UPDATE

This is the same as the original plugin, but these modifications:

• Allow users to pass parameter to collection.fetch() when calling nextPage()
• resetPagination function to reset paging to first page again
• remove url function

backbone-pagination V0.9

This simple and lightweight (<1kb minified) pagination plugin for Backbone.js allows you to extend your Backbone.Collections with pagination functionality by modifying the collection's fetch url.

These three methods are introduced:

• loadPage(pageNumber)
• nextPage()
• previousPage()

A typical REST api call with backbone-pagination will look like this:

/sales?page=3&ipp=25

or with pretty set to true:

/sales/page/3/ipp/25

Backbone.PaginatedCollection is also provided as a convenience class. It extends Backbone.Collection and mixes in the methods described below.

Dependencies

The backbone-pagination plugin relies on

• Backbone (tested with Backbone.js v0.9.2, but should work with most other versions)
• Underscore.js
• jQuery (as it uses the $.param() function)

Using the Backbone.js plugin

If you are not using a module loading library you will want to include the source file into your webpage:

<script type='text/javascript' src='/js/lib/modules/backbone-pagination.js'></script>

If you are using a module loading library like Require.js you can simply add it to your collection's dependencies.

define(['app', 'plugins/backbone.pagination'], function(app) {
    // Your module code.
});

You probably want to make sure that the shim configuration is set correctly.

require.config({
    // Your path configuration goes here
    shim: {
        backbone: {
        deps: ['underscore', 'jquery'],
            exports: 'Backbone'
        },
        // Backbone.Pagination depends on Backbone.
        'plugins/backbone.pagination' : ['backbone']
    }
});  

Extending your collection

Extend your collection by calling the Backbone.Pagination.enablemethod:

var someCollection = Backbone.Collection.extend({
    initialize: function(option) {
        Backbone.Pagination.enable(this);
    }
});

The enable(collection, config) method takes an optional config parameter, that can be used to configure the paginator.

You can also just initialize Backbone.PaginatedCollection:

var paginatedCollection = new Backbone.PaginatedCollection({
    ipp: 10,
    page_attr: "page",
    ipp_attr: "per_page"
});

Define your own paginated collections by extending Backbone.PaginatedCollection:

var MyPaginatedCollection = function() {};

MyPaginatedCollection.prototype = _.extend({
    baseUrl: "/collection/"
}, Backbone.PaginatedCollection.prototype);

Configuring backbone.pagination

Configure the url params and items-per-page count at any time by setting the paginationConfig values:

// default configuration
someCollection.paginationConfig = {
    pretty:       false,  // use pretty url params instead of query params
  	ipp:          25,     // items per page
  	page_attr:    'page', // the query's page attribute
   	ipp_attr:     'ipp',  // the query's ipp attribute
   	fetchOptions: {}      // any options passed to the fetch() method
}

If the pretty attribute is set to true the resulting api call will result in /baseUrl/page/3/ipp/25 instead of /baseUrl?page=3&ipp=25.

The fetchOptions attribute holds options, that will be passed to the Backbone.Collection.fetch() method. For example, if paginationConfig.fetchOptions.add is set to true, then new items will be appended to the collection. false will replace the collection's items with any new items fetched. You can also define success and error callbacks. See the Backbone.Collection.fetch() method's documentation.

Providing a url() method

backbone.pagination overrides the Backbone.Collection.url method in order to append the pagination params. Instead of setting the url property you will have to introduce a baseUrl property.

API

After enabling pagination on your collection, the following methods and attributes become available:

• currentPage holds the last fetched page number. Do not modify this attribute. Instead call one of the following xxxPage() methods:
• loadPage(pageNumber) will fetch the page number specified
• nextPage() will fetch the next page
• previousPage() will fetch the previous page – or fetch the first page if a call to this method would result in a negative or zero page number
• url() pagination url method will produce a custom pagination url like /baseUrl?page=3&ipp=25 or /baseUrl/page/3/ipp/25 with pretty set to true
• baseUrl or baseUrl() you should specify either a baseUrl attribute or method that returns the collection's base url.
• paginationConfig see Configuring backbone.pagination

Example

This example uses require.js to define a module providing a sales collection of sale models.

define([
	// Application.
	'app',

	// Backbone.
	'backbone',

	// Plugins.
	'plugins/backbone.pagination',
],

// Map dependencies from above array.
function(app, Backbone) {

	// Create a new module.
	var Sales = {};

	// The basic **sales** model.
	Sales.Model = Backbone.Model.extend({

		// Sync with this api url.
		url: 'sales/sale/id'
	});

	// Default collection.
	Sales.List = Backbone.Collection.extend({

		// Use this model class for collection items.
		model: Sales.Model,

		// Sync with this api url.  This method is called baseUrl because,
		// the Backbone.Collection.url method will be overwritten by the
		// pagination module.
		baseUrl: function() {
			return app.api + 'sales/list/city/' + this.city;
		},

		initialize: function(options) {
			// Enable pagination.
			Backbone.Pagination.enable(this, {
				ipp: 10,
				fetchOptions: {
					add: true  // instead of replacing the collection's model items, append new items
				}
			});
		}
	});

	// Return the module for AMD compliance.
	return Sales;
});