Rickard Nilsson

In a previous post I described the importance of optimizing your web site resources and how you can do it using the open source tool Ajax Minifier. I’ve received a few questions about how to automate this process and now I want to share a ASP.NET MVC 3 template with the combining and minification built in as a post compile step.

Since my last post Ajax Minifier is now available as a NuGet package and is easily installed in your solution either via NuGet Package Manager or using the NuGet Package Manager Console command:

PM> Install-Package AjaxMin

However, to get the AjaxMin.exe you’ll have to download it manually from Codeplex. My MVC 3 template is build on a simple Internet Application MVC 3 template with Razor and HTML5 semantic markup. My additions to automate resource optimizations consists of the following:

After the web project is built a custom target is called:

<Import Project="$(MSBuildProjectDirectory)\AfterBuild.tasks" />

<Target Name="AfterBuild">

    <CallTarget Targets="Minify">CallTarget>

Target>

The after build target executes the AjaxMin executable:

<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

    <PropertyGroup>

        <BuildLibPath>$(MSBuildProjectDirectory)\..\packagesBuildLibPath>

        <Ajaxmin>$(BuildLibPath)\AjaxMin.4.62.4618.15628\bin\Ajaxmin.exeAjaxmin>

    PropertyGroup>

    <Target Name="Minify">

        <Exec Command='"$(Ajaxmin)" -js -xml minify.js.xml -clobber' Condition="'$(Configuration)' == 'Release'" />

        <Exec Command='"$(Ajaxmin) -css -xml minify.css.xml -clobber' Condition="'$(Configuration)' == 'Release'" />

    Target>

Project>

The xml files minify.js.xml and minify.css.xml are used to define which resources should be merged together, minified and where to output the result.

<root>

  <output path="Scripts/Mvc3Application.min.js">

    <input path="Scripts/myplugin.js"/>

    <input path="Scripts/viewModel.js"/>

    <input path="Scripts/foobar.js"/>

  output>

root>

Download ASP.NET MVC 3 Template

Target: .NET 4.0

It has been almost three years since I wrote my top ranking post on this blog: Applying stylesheets dynamically with jQuery. It was a quick and dirty example of a testing scenario pulled together for a colleague but it has become my number one linked post. It is still the post that gets the most hits every month because it is the first hit on Google for jquery add stylesheet which seems to be a lot of people has trouble with.

So, I felt it was time to do another post on the subject considering I’ve been using jQuery more or less every day these last three years.

jQuery Plugin

I’ve created a simple jQuery plugin for adding or switching out stylesheets dynamically and interactively and it can be used like this:

<ul>

    <li><a href="#" rel="1.css">Apply Stylesheet 1a>li>

    <li><a href="#" rel="2.css">Apply Stylesheet 2a>li>

    <li><a href="#" rel="3.css">Apply Stylesheet 3a>li>

ul>

$('a').click(function () {

    $.stylesheets.clear().add($(this).attr('rel'));

    return false;

});

$.stylesheets = (function () {

    var stylesheets,

        add,

        clear;

    add = function (cssfile) {

        $('head').append(''" rel="stylesheet" />');

        return stylesheets;

    };

    clear = function () {

        $('head link[rel=stylesheet]').remove();

        return stylesheets;

    };

    return stylesheets = {

        add: add,

        clear: clear

    };

} ());

Download source / demo

Why should you bother with combing and minifying JavaScript and CSS files? If you are a web developer working with sites with any significant traffic, you simply should because of the impact it will have on the load time of your site and how your visitors will perceive the page loading faster.

In the field of web site optimization, pioneered by Yahoo, there are many rules or guidelines which you should try to follow in hunt for milliseconds on the client side. In fact, it’s on the client that you will get the most value for your optimization work rather than on the server side [SOUDERS]. This is a subset of the rules regarding JavaScript and CSS.

Guidelines for web site optimization

• Put all your CSS in separate .css files
• Put your CSS links as early in the header section of the page as possible
• Minify your CSS files, i.e. remove whitespace etc.
• Try combining all of your CSS files into one
  
  
• Put all your JavaScript code in separate .js files
• Put your JavaScript imports as close to the tag as possible
• Minify your JavaScript files
• Try combing all of your JavaScript files into one
• If possible try loading large scripts asynchronously
  
  
• Enable GZIP compression on all your static content, e.g. CSS and JavaScript files
• Set far future expire headers on your static content

Microsoft Ajax Minifier

I have searched for a tool that could help me implement many of the optimization guidelines and found a few worth taking a closer look at, one of these is the Google Closure Compiler. It has loads of features including file combining, minification, “compiling” your JavaScript into better JavaScript, as well as an API for loading your scripts asynchronously.

However, being a pragmatic .NET developer, I chose the most easily accessible tool available for me, which is Microsoft’s Ajax Minifier. It’s a free tool available on Codeplex and documentation is provided on the www.asp.net site.

Ajax Minifier comes as a command-line application and after you have installed it you can use it through it’s own command prompt.

Minifying JavaScript

Minifying a single JavaScript file is pretty straight forward. Simply type in the command prompt:

• ajaxmin inputfile.js –out outputfile.js

then add –clobber if you wish to override the outputfile.js if it exists, as in:

• ajaxmin inputfile.js –out outputfile.js –clobber

Minifying CSS

Minifying a single CSS file is equally simplistic as follows:

• ajaxmin inputfile.css –out outputfile.css –clobber

As before, add –clobber to override any existing output file.

Combining files

Unfortunately there are no documentation on the asp.net site about how to combine multiple files into one, however, the ajaxmin command itself provides a hint given the /? parameter:

As an alternative to the input file parameter you can use the –xml parameter and supplying it with the path to an xml file of the following format:

xml version="1.0" encoding="utf-8"?> 

<root> 

    <output path="outputfile.js"> 

        <input path="inputfile1.js"/> 

        <input path="inputfile2.js"/> 

        -… -> 

    output> 

root> 

The Ajax Minifier will combine all of your input files into one, minify it, and produce the result in the output file. Using this approach you can also control in what order the files are loaded into the page and sort out any dependency issues, just as you would, had you listed includes in the regular html file (or .master or whatever).

The Ajax Minifier does not seem to have the smarts to deduce that this is JavaScript files so you need to supply it with a –js parameter like so:

• ajaxmin –js –xml jsxmlfile.xml –clobber

I haven’t found a way to combine JavaScript and CSS in the same xml file so you need to make a separate file for you CSS files with the same format as above and instead of the –js parameter, use the –css dito:

• ajaxmin –css –xml cssxmlfile.xml –clobber

A colleague of mine asked me how to apply a stylesheet to a web page dynamically using jQuery and I had never done such a thing but my first thought was that is must be pretty simple. I've spent a lot of time thinking of so many things other than web et. al. so it was nice to delve into some of that stuff again. Check out the live demo

As we know stylesheets are defined in the head section of an html file like this

<html>

    <head>

        <link rel="stylesheet" href="stylesheet.css" type="text/css" />

    head>

    <body>

    ...

html>

Now, say that we want to apply another stylesheet dynamically after the fact, so to speak, triggered by some event. This could be a button click or some other arbitrary event that is triggered. So, what we want to do is simply insert a new element into the head section of the page DOM. This can be done in a couple of lines of jQuery:

$(document).ready(function () {

    $("a").click(function () {

        $('head').append('');

    });

});

The key is at what time we add the link to the style sheet. The first line in the code above repeated here asserts that the DOM is ready for manipulation.

$(document).ready(function () {

    //...

});

The second part repeated here adds a click event to all hyperlinks in the page.

$("a").click(function() { //...

And the very task is performed by the last piece of code where the head element is appended with a new link element.

$('head').append('');