Filtering the Collection in Backbone.js

 

Introduction

This article explains the filtering of the collection in backbone.js. The goal here is to create a collection in which a filer function is provided for filtering the collection. The filter function is SetFilter(function() {}), it is set as the given function as the filter.

Use the following procedure to create the sample:

  1. Create a Web application:
  • Start Visual Studio 2013.
  • From the Start window select "New Project".
  • Select "Installed" -> "Visual C#" -> "Visual Studio 2012"and select "Empty web application".

Select Web application

  • Click the "OK" button.
  1. Now add an HTML page to the project.
  • In the Solution Explorer.
  • Right-click on the project and select "Add" -> "HTML Page".

Add HTML page

  • Change the Name of the page.

Change Name

  • Now click on the "Add" button.

Add the following code:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN"

          "http://www.w3.org/TR/html4/strict.dtd">

<html lang="en">

<head>

    <title>Backbone.js Filter List Example</title>

</head>

<body>

    <div id="mainContainer">

        <div id="contentContainer"></div>

    </div>

    <script>

        var myapp = {

            model: {},

            view: {},

            collection: {},

            router: {}

        }

    </script>

    <script id="list_container_tpl" type="text/template">

        <div class="grid_5 listContainer">

            <div class="box">

                <h2 class="box_head grad_colour">Tasks List</h2>

                <div class="sorting">

                    ShowList: <select id="taskSorting"><option value="0">Currently working on</option><option value="1">Completed Task</option></select>

                    <input class="search round_all" id="searchTask" type="text" value="">

                </div>

                <div class="block">

                    <ul id="taskList" class="list"></ul>

                </div>

            </div>

        </div>

    </script>

    <script id="task_item_tpl" type="text/template">

        <li class="task">

            <h4 class="name searchItem"><%= name %></h4>

        </li>

    </script>

    <script type="text/javascript" src="libs/jquery-1.6.2.min.js"></script>

    <script type="text/javascript" src="libs/underscore-min.js"></script>

    <script type="text/javascript" src="libs/backbone.js"></script>

    <script type="text/javascript" src="js/model.js"></script>

    <script type="text/javascript" src="js/collection.js"></script>

    <script type="text/javascript" src="js/views/view.tasksContainer.js"></script>

    <script type="text/javascript" src="js/views/view.tasksItem.js"></script>

    <script type="text/javascript" src="js/router.js"></script>

    <script>

        Backbone.history.start();

    </script>

</body>

</html>

 

  1. Now add a new folder in the project in which we add the JavaScript file:
  • In the Solution Explorer.
  • Right-click on the project and select "Add" -> "New Folder".
  • Set the folder name as "js".
  • Now add three Js files Model, router, collection.

Add javascript

  • Right-click on the folder and select "Add" -> "New Item" -> "JavaScript".

In the "Collection.js" script file add the following code:

myapp.collection.Tasks = Backbone.Collection.extend({

    currentStatus: function (status) {

        return _(this.filter(function (data) {

            return data.get("completed") == status;

        }));

    },

    search: function (letters) {

        if (letters == ""return this;

        var pattern = new RegExp(letters, "gi");

        return _(this.filter(function (data) {

            return pattern.test(data.get("name"));

        }));

    }

});

myapp.collection.tasks = new myapp.collection.Tasks([tasks1, tasks2, tasks3, tasks4]); 

 In the Model.js file Add the following Code:

myapp.model.Tasks = Backbone.Model.extend({

    default: {

        completed: 0,

        name: ""

    },

    url: "/js/libs/fixtures/task.json"

});

var tasks1 = new myapp.model.Tasks({

    completed: 0,

    name: "Dishis Ready for serve"

}

);

var tasks2 = new myapp.model.Tasks({

    completed: 1,

    name: "Decoration have done"

}

);

var tasks3 = new myapp.model.Tasks({

    completed: 0,

    name: "Do the laundry"

}

);

var tasks4 = new myapp.model.Tasks({

    completed: 1,

    name: "Vacuuming the carpet"

}

);

 

In the "router.js" script file add the following code:

 

 

myapp.router.Tasks = Backbone.Router.extend({

    routes: {

        """list",

    },

    list: function () {

        this.listContainerView = new myapp.view.TasksContainer({

            collection: myapp.collection.tasks

        });

        $("#contentContainer").append(this.listContainerView.render().el);

        this.listContainerView.sorts()

    }

});

myapp.router.tasks = new myapp.router.Tasks;

 

  1. Now execute the application, it will look like this:

Outputscreen

Select the Task type from the drop down list; it changes depending on the selection:

Filter collection


Change Data on selection 


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