Rivets.js

Rivets.js is a declarative data binding facility that plays well with existing frameworks such as Backbone.js, Spine.js and Stapes.js. It aims to be lightweight (1.4KB minified and gzipped), extensible, and configurable to work with any event-driven model.

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Describe your UI in plain HTML using data attributes:

<div id='auction'>
  <h1 data-text='auction.title'></h1>
  <img data-src='auction.image_url'>
  <span data-text='auction.timeRemaining | time'></span>

  <div class='alert-box' data-show='auction.endingSoon'>
    <p>Hurry up! This auction is ending soon.</p>
  </div>

  <dl>
    <dt>Highest Bid:</dt>
    <dd data-text='auction.bid | currency'></dd>
    <dt>Bidder:</dt>
    <dd data-text='auction.bidder'></dd>
  </dl>

  <dl>
    <dt>Bids Left:</dt>
    <dd data-text='user.bidCount'></dd>
  </dl>
</div>

Then tell Rivets.js what model(s) to bind to it:

rivets.bind($('#auction'), {auction: auction, user: currentUser});

Configure

Use rivets.configure to configure Rivets.js for your app. There are a few handy configuration options, such as setting the data attribute prefix and adding formatters that you can pipe binding values to, but setting the adapter is the only required configuration since Rivets.js needs to know how to observe your models for changes as they happen.

Adapter

Rivets.js is model interface-agnostic, meaning it can work with any event-driven model by way of defining an adapter. An adapter is just an object that responds to subscribe, unsubscribe, read and publish. Here is a sample configuration with an adapter for using Rivets.js with Backbone.js.

rivets.configure({
  adapter: {
    subscribe: function(obj, keypath, callback) {
      callback.wrapped = function(m, v) { callback(v) };
      obj.on('change:' + keypath, callback.wrapped);
    },
    unsubscribe: function(obj, keypath, callback) {
      obj.off('change:' + keypath, callback.wrapped);
    }
    read: function(obj, keypath) {
      return obj.get(keypath);
    },
    publish: function(obj, keypath, value) {
      obj.set(keypath, value);
    }
  }
});

Formatters

Formatters are simple one-way functions that mutate the incoming value of a binding. You can use them to format dates, numbers, currencies, etc. and because they work in a similar fashion to the Unix pipeline, the output of each feeds directly as input to the next one, so you can stack as many of them together as you like.

rivets.configure({
  formatters: {
    money: function(value){
      return accounting.formatMoney(value);
    },
    date: function(value){
      return moment(value).format('MMM DD, YYYY');
    }
  }
});

Prefix and data preloading

To prevent data attribute collision, you can set the prefix option to something like 'rv' or 'bind' so that data attributes are prefixed like data-rv-text.

Set the preloadData option to true or false depending on if you want the binding routines to run immediately after the initial binding or not — if set to false, the binding routines will only run when the attribute value is updated.

Extend

You can extend Rivets.js by adding your own custom data bindings (routines). Just pass rivets.register an identifier and a routine function. Routine functions take two arguments, el which is the DOM element and value which is the incoming value of the attribute being bound to.

So let's say we wanted a data-color binding that sets the element's colour. Here's what that might look like:

rivets.register('color', function(el, value){
  el.style.color = value;
});

Available bindings out-of-the-box

• data-text
• data-html
• data-value
• data-show
• data-hide
• data-enabled
• data-disabled
• data-checked
• data-unchecked
• data-selected
• data-[attribute]
• data-on-[event]

Usage Notes

Rivets.View and Rivets.Binding

The rivets.bind function returns a bound Rivets.View instance that you should hold on to for later. You may want to unbind it's listeners with view.unbind() and/or rebuild it's bindings with view.build(). You can also access the individual Rivets.Binding instances inside the view through view.bindings — this is useful for debugging purposes or if you want to unbind or manually set the value for certain bindings.

Iteration Binding

Even though a binding routine for each-item will likely be included in Rivets.js, you can use the data-html binding along with a set of formatters in the interim to do sorting and iterative rendering of collections (amongst other cool things).

<ul data-html="model.tags | sort | tagList"></ul>

Building and Testing

Before proceeding, make sure to run npm install so that you have all the development dependencies.

Building

Rivets.js uses grunt as the build tool. Run grunt from within the project root and it will compile + minify into /lib whenever the source file is saved. You can also run grunt build to rebuild the project manually.

Testing

Rivets.js uses Jasmine as the testing framework. You can run the tests by opening the test.html file.