timoxley / ampersand-registry

Global model registry for tracking instantiated models across collections.

ampersand-registry

Global model registry for tracking instantiated models accross collections.

This isn't necessary for most apps, but sometimes it's useful to create a global registry of all or a subset of instantiated models in your application. This can be useful when realtime applications where you're getting incoming events with IDs and model types and need some global way to look up models in your application.

The code is quite short and simple it's only ~50 lines. It may be easiest to just read the code for documetation. But some examples/explanations are included below.

Part of the Ampersand.js toolkit for building clientside applications.

install

npm install ampersand-registry

browser support

example

var Registry = require('ampersand-registry');
var Model = require('ampersand-model');

// a singleton model registry
window.registry = new Registry();

// then whenever we're defining models for our application
// if we're using ampersand-model or it's lower level cousin
// ampersand-state we can pass it the registry as part of the
// definition.

var MyModel = Model.extend({
    type: 'user',
    props: {
        name: 'string'
    },
    // Pass the registry you want all the instances of this model
    // to be included in.
    registry: window.registry

    // can also be a function in case it's not defined yet
    registry: function () {
        return window.registry;
    } 
});

After doing this all instantiated models will be put into the registry based on their type property and be removed when destroyed.

Then the registry can be used to look up models as follows:

// explicitly storing a model
// (if you declare them in your models this isn't necessary) 
// this will use the models `type`, `getId`, and `namespace` 
// properties to store this accordingly.
registry.store(model);

// get a model
registry.lookup('{{model type}}', '{{ model id }}', '{{ optional namespace }}');

// remove a stored model from the store by type, id and optionally namespace
registry.remove('{{model type}}', '{{ model id }}', '{{ optional namespace }}');

// de-reference all models
registry.clear();

credits

If you like this follow @HenrikJoreteg on twitter.

license

MIT