How can I do a conditional load of some CSS Files? - meteor

I have an app which needs to work in several languages, and several different color schemes and I would rather not load all the CSS every time since a large amount of it is not necessary or relavant (rtl css for example) but meteor automaticaly loads all CSS files he can find.
is there a way to selectively load CSS files?
Thanks.

If you place a CSS file within the reach of Meteor compiler, it's merged into the main app and in the current release there's nothing you can do about this.
You can however put the file in /public directory. Meteor won't touch it there, and you will be able to load it at will by adding <link/> tag to your page head.

Please have a look at https://stackoverflow.com/a/26694517/1523072 which seems a quite elegant way to do this and also explains why you shouldn't do it.
One of my apps currently loads 2.6MB compressed Javascript and 300KB compressed CSS, which seems like a lot. However, after the first visit all the resources are cached by my browser, which means the only thing that is transferred between browser and server after that is pure data.

Related

Is it good if I split my CSS file into multiple files for each page?

I'm Building a website, and It has a lot of pages approximately like 30 pages, and I linked these pages with one CSS file (the main css files) not to mention the other files such as bootstrap.min.css and other plugins that requires their own css files.
My point is that in all of these I'm using like the same css files, but in some pages I don't need all of the properties and styles in main.css file, so I'm thinking that I split that css file into multiple files, and create file called (global.css) and type in the properties that I'll need in all pages, and make another css file for each individual page.
My question is:-
Is it going to be helpful for the website speed if I split that main css into multiple css files and include only the necessary things for each page?
Ideally you want to abstracts your CSS files into many different SCSS files and then compiles them into one minified master file. One file for the header styling, one for links, one for typography. I was afraid of SCSS but now love it... Nothing changes in production, you are still running off CSS bit in development you are just making your life that little bit more organised.
NO,
you better dont want to do that if your code is small like less that 50kb or even 100kb
also if you provide seperate css for each page browser has to download each css file when user visit that page that will cost you one additional request for every single page this will slow down your page and affect your performace
instead I would suggest when your code goes live compress your code or minified it so youll get the more smaller version of your code
I also suggest to leverage browser caching (using .htaccess if you are using linux server)
above are the things which comes under front end performance improvement

Does CSS file sorting matter and if, why?

I have a website which uses 1 css file, it is called body.css and it consists of 841 lines. Should it be sorted in different files (header.css, footer.css page1.css, etc...), is it better in just 1 file or does it not matter?
The only thing I know for sure is sorting it in more files is a lot more readable.
Also if someone answers this I'd be most grateful for a little explanation.
My opinion would be one of two things.
1) If you know that your CSS will NEVER change once you've built it, I'd build multiple CSS files in the development stage (for readability), and then manually combine them before going live (to reduce http requests)
2) If you know that you're going to change your CSS once in a while, and need to keep it readable, I would build separate files and use code (providing you're using some sort of programming language) to combine them at runtime build time (runtime minification/combination is a resource pig).
With either option I would highly recommend caching on the client side in order to further reduce http requests.
So, there are good reasons in both cases...
A solution that would allow you to get the best of both ideas would be :
To develop using several small CSS files
i.e. easier to develop
To have a build process for your application, that "combines" those files into one
That build process could also minify that big file, btw
It obviously means that your application must have some
configuration stuff that allows it to swith from "multi-files mode" to "mono-file mode".
And to use, in production, only the big file i.e. Single CSS
Result : faster loading pages
maybe this will help you..
For optimal performance it is better to have only one css file.
But for readability it would be better to have different files for different parts.
Take a look at tools like SASS, which help do that without sacrifice performance. Additionally it has features to make your files even more readable by introducing variables, function and much more.
Using more files means more requests. It will take more time to load and make unnecessary requests to the server. I'd stay with one file.
The only good reason to have other css files would be if you have third-party components, to keep them separated and be able to update them easily.
The order matters: Rules loaded later will override rules with the same name loaded before (this is valid even for rules in the same file).
What do you mean that your website uses one CSS file? Normally you'd write your style definitions in multiple files, and they are concatenated (or not) into one file. My point is, what you are working on in your development environment should stay modular, readable, it shouldn't be influenced by what you have in production.
As for the order of the CSS files, yes, it matters, as you can overwrite your previous definitions.
For optimal caching I'd recommend you to build all the vendor CSS in one file, and your CSS in another file, versioned, so that if you change something in your code, only that file has to be updated by the browser.
But these things depend on the infrastructure. As the browsers are able now to send multiple requests simultaneously, having multiple files can lead to faster page load than only one. But I'm not sure about this.
you might want to take a look at gulp to automatically optimize, and minify your CSS code.
All css in one file is OK.
But it's free : you can make as many css file as you want.
However usually this is how it is:
1 global css file for the entire page. You put the common css in here that is useful for every page on your site. You can call it app.css or style.css or mywebsite.css or any name you want.
1 specific css file for a specific page when you want to specially separate this css from the global css file. Because it will contains css only useful for a few pages. For example you have a special component made by your own or a special functionnality. Example : you have made a spcial javascript code working with some html for uploading some file and you want to have your code js/css separate.
Usually, you can also have one css page for each page, but always one global css file for the entire site.
Note : Same question is also valid for javascript
Note 2 : You can also think about using a framework to minify your javascript and css into one single css / js file at the end. At work our technical boss use wro4j which works for java but it should exists many more other frameworks as you can search on google.

SASS : making underscore file names actually create css files

By default SASS looks at the filename and determines whether to make a css file out of it. I'm wondering if there is a way to prevent this from happening.
We're building a large website and lots of front-end developers are editing the css, but we only have one dev server. Sure some things you can see happen locally, but often you can only see the real rendered way on the server.
So, when I push my compiled css file to the server, my co-workers' css gets clobbered until s/he commits and I do an svn:update, etc, etc.
However, if we were working in different SASS file, and those css files were getting created, I would only have to push up, say, the forms.css file instead of the whole thing.
Then for Production, we'd put it back to the way SASS normally works.
The only other way I can figure to do this is to do a mass rename of files, which seem very messy.
Thanks in advance.
The entire point of partials is that they don't get compiled into files. If you want a sass file to be turned into a css file, remove the underscore.
Your real problem seems the be that you're putting compiled CSS in your version control. Don't do that. Only commit Sass, and compile it into CSS server-side with a post-receive hook or something.

Django template, 'include' css rather than using link

Recently we have experienced the problem of browsers caching the css files, so that when we move code to another web server we get unexpected and unwanted results.
Having read various solutions it occurred to me that the css file could be included in the template. Rather than write
<link href="/static/css/parentx.css" rel="stylesheet" type="text/css">
we could put
<style>{% include "static/css/parent.css" %}</style>
which would embed the css in the html. It has the added benefit of reducing the number of calls back to the server for the css file but the disadvantage of not caching the css at all and not allowing the web server to provide the static files. However, these files are quite small, typically about 12K.
I propose this as a temporary measure as I have just discovered the existence of asset management plugins that look to do a better job.
I have never seen the use of the 'include' template command to get css (and javascript) files so perhaps there is a drawback of which I am unaware?
Not caching the CSS file at all will slow page loading though it's unnecessary.
Cache your CSS as long as possible and necessary and when you need to invalidate cache, a sure way is to load another file, I mean the same file with another name. It could be parent1391234565.css or parent-v003.css or parent130307.css or parent-4e6ca1437f2d.css. If you told browsers to download parent-v002.css, you're pretty certain they don't have parent-v003.css in their cache!

Best practice for working with less, or minified CSS

I'm considering using less in an upcoming project but have been trying to figure out the best way to work with it while in development.
Usually when developing a site I'll write my html and css then start testing it in the browser, see how it looks, refine, reload, and repeat the whole process until I'm happy with how everything looks.
A crucial part of the process is using the Inspect Element feature in the browser to identify the piece of CSS I need to change. Usually just by looking at the line number I know exactly where to go in my CSS file.
But if I use Less (or any other method of combining/compressing my CSS) it makes the line numbers useless. I know I could use Find to search for the section of code but line numbers are much faster.
This is especially true when working on a project that involves other developers or large CSS files.
I just wondered how others deal with this, or maybe there's a better process?
Minified CSS really should only be going out to the production version of your site. When you're performing tests/changes etc, this should all be done in some test or development version of your site in a secondary server area where you can have the line-numbers version of css available. The same would go for JavaScript. On the production viewable copy, you want it minified. In development, you don't.
In any event, you should always have 2 copies of your css. The first copy is the primary source copy that is your development copy. It has all of your properly formatted styles with line-breaks in it. The other is the very latest minified version of your css that went to production. This will allow you to switch between the 2 files rapidly in the event that you need to work something out, assuming your site uses some sort of templated delivery (layout pages, master pages, or whatever).
The minified version will only be useful in the final delivery. All other needs should use the master copy. It might not be a bad idea to put a configuration in server-side portion of your site that determines what style sheet to use. That way you can simply change a configuration setting and go into a "debug" mode.
I agree with Joel - that's how I handle it. A build script minifies the CSS (and JS) before each release is FTP'ed to production. I just have a switch in PHP like:
if ($config->prod()) {
// incldue the minfied css
} else {
// include all the original files
}
Personnaly, I use an ant build script to make a production version:
it "condense" multiple css files in one
then it minify them with YUI compressor
same for scripts
(page recomposition to point to the newly generated files)
this way you divide your http request for those files, and gain some bandwith from 30% to 70% i'd say. depends on gzip also.
in my case, the dev version have:
18 css weighting 178ko
reduced down to 1 css at 96ko in the production version
I personally use tools to minify and inject the CSS into the browser each time i save my Less file. So i see each change immediately. This way it's pretty clear what just happened. I don't need the referencing line numbers that much any more.
I recently started using source maps, to see the correct file and line numbers (of my less files) when inspecting CSS in the browser again. I think that is what you are looking for. I personally don't need this extra fanciness that much.

Resources