node package manager
We need your input. Help make JavaScript better: Take the 2017 JavaScript Ecosystem survey »

b3nd

codecov

b3nd

knockout-style bindings for Backbone models and views

(pronounced "bend" — The 3 is for the 3 "b"s in Backbone bindings.)

installation:

npm install --save b3nd

requirements

b3nd has only been tested when bundled with webpack and when run on evergreen browsers.

usage:

const b3nd = require('b3nd');

bind.view binds your model's data to DOM elements call bind with your view to bind your view to your model's change events:

const MyView = Backbone.View.extend({
  initialize : function () {
    b3nd(this); // where the magic happens 
  },
});

This above code binds your model to your view's DOM elements. To specify how your view should consume the binding, specify a data-model-bind attribute in the element(s) of your view. The syntax of the data-model-bind attribute is that of of a javascript object, but without the outer braces. The key is the name of the binding, and the value is a javascript expression. The binding expression is evaluated in the global scope and has access to a variable called "model" that contains the values of the model to which the element is bound. For example:

<div>My full name is:
  <span data-model-bind='text : model.firstName'>
    <span data-model-bind='text : model.lastName, visible : model.lastName'>
    <span data-model-bind='visible : !model.lastName'>Oops, last name is not set</span>
  </span>
</div>

In this example, whenever firstName or lastName changes in your model, the DOM will automatically update according to the 'text' binding. If lastName is falsy, then "Oops, last name is not set" is shown. For a list of pre-defined bindings, see the bindings object below.

computeds can be specified as a property of the view on which bind is called:

var MyView = Backbone.View.extend({
  computed : {
    fullName : function (attributes) {
      return attributes.firstName + " " + attributes.lastName;
    }
  },
  initialize : function () {
    b3nd(this);
  },
});

The computed callback is passed the result of calling toJSON on the model.

the result of computeds can be referenced in the binding data on a global called computed:

<div data-model-bind='text : computed.fullName'></div>

API

a call to b3nd returns an instance of the internal class B3ndContext, which has the following methods:

  • on: enable the bindings until off is called
  • off: disable the bindings until on is called
  • forceUpdate: force the bindings to update immediately