Minifying JS/CSS files - javascript

I have a template that has over 20 js/css files that it references to and of course this makes for a lot of http requests. I thought about stitching them together with php using minijs.php/mini.php but the problem Im seeing is the page seems to load slower when using minijs.php/mini.php. I used YSlow and just having each one linked individually it shows 3 seconds to load, when I use the minified solution it takes 7-10 seconds to load, even when cached. Does anyone recommend a better solution or do you even recommend combining them all together dynamically like this?

Yes, I do recommend combining the files and minifying them, ideally using either YUI Compressor, Google Closure Compiler, or, what jQuery recently switched to, UglifyJS.
As for a bit of how and why, read this and search Google for "why should I combine web site assets?".
Also bear in mind that this should be a preprocessing step, or at the very least something that is rendered once and cached and thereafter served by a static file server (Apache or Nginx, php should not be involved).

Check this python script.
http://github.com/hkasera/minify
It minifies js as well as css files too. It stores detailed log files and you can add this script as a git hook and save yourself from doing it manually everytime. I have created it during a project and it helped me a lot.
Hope it may help!

you can use many online tools which have features for compressing and combining multiple files.
for javascript compression you can use jsCompressor
and for css you can use CSS compressor CSSCompressor

Related

combining javascript files

I've launched a redesign of our website and I'm using quite a bit of Javascript for the first time.
I've learned that I should be combining all my javascript and css into one file (each obviously) but while I know I can combine the css without problems but the javascript I'm not sure of.
I have to load:
jquery.min.js <-- I load the top two from ajax.googleapis.com, is that a good idea
jquery-ui.min.js
javascript for Facebook
some for google plus button
same for twitter
some for google analytics
then some inline stuff to hide divs which javascript users shouldn't see and that type of thing.
you can see it here: traditionalirishgifts.com
So can I just copy and paste the contents of all these files into one big file. Find some way to minify (haven't looked into that fully yet) it. Load this one file right at the bottom of my page before and bingo?
I'd use this tool: http://jscompress.com/
JSCompress.com is an online javascript compressor that allows you to
compress and minify your javascript files. Compressed javascript files
are ideal for production environments since they typically reduce the
size of the file by 30-90%. Most of the filesize reduction is achieved
by removing comments and extra whitespace characters that are not
needed by web browsers or visitors.
You should always be able to merge all your external JavaScripts into one file. You can use a server-side compressor to cache it and serve it as one file. It does put some constraints on the files, like which file should load first etc. Also, if there is a syntax error anywhere it will crash completely.
Keep in mind that 3rd party code like code from google can't be mixed in. Usually there is some kind of authentication going on (or an API key in the URL). If you try to cache that code, it will stop working after a while. So you do need to keep those separate.

compressing .js and .css files on push of the website

I am not even sure if something like I want is possible, so I am asking you guys to just let me know if anyone did that before. So, my goal is to when I click on "Publish" website in VS2010, to have all javascript files compressed into one, same with css and then in my layout file change the references from all different js and css files to only those two merged ones. Is that doable? Or maybe it's doable but in more manual way?
Of course the goal here is to have only two calls to external files on the website, but when I develop I need to see all files so that I can actually work with it. I guess I could do it manually before each push, but I'd rather have it done automatically using some script or something. I didn't try anything yet, and I am not looking for ready solution, I am just looking to get to know the problem better and maybe some tips.
Thanks a lot!
This is built into ASP.net 4.5. But in the mean time, you should look at the following projects
YUI Compressor
The objective of this project is to compress any Javascript and Cascading Style Sheets to an efficient level that works exactly as the original source, before it was minified.
Cassette
Cassette automatically sorts, concatenates, minifies, caches and versions all your JavaScript, CoffeeScript, CSS, LESS and HTML templates.
RequestReduce
Super Simple Auto Spriting, Minification and Bundling solution
No need to tell RequestReduce where your resources are
Your CSS and Javascript can be anywhere - even on an external host
RequestReduce finds them at runtime automatically
SquishIt
SquishIt lets you squish some JavaScript and CSS. And also some LESS and CoffeeScript.
Combres
.NET library which enables minification, compression, combination, and caching of JavaScript and CSS resources for ASP.NET and ASP.NET MVC web applications. Simply put, it helps your applications rank better with YSlow and PageSpeed.
Chirpy
Mashes, minifies, and validates your javascript, stylesheet, and dotless files. Chirpy can also auto-update T4MVC and other T4 templates.
Scott Hanselman wrote a good overview blog post about this topic a while back.
I voted up the answer that mentioned Cassette but I'll detail that particular choice a little more. Cassette is pretty configurable, but under the most common option, it allows you to reference CSS and Javascript resources through syntax like this:
Bundles.Reference("Scripts/aFolderOfScriptsThatNeedsToLoadFirst", "first");
Bundles.Reference("Scripts/aFolderOfScripts");
Bundles.Reference("Styles/aFolderOfStyles");
You would then render these in your master or layout pages like this:
#Bundles.RenderStylesheets()
#Bundles.RenderScripts("first")
#Bundles.RenderScripts()
During development, your scripts and styles will be included as individual files, and Cassette will try to help you out by detecting changes and trying to make the browser reload those files. This approach is great for debugging into libraries like knockout when they're doing something you don't expect. And, the best part, when you launch the site, you just change the web.config and Cassette will minify and bundle all your files into as few bundles as possible.
You can find more detail in their documentation (which is pretty good though sometimes lags behind development): http://getcassette.net/documentation/getting-started
Have a look at YUI compressor # codeplex.com this could be really helpful.
What I have done before is setup a post-build event, have it run a simple batch file which minimizes your source files. Then if you're in release mode (not in debug mode), you would reference the minimized source files. http://www.west-wind.com/weblog/posts/2007/Jan/19/Detecting-ASPNET-Debug-mode
I haven't heard about publish minification. I think use should choose between dynamical minification like SquishIt or compile time like YuiCompressor or AjaxMinifier.
I prefer compile time. I don't think it's very critical to have to compile time changing files. If you have huge css/js code lines you can choose this action only for release compilation and if it helps publish this files only in needed build cinfigurations.
I don't know if there is any possible way to somehow hook into the functionality from that 'Publish' button/whatever it is, but it's surely possible to have that kind of 'static build process'.
Personally I'm using Apache ANT to script exactly what you've described there. So you're developing on your uncompressed js/html/css files and when you're done, you call like ant build which then minifies, compresses, stripes and publishes your whole web application.
Example script: https://github.com/jAndreas/typeof-NaN-2.0/blob/master/build/build.xml

Combining and Compressing multiple JavaScript files into a single file in a Django project

What is the simplest way to combine JavaScript files into a single file in a Django project?
Explanation
I want this to work with Ember.js/Backbone where you (usually) have many different JavaScript in multiple directories. Directories would all be in one folder called app/ for example, like: app/views/ app/models/ /app/routers/
Requirements
Work together with the staticfiles app
Still be separated while in development mode for easier debugging (only compile when calling collectstatic?)
Work with Require.js (guess that shouldn't be too hard, but putting it in here to be sure)
Extra credit
Explain a best practices way of combining Django and Ember/Backbone.
I am an happy user of django compressor, it does combine, minify, debug-friendly, you can use it with staticfiles, easy to plug with custom storage backend (eg. S3)
https://github.com/jezdez/django_compressor
The reason you want to combine many files into one is so to minimize latency of setting up and tearing down http requests, the fewer you make the better. However, many newer browsers are downloading JavaScript files in parallel (still executing sequentially). The consequence is that downloading a single 1Mb file may be slower than three 350Kb files.
you can use from CDNs.
As mentioned in the previous answer, django-compressor is nice, but you often get better loading times when using a dedicated javascript loader instead. My tip is to check out Head.js for example (http://headjs.com/) (there are tons other out there as well). Often combining scripts can be contra productive when considering caching, using javascript located on CDN:s etc.
One thing to remember is that Iphone 3/4 will just cache 15/25KB of javascript, so if you have huge scripts and combine them you can run into trouble. http://www.phpied.com/iphone-caching/

How to update HTML script and link references when combining JavaScript and CSS files?

Multiple sites reference combining JavaScript and CSS files to improve web page performance, including examples of using ANT build scripts to concatenate the files prior to deployment.
I've search, and haven't found any information how to automate updating references to those files in HTML and other documents. I am looking to avoid hacking together something error prone, and want to learn from others who have automated builds in the past.
Are there automated tools in the wild to complete this task that I'm not seeing? Are there recommended processes to update the script and link tags in HTML? Can these solutions be integrated with ANT or similar build tools?
There sure is and it's a smart thing to do.
I found a PHP solution, don't know it that's okay for you, but if it isn't you can still read it's source (it's not difficult) and learn a lot. The solution works like this:
Rewrite your requests like this: from css/main.css and css/skin.css to css/main.css,skin.css (of course you can put many more).
Use apache's mod_rewrite to redirect this request to a script (in our case combine.php), that will combine all files to a single one.
The script combines all the files and sends the combined file. Then it saves it to a cache folder.
Next time around it checks if there is an up-to-date version of the cache and serves that one. If the latest file modification time has changed, it discards the cache.
The solution works great and it even makes use of HTTP cache headers and spits out an [ETags], which you should do anyway.
You are correct this is a great way to speed up page loading. It will even work in conjunction with a CDN, which the other poster recommended.
Here is a small script that will pack multiple files in to one for deployment. It supports both JS and CSS, and will even "minify" them by removing whitespace, etc. Just hook this in to your build and deploy scripts.
juicer: http://cjohansen.no/en/ruby/juicer_a_css_and_javascript_packaging_tool
What even better, it will follow JS and CSS import statements, so you only need to point your HTML files to the loader file and it will work in both development and production. (Assuming you replace the loader file with the combined file on deployment.)
There are others, including some run-time solutions. But it sounds like you have a build process in place anyway.
As far as HTML updating, if you still need it, since automated deployments are very popular in the Ruby world, and you may find some standalone utilities to help even for non-ruby projects. (As above) Methinks this would be best handled by your own project's template language, though. (With a static resource revision id, or such.)
Good luck, and let us know what you find.
I think what you really want is a CDN Content Delivery Network.
Read about it here
http://developer.yahoo.com/performance/rules.html
http://en.wikipedia.org/wiki/Content_delivery_network

YUICompressor or similar in PHP?

I've been using yuicompressor.jar on my test server for on-the-fly minimisation of changed JavaScript files. Now that I have deployed the website to the public server, I noticed that the server's policies forbid the use of exec() or its equivalents, so no more java execution for me.
Is there a decent on-the-fly JS compressor implemented in PHP? The only thing resembling this that I was able to find was Minify, but it's more of a full-blown compression solution with cache and everything. I want to keep the files separate and have the minimised files follow my own naming conventions, so Minify is a bit too complex for this purpose.
The tool, like yuicompressor, should be able to take either a filename or JavaScript as input and should either write to a file or output the compressed JavaScript.
EDIT: To clarify, I'm looking for something that does not have to be used as a standalone (i.e. it can be called from a function, rather than sniffing my GET variables). If I just wanted a compressor, Minify would obviously be a good choice.
EDIT2: A lot has changed in the five years since I asked this question. Today I would strongly recommend separating the front-end workflow from the server code. There are plenty of good tools for JS development around and except for the most trivial jQuery enhancements it's a better idea to have a full workflow with automated bundling, testing and linting in place and just deploy the minified bundles rather than the raw files.
Yes there is, it's called minify.
The only thing in to worry about in the way of complexity is setting up a group, and there's really nothing to it. Edit the groupsConfig.php file if you want multiple JS/CSS in one <script> or <link> statement:
return array(
'js-common' => array('//js/jquery/jquery-1.3.2.min.js', '//js/common.js', '//js/visuals.js',
'//js/jquery/facebox.js'),
'css-common' => array('//css/main.css', '//css/layout.css','//css/facebox.css')
);
To include the above 'js-common' group, do this:
<script type="text/javascript" src="/min/g=js-common"></script>
(i know i was looking for the exact same thing not knowing how to deal directly with the jar file using php - that's how i ended up here so i'm sharing what i found)
Minify is a huge library with tons of functionalities. However the minifying part is a very tiny class : http://code.google.com/p/minify/source/browse/trunk/min/lib/Minify/YUICompressor.php
& very very easy to use :
//set the path to the jar file
Minify_YUIcompressor::$jarFile=_ROOT.'libs/java/yuicompressor.jar';
//set the path to a writable temp folder
Minify_YUIcompressor::$tempDir=_ROOT.'temp/';
//minify
$yourcssminified=Minify_YUIcompressor::minifyCss($yourcssstringnotminified,$youroptions)
same process for js, if you need more functionalities just pick from the library & read the source to see how you can make direct call from your app.
I didn't read the question well, since minify is based on using the jar files, the op can't use it anyway with his server config
Minify also include other minifying methods than yui, for example:
http://code.google.com/p/minify/source/browse/trunk/min/lib/JSMinPlus.php?r=443&spec=svn468
Try Lissa:
Lissa is a generic CSS and JavaScript loading utility. Lissa is an extension of the YUI PHP Loader aimed at solving one of the current loader limitations; combo loading. YUI PHP Loader ships with a combo loader that is capable of reducing HTTP requests and increasing performance by outputting all the YUI JavaScript and/or CSS requirements as a single request per resource type. Meaning even if you needed 8 YUI components which ultimately boil down to say 13 files you would still only make 2 HTTP requests; one for the CSS and another for the JavaScript. That's great, but what about custom non-YUI resources. YUI PHP Loader will load them, but it loads them as separate includes and thus they miss out on benefits of the combo service and the number of HTTP requests for the page increases. Lissa works around this limitation by using the YUI PHP Loader to handle the loading and sort of YUI and/or custom resource dependencies and pairs that functional with Minify.

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