){
        this._value = val;
        console.log('Value set to ' + val);
    },
    name: 'value',
    type: extenders.GETSET
});

var entityFactory = factory.create({
    extend: ['value-extender'],
    name: 'example'
});

entityFactory.create();
entity.value = Math.random();

Result:

Value set to 0.758898114

If you wont specify get or set function in extender definition then resulting field wont have getter or setter defined.

####Create entity with FUNCTION extender: This extender will run custom function on object creation.

factory.registerExtender('function-extender', {
    type: extenders.FUNCTION,
    handler: function(thisObject){
        console.log('Creating ' + JSON.stringify(thisObject));
    }
});

var entityFactory = factory.create({
    extend: ['function-extender'],
    name: 'example'
});

entityFactory.create();

Result:

Creating {"type":"example", "id":0}