Including critical path CSS extraction in my build - html

After reading up on critical path css, I was wondering how I could embed this into my builds. Are there any finished tools out there that does this already? The process needs to be automatable to avoid the inline CSS getting out of sync with other CSS.
If there is no such tool today, I can see how I could make one (say a grunt plugin), using this experimental script together with PhantomJS, but there is no point in re-inventing the wheel (if there is one already).

I had exactly the same idea - if you're still looking, I built exactly what we both wanted:
Critical Path CSS Generator. (I didn't end up using the tool you linked too since it misses psuedo selectors, media queries, non -webkit prefixed css rules etc).
More documentation is on the way, but basically just install PhantomJS first and then call the script like this:
phantomjs penthouse.js http://youSite.com/page1 yourSite.css > yourSite-criticalcss-page1.css
phantomjs penthouse.js http://youSite.com/page2 yourSite.css > yourSite-criticalcss-page2.css
You can pass in minified CSS as well as unminified - I don't modify the CSS except for removing unmatched selectors, rules (and I remove comments).

Use IISpeed or the Apache/Nginx PageSpeed modules
Google maintains some wonderful modules called PageSpeed that works for Apache and Nginx front servers. For those on .NET, just use IISpeed, the IIS equivalent of the PageSpeed modules. It is commercial and costs 100$, but is quite marvelous from a front-end perspective in what it does, and (among lots of other stuff) handles the main problem when using Penthouse: dealing with changing/dynamic content generation.
It works by injecting some javascript into the head of some of the first visitors to any page, analysing which css rules are actually being used. Then, after some rounds, it then collects these css rules and injects them as inline css in the head of that page for all subsequent visitors.
This is totally automatic and works on any ASP.NET page. You then avoid having to manually run Penthouse (mentioned above) on every page you like to speed up, and remembering to keep that css up to date (otherwise it will be out of date at some time, messing up your styles).
Penthouse is still great for pages where the content is mostly static.

Related

How to create file of USED css from a given webpage

With as all being very careful about resources within web development I am looking for a tool that you can pass a url and it show what CSS is actually used on that page but more importantly have the ability to download or extract that CSS Selectors and the actual css to create a single css of only the css needed to render that page, I have tried DustMe and various plugins. I realized I am not using 89% of bootstrap for example but picking it apart is almost impossible on pre built sites.
thanks
There is a online tool which provides that service, its not free though, unused-css.com
I'd recommend using uncss (requires node).
It can be added to your grunt build scripts to remove the css your are not using and is easy to configure
uncss.io works pretty well. Just enter your page URL and it will give you the cleaned CSS. It works for me on some pages, but not other pages.
REF: unused-css - (Paid Service)
or CSS Trashman
EDIT:
Use uncss git which requires node.js. It can be added to your built-in scripts to remove the unused css.

Is it more performant to have un-minified style in the HEAD or minified style in an external file?

I like the idea of encapsulating my CSS into separate files. This also brings the added advantage of being able to easily minify the CSS. But I know performance is negatively impacted by the overhead needed to pull these separate files from the server.
To address the latter point, people often suggest inlining the style or at least putting the CSS in the HEAD of the html document. I'm not going to inline because then editing the style becomes a nightmare. I can consider putting it in the head to increase performance, but I do not want to put it in there minified. I won't be able to read it, and it will be a pain to have to adjust the CSS once minified.
So my question is, What is the better option -- in terms of performance -- between these two?
Minified external CSS file
CSS placed in the HEAD but not minified
You are not considering browser-side caching in your evaluation. It is almost ALWAYS better to serve up CSS in an external file for cases where you will be using the same CSS file throughout a multi-page website. The reason for this is that once the CSS is downloaded on first page visit, assuming you have expiry headers set properly, the browser will not need to download the CSS on subsequent page loads until the expiry TTL is passed. This even holds true across multiple user sessions on a website, such that if a user visits the sites some days/weeks later, they may not need to download the CSS at all. If you served up in-page CSS, it would need to be downloaded on every page load.
Also minifying is typically not that big of a performance boost, as most server to browser connections will perform text compression on transmitted content anyway.
Of course it is also usually much easier to maintain CSS in an external file as you have pointed out.
The best option would be to:
Minify them all and bundle them in the server side with something like bundles for Asp.Net or brewer for nodejs, that way you remove the overhead you mentioned above.
To expand on my comment:
Generally, when optimising web page loading, you want to minimise the number of HTTP requests that the browser makes as these are expensive, time-wise; even requests for small files require the browser to send its request to a server, wait for the response, and then act accordingly. From that perspective, the best thing would be to put all the code for your page into a single file. However, this would be a page maintenance nightmare, and it also fails to take into account caching of resources by browsers, as covered by #MikeBrant.
A single css file (potentially composed of several concatenated minified files) is a good compromise between separation of style (css) and content (html), and performance. The same applies to javascript. You can also consider using a content delivery network (CDN) for Javascript if you're using a common library like JQuery as the user's browser may already have the library cached from visiting another site. Google's CDN serves a number of useful libraries.
Generally, you'll get far bigger performance gains from optimising images, enabling server compression, and removing extraneous javascript than you will from minification or inlining CSS. Images are almost always the "heaviest" elements of a page, and it is often very easy to reduce image size by 20-50% and maintain decent quality.

HTML Include: Separate Header and Footer

Can we include an HTML file / snippet from another HTML file?
My use case is related to how a website is built; in a simple form, a site typically has the same header and footer across the board. It is pretty straightforward if the site is equipped with e.g. PHP so you can do something like the include statement; we can contain the header and footer in separate files and include them later. But, what if the site is purely static i.e. no "back-end" support?
One thing that I had done in the past is to utilize templates in Dreamweaver. This worked but I'd prefer something that is more product-independent.
Thanks.
What you're looking for is Server Side Includes. It used to be available on most hostings, no idea what the situation is today.
Actually, a simple system based on a makefile and, why not, php's command line version, might also be helpful: a simple makefile that visits all php files in a directory, feeds it to php (eg, processes page decoration and stuff) and redirects the output to a corresponding html file should be enough to generate a set of uploadable, 100% static html files.
SSI is a great option if it is available to you as already suggested, I have always used PHP personally but as PHP is not available and if SSI isn't available then there is a JavaScript option as well.
The great thing with the JS option is the server doesn't need to have support for it due to the include scripts being client side. The bad thing is if the client doesn't have JS enabled in the browser the includes won't work. In saying that the vast majority of website users have JS enabled and this is displayed by most websites in the world who employ JS in 1 way or another.
Examples, the first one I found with a 2 second Google uses jQuery, have a look at the info here
There are also some AJAX plugins that could potentially be used for this at the jQuery website if it is a path you're interested in going down.
I hope this helps you :-)

Is there a way to get a list of all the CSS applied to a HTML fragment or page?

I know it's easy to get the CSS that is applied to a single node in HTML, using tools like the Firebug extension for Firefox, etc.
But is there a way to see all the CSS that is in effect on an entire page, or a larger fragment of HTML?
Specifically, we are cleaning up our one extremely large CSS file into smaller modules and would like to find out what CSS is used on a certain page, so we can move all the non-used CSS to another module.
Thank you all! These are the various solutions I've looked at now from your recommendations (collected here for people with the same problem):
Dust-Me Selectors (Firefox Add-on)
This does exactly what I need. Lists used and unused CSS selectors (for the current page, or the entire site, after spidering), and can dump both lists as CSV text. Great.
https://addons.mozilla.org/firefox/addon/5392/
CSS Usage (Firefox Add-on)
https://addons.mozilla.org/firefox/addon/10704/
WARI - Web Application Resource Inspector (Java tool)
Appears to only handle static code, not dynamically generated HTML as is present in most web applications that use ajax – which, unfortunately, makes it useless, at least for me
http://wari.konem.net/
CSS Redundancy Checker (Ruby script, requires Rubygems and Hpricot)
http://code.google.com/p/css-redundancy-checker/
TopStyle (Windows-only application, $79.95 (!!))
http://svanas.dynip.com/topstyle/
These are all cross-platform and free, except for TopStyle.
As far as tools go, you could use the css usage plugin for firebug. It will analyze pages for used css.
Or were you looking for a way to do it more programmaticly?
You can try Dust-Me Selectors, it's add-on for firefox, if you use firebug, as you stated, you may find useful CSS Usage.

Get Source of HTML File with CSS Inline

Is there a simple way to save an HTML page that has an external stylesheet (1 or more) referenced but force all of the rules to be inserted into the page itself, inline? So basically I want to move all external rules onto the elements that they affect themselves.
For what it's worth, I'm using nearly every major browser (incase the solution is browser-specific), and I'm on Windows (incase it's OS-specific).
I'm assuming you've seen the online tools that are available like this one? This online tool (which I have not tested but looks like it works) gives you the option of providing a url or source code and shows warnings for cross-browser compatibilities with your styles.
I use a tool that does something like that, but it was written for Ruby and TextMate for Mac. It is released by Campaign Monitor as a way of preparing HTML emails. It brings all the rules from the stylesheet and makes them inline styles.
It might give you a good start. I'll keep looking.
TextMate Email Bundle
The piece that does the heavy lifting is the TamTam RubyGem which brings the CSS inline. However, it seems to only support one style element (not link elements). If you could work with those restrictions, you could get it to work on Windows using Ruby and a ruby script file. Not quite drag and drop I'm afraid.
i use chrome extension Save Page WE