The browser I'm using, qutebrowser, allows me to set a CSS file that applies those styles to every web site (but doesn't allow you to set it per page/domain, as far as I can tell), so I downloaded a dark theme CSS stylesheet from solarized-everything-css, but it seems the result on some website is unsatisfactory.
Therefore, I'd like to know if CSS offers a way to not apply a sequence of rulesets (in my case it'd be the whole stylesheet) on some domains. Something long the lines of
#this-web-site-is-NOT-in-the-black-list-in("list.txt") {
/* the content of the dark theme CSS goes here*/
}
If it was possible, then I would add each problematic site to that sort of blacklist.
CSS itself cannot do this, because CSS is designed to apply only to a site from which it is loaded within the browser environment. Normally this happens by looking at resources listed in an HTML file's <head>, but can also happen from JavaScript injection via userscripts/addons/extensions a user has installed in their web browser.
So you need to use a 'user' style for this, which means you need to use a web browser that supports this. If the browser you're using (qutebrowser) does not allow you to set specific domains/URLs, then this will not be possible for you without creating your own user script (written in JavaScript, presumably) to apply this functionality on top of what the browser supports natively.
I'm writing a Chrome extension that injects HTML into a displayed page. I want the injected HTML to have it's own style, protected from the CSS that may be present in the host page.
I've tried using conventional CSS, and still suffer from style corruption from the host page.
After watching the Polymer presentation from I/O 15, I was wondering if there are any new, Chrome-specific techniques that I can use to achieve this?
What you will want to look into is shadow-dom. This will enable you to create a widget/component (which would be your injected html). This would mean that the DOM tree for the widget/component is encapsulated and no external styles from the page will affect it. There is a good article on html5rocks covering this. You may also want to look into WebComponents. Bear in mind that this functionality is only available in the latest browser versions.
Two things that I currently use at my place of work are:
css-modules
react-css-modules
I use react at work, hence react-css-modules, but css-modules should work in your case. It's not Chrome specific, but we use them within the context of each component we build. Basically, like the docs state, a class of row would become something like table__row___2w27N. The breakdown of the built name is the filename of the CSS than the class name followed by a base64 hash of 5 char. I hope this helps.
One potential downside is Webpack would be required.
Here is an example of our component folder structure:
- component
- Component.jsx/js
- component.css/scss/sass
- component.test.js
I am building an app on top of webkit, I need to modify a CSS file (edit a selector), which I can do once the page is loaded using Javascript. In my particular scenario I may load the page many times and I would like to mutate the CSS in the cache (using Javascript, as opposed to hacking webkit). Any ideas?
Without entirely understanding your use case I see at least three cheap and fast methods to override some styles:
use one of the many bookmarklets out there (e.g. this one by Paul Irish) to play around injecting styles or
use a short snippet of javascript ondomready to inject a stylesheet with selectors and styles into the head of the document (similar to the bookmarklet above) or
define a specific enough CSS selector and simply include an inline style element in your document (which I would not suggest)
All three methods are basically the same. Depending on what you have, are able to edit or want to achieve either method may be more suitable.
User stylesheets or extensions like Stylebot for Google Chrome may be another possibility to look into.
Weird stuff like loading referenced stylesheets via javascript's XHR, get the content of the file, modify or inject stuff and reapply the styles to the current document are possible as well but probably not what you're looking for.
So to give you an idea of what it is I am trying to do, OOCSS Framework uses a ton of classes, I'm about to package up a mobile site that is about ~2.5 megs and would like to remove all unused classes from the files. Sure, I could do it by hand but it would be much easier if something like this existed for the future.
There is a Firefox extension called Dust Me Selectors
It extracts all the selectors from all the stylesheets on the page you’re viewing, then analyzes that page to see which of those selectors are not used. The data is then stored in your user preferences, so that as you continue to navigate around a site, selectors will be crossed off the list as they’re encountered.
You’ll end up with a profile of which selectors are not used anywhere on the site.
or give Unused Css a try
http://unused-css.com/
from Unused Css site:
Latish Sehgal has written a windows application to find and remove unused CSS classes. I haven't tested it but from the description, you have to provide the path of your html files and one CSS file. The program will then list the unused CSS selectors. From the screenshot, it looks like there is no way to export this list or download a new clean CSS file. It also looks like the service is limited to one CSS file. If you have multiple files you want to clean, you have to clean them one by one.
Dust-Me Selectors is a Firefox extension (for v1.5 or later) that finds unused CSS selectors. It extracts all the selectors from all the stylesheets on the page you're viewing, then analyzes that page to see which of those selectors are not used. The data is then stored so that when testing subsequent pages, selectors can be crossed off the list as they're encountered. This tool is supposed to be able to spider a whole website but I unfortunately could make it work. Also, I don't believe you can configure and download the CSS file with the styles removed.
Topstyle is a windows application including a bunch of tools to edit CSS. I haven't tested it much but it looks like it has the ability to removed unused CSS selectors. This software costs 80 USD.
Liquidcity CSS cleaner is a php script that uses regular expressions to check the styles of one page. It will tell you the classes that aren't available in the HTML code. I haven't tested this solution.
Deadweight is a CSS coverage tool. Given a set of stylesheets and a set of URLs, it determines which selectors are actually used and lists which can be "safely" deleted. This tool is a ruby module and will only work with rails website. The unused selectors have to be manually removed from the CSS file.
Helium CSS is a javascript tool for discovering unused CSS across many pages on a web site. You first have to install the javascript file to the page you want to test. Then, you have to call a helium function to start the cleaning.
UnusedCSS.com is web application with an easy to use interface. Type the url of a site and you will get a list of CSS selectors. For each selector, a number indicates how many times a selector is used. This service has a few limitations. The #import statement is not supported. You can't configure and download the new clean CSS file.
CSSESS is a bookmarklet that helps you find unused CSS selectors on any site. This tool is pretty easy to use but it won't let you configure and download clean CSS files. It will only list unused CSS files.
We can write CSS as the following types:
Inline CSS
Embedded CSS
External CSS
I would like to know pros and cons of each.
It's all about where in the pipeline you need the CSS as I see it.
1. inline css
Pros: Great for quick fixes/prototyping and simple tests without having to swap back and forth between the .css document and the actual HTML file.
Pros: Many email clients do NOT allow the use of external .css referencing because of possible spam/abuse. Embedding might help.
Cons: Fills up HTML space/takes bandwidth, not resuable accross pages - not even IFRAMES.
2. embedded css
Pros: Same as above regarding prototype, but easier to cut out of the final prototype and put into an external file when templates are done.
Cons: Some email clients do not allow styles in the [head] as the head-tags are removed by most webmail clients.
3. external css
Pros: Easy to maintain and reuse across websites with more than 1 page.
Pros: Cacheable = less bandwidth = faster page rendering after second page load
Pros: External files including .css can be hosted on CDN's and thereby making less requests the the firewall/webserver hosting the HTML pages (if on different hosts).
Pros: Compilable, you could automatically remove all of the unused space from the final build, just as jQuery has a developer version and a compressed version = faster download = faster user experience + less bandwidth use = faster internet! (we like!!!)
Cons: Normally removed from HTML mails = messy HTML layout.
Cons: Makes an extra HTTP request per file = more resources used in the Firewalls/routers.
I hope you could use some of this?
I'm going to submit the opinion that external style sheets are the only way to go.
inline CSS mixes content with presentation and leads to an awful mess.
embedded CSS gets loaded with every page request, changes cannot be shared across pages, and the content cannot be cached.
I have nothing against either method per se, but if planning a new site or application, you should plan for external style sheets.
Inline
Quick, but very dirty
This is (sadly) also the only really sane option for HTML formatted email as other forms often get discarded by various email clients.
Embedded
Doesn't require an extra HTTP request, but doesn't have the benefits of:
Linked
Can be cached, reused between pages, more easily tested with validators.
You want external css. It's the easiest to maintain, external css also simplifies caching. Embedded means that each separate html file will need to have it's own css, meaning bigger file size and lots of headaches when changing the css. Inline css is even harder to maintain.
External css is the way to go.
Where to start!!??
Say you had a site with 3 pages...
You could get away with Inline CSS (i.e. CSS on the page itself, within tags).
If you had a 100 page website...
You wouldn't want to change the CSS on each page individually (or would you?!)...
So including an external CSS sheet would be the nicer way to go.
Inline CSS is generally bad. It's much easier to modify the style of a page when all the styles are located in one central location, which inline CSS doesn't offer. It's easy for quickly prototyping styles, but shouldn't be used in production, especailly since it often leads to duplicating styles.
Embedded CSS centralizes the styles for the page, but it doesn't allow you to share styles across pages without copying the text of the embedded style and pasting it in each unique page on your site.
External CSS is the way to go, it has all of the advantages of embedded CSS but it allows you to share styles accross multiple pages.
Use external CSS when:
you have a lot of css code that will make your file messy if you put it all inline
you want to maintain a standard
look-and-feel across multiple pages
External CSS makes it a lot easier to manage your CSS and is the accepted way of implementing styles.
If the styles are only needed for one file, and you don't foresee that ever changing to apply to other pages, you can put your css at the top of the file (embedded?).
You should generally only use inline CSS if:
It's a one-time formatting for a specific tag
You want to override the default css (set externally or at the top of the file) for a specific tag
To everyone in the here and now, reading after 2015, with projects like Polymer, Browserify, Webpack, Babel, and many other important participants that I'm probably missing, we have been ushered into a new era of writing HTML applications, with regards to how we modularize large applications, distribute changes and compose related presentation, markup and behavior into self-contained units. Let's not even get started with service workers.
So before anyone forms an opinion on what is and isn't feasible, I would recommend that they investigate the current web ecosystem in their time to see if some issues related to maintainability have been gracefully solved.
Pros:
Allows you to control the layout of the entire site with one file.
Changes affect all documents at the same time.
Can eliminate redundant in-line styling (Font, Bold, Color, Images)
Provide multiple views of the same content for different types of users.
Cons:
Older browsers may not be able to understand CSS.
CSS is not supported by every browser equally.
In this case, the pros far outweigh the cons. In fact, if the site is designed in a specific way, older browsers will display the content much better (on average) than if the site were managed with tables.
If you are using a server side language, why not embed CSS and use conditional programming to display it as necessary? For example, say you're using PHP w/ Wordpress and you want some homepage specific CSS; you could use the is_home() function to show your CSS in the head of the document for that page only. Personally, I have my own template system that works like so:
inc.header.php = all the header stuff, and where page specific CSS would go I put:
if(isset($CSS)) echo $CSS;
Then, in a specific page template (say about.php), I would use a heredoc variable for the page specific CSS, above the line which includes the header:
Contents of about.php:
<?php
$CSS = <<< CSS
.about-us-photo-box{
/* CSS code */
}
.about-us-something-else{
/* more CSS code */
}
CSS;
include "inc.header.php"; // this file includes if(isset($CSS)) echo $CSS; where page-specific CSS would go ...
<body>
<!-- about us html -->
include "inc.footer.php";
?>
Is there something I'm missing that makes this approach inferior?
Pros:
1) I can still cache the page using standard caching techniques (is there a caching method that takes advantage of a CSS only external file??).
2) I can use php for special case conditional formatting in specific class declarations if absolutely necessary (PHP doesn't work in a CSS file, unless I'm missing some server directive I could set).
3) All my page specific CSS is extremely well organized in the actual PHP file in which it's being used.
4) It cuts down on HTTP requests to external files.
5) It cuts down on server requests to external files.
Cons:
1) My IDE program (Komodo IDE) can't follow the Heredoc formatting to properly highlight the CSS, which makes it slightly harder to debug syntax errors in the CSS.
2) I really can't see any other con, please enlighten me!