Example: Adding and Removing Tabs

This example shows how to give TabView buttons for adding and removing tabs.

foo content

bar content

baz content

Note: be sure to add the yui3-skin-sam classname to the page's <body> element or to a parent element of the widget in order to apply the default CSS skin. See Understanding Skinning.

<body class="yui3-skin-sam"> <!-- You need this skin class -->

Plugin Template

In order to make these addons reusable, we can build them as plugins. This allows the option for multiple tabviews that mix and match functionality. To get started, we will first fill in a basic Plugin template. The NAME property is required to prefix events, classNames, et cetera. The NS is the namespace where the plugin will live on the host. This is where its API can be accessed (e.g. "node.addable.destroy()"). Adding the this._host alias provides a convenient way to get back to the TabView instance. Calling the superclass constructor kicks off the Base lifecycle, which will call the initializer.

var Addable = function(config) {
    this._host = config.host;
    Addable.superclass.constructor.apply(this, arguments);
};

Addable.NAME = 'addableTabs';
Addable.NS = 'addable';

Y.extend(Addable, Y.Plugin.Base, {
    initializer: function(config) {
    }
});

Addable Tab Plugin

To simplify adding new tabs, we are going to add a button that users can click and that will prompt them for some details regarding the new tab. The main task we are trying to accomplish is to add some HTML to the TabView, listen for clicks on the button, prompt the user for input, and update the tabs accordingly.

HTML Template

The first thing we need is a template for the markup to be generated. Adding this to the prototype allows separate customization for each TabView instance. For this example, we want it to look and feel like another Tab without actually being one.

Y.extend(Addable, Y.Plugin.Base, {
    ADD_TEMPLATE: '<li class="yui3-tab" title="add a tab">' +
                '<a class="yui3-tab-label yui3-tab-add">+</a></li>',

    initializer: function(config) {
    }
});

Adding the HTML

Now that we have a markup template, we will need to add it to the TabView somehow. The render phase is the appropriate moment to do so. Listening for the render event will give us access to that moment. Listening for after('render') ensure that the rendering has actually happened. Then we just need to find the tab list and, using the template, add the new item. The contentBox provides a Node that can be used to manage the TabView HTML.

Y.extend(Addable, Y.Plugin.Base, {
    ADD_TEMPLATE: '<li class="yui3-tab" title="add a tab">' +
                '<a class="yui3-tab-label yui3-tab-add">+</a></li>',

    initializer: function(config) {
        var tabview = this.get('host');
        tabview.after('render', this.afterRender, this);
    },

    afterRender: function(e) {
        var tabview = this.get('host');
        tabview.get('contentBox').one('> ul').append(this.ADD_TEMPLATE);
    }
});

Handling the Click

All that remains is to listen for clicks on the add button and prompt the user for the relevant Tab data. Again we can leverage the Node API, this time to delegate clicks on the add button. Stopping event propagation in our handler ensures that the event does not bubble any further, preventing the TabView from trying to handle it. To keep the example simple, a basic prompt is used to get the user input. This could be refined to use an Overlay or other custom control. The data is then handed off to TabView's add method.

Y.extend(Addable, Y.Plugin.Base, {
    ADD_TEMPLATE: '<li class="yui3-tab" title="add a tab">' +
                '<a class="yui3-tab-label yui3-tab-add">+</a></li>',

    initializer: function(config) {
        var tabview = this.get('host');
        tabview.after('render', this.afterRender, this);

        tabview.get('contentBox')
            .delegate('click', this.onAddClick, '.yui3-tab-add', this);
    },

    afterRender: function(e) {
        this.get('host').get('contentBox').one('> ul').append(this.ADD_TEMPLATE);
    },

    getTabInput: function() {
        return {
            label: window.prompt('label:', 'new tab'),
            content: window.prompt('content:', '<p>new content</p>'),
            index: Number(window.prompt('index:', this._host.size()))
        }
    },

    onAddClick: function(e) {
        e.stopPropagation();
        var tabview = this.get('host');
            input = this.getTabInput();
        tabview.add(input, input.index);
    }
});

Using the Plugin

Now we can go ahead and plug in our functionality. This can be during construction with the plugins attribute, or subsequently via the plug method.

var tabview = new Y.TabView({
    children: [{
        label: 'foo',
        content: '<p>foo content</p>'
    }, {
        label: 'bar',
        content: '<p>bar content</p>'
    }, {
        label: 'baz',
        content: '<p>baz content</p>'
    }],
    plugins: [Addable]
});

// or
// tabview.plug(Addable);

Removeable Tabs Plugin

The process for creating a removeable plugin for TabView is very similar. The full source is provided below.

var Removeable = function(config) {
    Removeable.superclass.constructor.apply(this, arguments);
};

Removeable.NAME = 'removeableTabs';
Removeable.NS = 'removeable';

Y.extend(Removeable, Y.Plugin.Base, {
    REMOVE_TEMPLATE: '<a class="yui3-tab-remove" title="remove tab">x</a>',

    initializer: function(config) {
        var tabview = this.get('host'),
            cb = tabview.get('contentBox');

        cb.addClass('yui3-tabview-removeable');
        cb.delegate('click', this.onRemoveClick, '.yui3-tab-remove', this);

        // Tab events bubble to TabView
        tabview.after('tab:render', this.afterTabRender, this);
    },

    afterTabRender: function(e) {
        // boundingBox is the Tab's LI
        e.target.get('boundingBox').append(this.REMOVE_TEMPLATE);
    },

    onRemoveClick: function(e) {
        e.stopPropagation();
        var tab = Y.Widget.getByNode(e.target);
        tab.remove();
    }
});

Complete Example Source