jQuery Development: Your own Plugins Part II

Andres — Tue, 08 Dec 2009 23:26:16 +0000

Extending on my previous post jQuery development: Your own plugins , we now have to take a look into a more complex plugin as well as making greater use of both JavaScript’s built in Regular Expression objects and jQuery provided functionality.

For the purposes of this post, I’ll be extending on the previous plugin to readily handle more video services: Dailymotion, Megavideo & Vimeo as well as the already supported YouTube. Also, we’ll be adding an option to leave the link but make the video pop up in a modal box using ColorBox.

Okay enough intro…let’s code!

First, we’re going to start off with the basic structure of every jQuery plugin:

(function($){
    $.fn.videa = function(){
    }
})(jQuery)

Note: We use this format for the purpose of ease and using the familiar $ variable, however we can just do this.

jQuery.fn.videa = function(){
   //How ever, within here we can only use the jQuery object,
   // $ is undefined.
}

First we’re going to need the embed code for each service. This is readily
available on their websites as well as the format for their actual flv’s.
I’ve already done this below.

Note: I’ve made use of JSON. If you don’t know about this, read up here.

(function($){

    $.fn.videa= function(){

        var supportedSites = {
            'youtube' : '',
            'dailymotion': '',
            'megavideo': '',
            'vimeo'    : ''
        }

        var handle = {
            'youtube'    : ['watch?v=', 'v/'],
            'dailymotion': [/.*dailymotion.*\/video\/(.*?)_.*/, 'http://dailymotion.com/swf/$1'],
            'megavideo'  : ['?v=', 'v/'],
            'vimeo'      : [/.*vimeo.*\/(.*[0-9])/, 'http://vimeo.com/moogaloop.swf?clip_id=$1&server=vimeo.com&show_title=1&show_byline=1&show_portrait=0&color=00adef&fullscreen=1']
        }

Next, we’ll need to make use of each utility; this is something that will be used in nearly ALL your plugins. The reason why is because you want the plugin to affect more than one HTML element.

(function($){
    $.fn.videa= function(){
        // We're of course assuming the aforementioned json is here
        // ommited for the purposes of readability
      this.each(function(){
      })
})(jQuery)

Now, for our purposes we don’t actually need to instantiate a jQuery object per element – yet. All we need is the href and class attributes which are easily available via JavaScript’s native getAttribute function.

(function($){
    $.fn.videa= function(){
        // We're of course assuming the aforementioned json is here
        // ommited for the purposes of readability
      this.each(function(){
           var href    = this.getAttribute('href');
           var aClass  = this.getAttribute('class');
           var key     = href.match(/(http:\/\/www\.|http:\/\/|www\.|)(.*?)\.(\.com|\.*)/)[2];

          // we now have the base such as 'youtube' and 'vimeo' in key
          // check if we support it
          if( supportedSites[key] )
          {
          }
      })
})(jQuery)

Now I’ll explain the regex

The first bit:

This matches the http protocol with or without the www or just the www

‘(http:\/\/www\.|http:\/\/|www\.|)’

The second bit:
Simply grabs everything AFTER the http://www.

‘(.*?)’

The third bit:

This matches against any .com or .* extension

‘\.(\.com|\.*)’

The rest is rather straight forward and can be explained in code comments.

// Check if the site is supported
if( supportedSites[key] )
            {
               // Construct properly url to the flv
               if( href.indexOf('http://www.') == -1 )
                        href = 'http://www.' + href.replace('www.', '');

                // Check if we want a modal box
                if( aClass.indexOf('modal') > -1 )
                {
                    // Bind to the click and fire off colorbox
                    $(this).click(function(){
                        $.fn.colorbox({
                            html: supportedSites[key].replace(/\[URL\]/ig, href.replace(handle[key][0], handle[key][1])) ,
                            open:true
                        });
                                return false;
                     })
                }else{
                    // We don't want a modal box so just do the html
                    $(this).before(supportedSites[key].replace(/\[URL\]/ig, href.replace(handle[key][0], handle[key][1]))).remove();
                }

Note: jQuery is a jackhammer, sometimes all we have is nails.

That’s the plugin broken down into the important sections. The end result is as expected. Everything which has a videa class is converted. The modal class is optional (it creates a link that opens a modal box with your video).

As for plugin development, once you understand DOM and the entire jQuery API, you can pretty much make anything you can come up with. JavaScript support is strong and growing.

The Entire plugin below:

(function($){

    $.fn.embeddedables = function(){

        var supportedSites = {
            'youtube' : '',
            'dailymotion': '',
            'megavideo': '',
            'vimeo'    : ''
        }

        var handle = {
            'youtube'    : ['watch?v=', 'v/'],
            'dailymotion': [/.*dailymotion.*\/video\/(.*?)_.*/, 'http://dailymotion.com/swf/$1'],
            'megavideo'  : ['?v=', 'v/'],
            'vimeo'      : [/.*vimeo.*\/(.*[0-9])/, 'http://vimeo.com/moogaloop.swf?clip_id=$1&server=vimeo.com&show_title=1&show_byline=1&show_portrait=0&color=00adef&fullscreen=1']
        }

        // Looad in this element for all a tags
        this.each(function(){

            var href   = this.getAttribute('href');
            var aClass = this.getAttribute('class');
            var key = href.match(/(http:\/\/www\.|http:\/\/|www\.|)(.*?)\.(\.com|\.*)/)[2];

            if( supportedSites[key] )
            {
               if( href.indexOf('http://www.') == -1 )
                        href = 'http://www.' + href.replace('www.', '');

                if( aClass.indexOf('modal') > -1 )
                {
                    $(this).click(function(){
                        $.fn.colorbox({
                            html: supportedSites[key].replace(/\[URL\]/ig, href.replace(handle[key][0], handle[key][1])) ,
                            open:true
                        });
                                return false;
                     })
                }else{
                    $(this).before(supportedSites[key].replace(/\[URL\]/ig, href.replace(handle[key][0], handle[key][1]))).remove();
                }
            }

        });

    }

})(jQuery)

jQuery development: Your own plugins

Andres — Mon, 16 Nov 2009 17:32:19 +0000

Often there is a need for functionality that goes above jQuery’s core set of methods, there are a host of plugins which can be used to attain this functionality. Such as ColorBox when a modal box is needed or jFlow for a basic gallery. However, sometimes these plugins cannot perform exactly the way we need them to without attacking the plugin’s source and in the end causing a fair bit of frustration, confusion, and a plugin that not only doesn’t do what you want but doesn’t do anything.

Solution? Develop your own plugin

The benefits of this course are:

Extreme familiarization with the code base ( You wrote it! )
Makes for identifying the area where bugs are coming from a fair bit easier
You don’t have to worry about licencing, you wrote it, it’s yours.

The above being said, I suppose it’s about time to get on to exactly how one goes about developing their own plugin and it’s assuming familiarization with their core and some basic JavaScript it can be done rather easily. For the purpose of this blog post we’ll be doing a plugin that transforms every YouTube link into a nice embedded video.

First, we start off with a basic structure which is necessary to eliminate the possibility of Namespace conflicts ( libraries aside from jQuery make use of the dollar sign $ )

(function($){

})(jQuery)

Now we must define our function, with jQuery however we’ll be making use of closures or anonymous functions and than assign it to a variable. This is how:

(function($){
    $.fn.youtubualize = function(){

    }
})(jQuery)

Now we get to the fun bits! jQuery feeds us a copy of itself ( available though the this supervariable ) ready to be manipulated, seeing as we’ll most likely have more than 1 link we’ll make use of jQuery’s each utility to cycle through all the links.

(function($){
     $.fn.youtubualize = function(){

        this.each(function(){

        });
    }
})(jQuery)

Now we must be away that within the callback we’re providing to the each utility this is only a string representing the YouTube link so we need to use jQuery’s CSS selectors to single out the element and modify it accordingly, this will be the most verbose part

(function($){
     $.fn.youtubualize = function(){

        this.each(function(){
            var url    = String(this);
            var flvURL = url.replace('watch?v=','v/');
            $('a[href="'+ url +'"]')
                .before('\
 \
 \
 \
 \
 \
 ')
                .remove();
        });
    }
})(jQuery)

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jQuery Development: Your own Plugins Part II

jQuery development: Your own plugins