In my scss file I am importing a third-party css file
#import 'icons/third-party-icons/style';
Unfortunately, this style is missing the value for the color style
.mySelector {
content: "\eac2";
margin-left: -1em;
color: ;
}
As expected, node-sass is throwing the following error:
ModuleBuildError: Module build failed (from
./node_modules/sass-loader/lib/loader.js):
color: ;
^
Style declaration must contain a value
Is there any way to configure node-sass to ignore this invalid property?
In my opinion, that error report is there for a reason, you shouldn't have empty definitions as that is technically an error. In unminified CSS you wouldn't have an issue it would just appear as strikethrough in the element inspector in the browser, but in this case you break the minify process.
Instead of importing it you can download the CSS code if possible and save it in your project locally then solve the issues manually. It won't matter what you do later in your CSS file, the error will appear. Or else you can try to link the CSS in the header. If you are using PHP or similar serverside scripting then create a separate header.php (for example) and include it into every file. This way you will need to copy and paste the link once and you can access the style at every page.
You could override the imported css. The code is looking to use a value, but can't because it's null.
You could include in your style tags:
.mySelector {
color: black !important;
}
That !important will override whatever is imported from the stylesheet, and you class in the body will use that color instead of trying to use the null color.
How can I add CSS to github's markdown language?
I've been able to do so by using the style property inside html tags, like:
<p style="text-align: center;">This is some random text</p>
But if I move the css to the beginning, like:
<style>
p {
text-align: center;
}
</style>
<p>This is some random text</p>
Github doesn't recognize it, and just writes to the screen the css code.
I'm using Atom, and the package Markdown Preview actually recognizes this correctly, even though on the remote repository it shows wrong. And so does the Google Chrome extension Markdown Preview Plus.
Is there a way to do this? Writing css within html tags just feels plain wrong.
After GitHub converts Markdown to HTML,
The HTML is sanitized, aggressively removing things that could harm you and your kin—such as script tags, inline-styles, and class or id attributes. See the sanitization filter for the full whitelist.
style tags are not included in GitHub's whitelist, so they are removed. I'm actually surprised that inline style attributes work; they don't seem to be included in the whitelist, either, and are explicitly mentioned in the previous paragraph.
In any case, GitHub does not permit arbitrary HTML to be included in Markdown.
Here is how you can accomplish what you're looking for. As the other answer states, Github doesn't support this syntax, but if you pop this Markdown into another preview tool you'll see that the bullets are removed from this list.
|Signal|Description|
|---|---|
|DOP|Horizontal Dilution of precision|
|FIX|GPS Fix Quality indicator: <ul style="list-style-type:none;"><li>0 - fix not available</li><li>1 - GPS fix</li></ul>|
Signal
Description
DOP
Horizontal Dilution of precision
FIX
GPS Fix Quality indicator: 0 - fix not available1 - GPS fix
You can trivially override what CSS Github uses by supplying it with your own style.css file, nested as ./assets/css/style.css (which is stylesheet URL that gets pointed to in the HTML source code that Github build off of your markdown).
Note that if you want to just "add" any CSS, you'll want to copy Github's CSS first, so you can create a file with the same content after which you place your own rules. You can find this on any view-source:https://username.github.io/repo-name/assets/css/style.css with the obvious replacements for username and repo-name.
E.g.
/* CSS as copied from github's own stylesheet here, which is all one line anyway */
...
/* And then your own CSS */
/* remove the repo name as some kind of weird super-title */
h1:first-child { display: none }
/* and better emphasise the _real_ title */
h1:nth-child(2) { font-size: 3em; }
/* let's also give images a subtle border */
img { border: 1px solid #DDD; }
There are two CSS files referenced on the same page: A generic.css file and a custom.css file. The generic file has default styles in it that are overridden by the custom.css file for the same elements. This allows users of the site to customize or "skin" their pages without needing to recreate the entire generic.css file. Only a few styles would be overridden.
My question is the following: If the generic.css file has a style for an element with a background image and that same style is overridden in the custom.css with a different background image, is the first image ever downloaded by the browser?
Also, I want to find out if this is bad practice - customizing or "skinning" a generic CSS file with another custom CSS file to override a few styles, including specifying different background images.
While not totally definitive, this site ran some tests regarding this. The significant statement from that site that is related to your question is:
CSS images are kicked off not in the order in which they appear in the
CSS but in the order in which they’re called in the HTML. I’m not sure
of the precise moment when the download is initiated, but my guess is
that it happens just after the CSS rules have been matched, when the
property values are assigned to the DOM elements.
This at least tentatively confirms what I thought I remembered in the back of my mind reading on this a few years back, namely, that background images which are not ever displayed (as in the generic.css images being overridden by the custom.css images) are not ever downloaded.
Further confirmation of this would be the typical image preloader script that used to be so common prior to sprite images (and is still found in certain uses). It was designed to download images that would be used on :hover in css, because without it, the image would not load until the first hover was initiated, and this caused an unsightly delay. So that, also, argues for the fact that unless actually displayed (or preloaded), the background images themselves are never loaded.
I don't think there are generally any issues with "skinning," unless you are essentially overwriting most or all of the generic.css with custom.css, then one could argue, why load the generic at all. But as you said, normally there are just a few styles overwritten.
I think i answered NO and NO BAD PRACTICE. Because when the css file readable / executable by the browser, the browser will make comparisons to find the same value or the difference between css file and then combine them.
Easy example:
css1.css on file there is a line:
.test {display: block; width: 100%; height: 600px; background: #991100 url("image1.jpg") center top; border: 1px solid red;}
then the css2.css there is also the line:
.test {background: #991100 url("image2.jpg") no-repeat center center;}
the result of a combination that will be executed and run by the browser are:
.test {display: block; width: 100%; height: 600px; background: url("image2.jpg") no-repeat center center # 991100; border: 1px solid red}
where the "background: # 991100 url("image1.jpg") center top;" read but not called / executed by the browser.
Far as I know the value of the file css1.css be stacked by the value of the css2.css. What if there a css3.css file? then the file css3.css will also stacking on the combination of css1.css and css2.css.
Hope it helps.
I’m working on a CSS file that is quite long. I know that the client could ask for changes to the color scheme, and was wondering: is it possible to assign colors to variables, so that I can just change a variable to have the new color applied to all elements that use it?
Please note that I can’t use PHP to dynamically change the CSS file.
CSS supports this natively with CSS Variables.
Example CSS file
:root {
--main-color:#06c;
}
#foo {
color: var(--main-color);
}
For a working example, please see this JSFiddle (the example shows one of the CSS selectors in the fiddle has the color hard coded to blue, the other CSS selector uses CSS variables, both original and current syntax, to set the color to blue).
Manipulating a CSS variable in JavaScript/client side
document.body.style.setProperty('--main-color',"#6c0")
Support is in all the modern browsers
Firefox 31+, Chrome 49+, Safari 9.1+, Microsoft Edge 15+ and Opera 36+ ship with native support for CSS variables.
People keep upvoting my answer, but it's a terrible solution compared to the joy of sass or less, particularly given the number of easy to use gui's for both these days. If you have any sense ignore everything I suggest below.
You could put a comment in the css before each colour in order to serve as a sort of variable, which you can change the value of using find/replace, so...
At the top of the css file
/********************* Colour reference chart****************
*************************** comment ********* colour ********
box background colour bbg #567890
box border colour bb #abcdef
box text colour bt #123456
*/
Later in the CSS file
.contentBox {background: /*bbg*/#567890; border: 2px solid /*bb*/#abcdef; color:/*bt*/#123456}
Then to, for example, change the colour scheme for the box text you do a find/replace on
/*bt*/#123456
Yeeeaaahhh.... you can now use var() function in CSS.....
The good news is you can change it using JavaScript access, which will change globally as well...
But how to declare them...
It's quite simple:
For example, you wanna assign a #ff0000 to a var(), just simply assign it in :root, also pay attention to --:
:root {
--red: #ff0000;
}
html, body {
background-color: var(--red);
}
The good things are the browser support is not bad, also don't need to be compiled to be used in the browser like LESS or SASS...
Also, here is a simple JavaScript script, which changes the red value to blue:
const rootEl = document.querySelector(':root');
root.style.setProperty('--red', 'blue');
CSS itself doesn't use variables. However, you can use another language like SASS to define your styling using variables, and automatically produce CSS files, which you can then put up on the web. Note that you would have to re-run the generator every time you made a change to your CSS, but that isn't so hard.
You can try CSS3 variables:
body {
--fontColor: red;
color: var(--fontColor);
}
There's no easy CSS only solution. You could do this:
Find all instances of background-color and color in your CSS file and create a class name for each unique color.
.top-header { color: #fff; }
.content-text { color: #f00; }
.bg-leftnav { background-color: #fff; }
.bg-column { background-color: #f00; }
Next go through every single page on your site where color was involved and add the appropriate classes for both color and background color.
Last, remove any references of colors in your CSS other than your newly created color classes.
The 'Less' Ruby Gem for CSS looks awesome.
http://lesscss.org/
Yes, in near future (i write this in june 2012) you can define native css variables, without using less/sass etc ! The Webkit engine just implemented first css variable rules, so cutting edge versions of Chrome and Safari are already to work with them. See the Official Webkit (Chrome/Safari) development log with a onsite css browser demo.
Hopefully we can expect widespread browser support of native css variables in the next few months.
Do not use css3 variables due to support.
I would do the following if you want a pure css solution.
Use color classes with semenatic names.
.bg-primary { background: #880000; }
.bg-secondary { background: #008800; }
.bg-accent { background: #F5F5F5; }
Separate the structure from the skin (OOCSS)
/* Instead of */
h1 {
font-size: 2rem;
line-height: 1.5rem;
color: #8000;
}
/* use this */
h1 {
font-size: 2rem;
line-height: 1.5rem;
}
.bg-primary {
background: #880000;
}
/* This will allow you to reuse colors in your design */
Put these inside a separate css file to change as needed.
Sure can, sort of, thanks to the wonderful world of multiple classes, can do this:
.red {color:red}
.blackBack {background-color: black}
but I often end up combining them anyway like this:
.highlight {color:red, background-color: black}
I know the semantic police will be all over you, but it works.
I'm not clear on why you can't use PHP. You could then simply add and use variables as you wish, save the file as a PHP file and link to that .php file as the style sheet instead of the .css file.
It doesn't have to be PHP, but you get what I mean.
When we want programming stuff, why not use a programming language until CSS (maybe) supports things like variables?
Also, check out Nicole Sullivan's Object-oriented CSS.
You can group selectors:
#selector1, #selector2, #selector3 { color: black; }
You could pass the CSS through javascript and replace all instances of COLOUR1 with a certain color (basically regex it) and provide a backup stylesheet incase the end user has JS turned off
dicejs.com (formally cssobjs) is a client-side version of SASS. You can set variables in your CSS (stored in json formatted CSS) and re-use your color variables.
//create the CSS JSON object with variables and styles
var myCSSObjs = {
cssVariables : {
primaryColor:'#FF0000',
padSmall:'5px',
padLarge:'$expr($padSmall * 2)'
}
'body' : {padding:'$padLarge'},
'h1' : {margin:'0', padding:'0 0 $padSmall 0'},
'.pretty' : {padding:'$padSmall', margin:'$padSmall', color:'$primaryColor'}
};
//give your css objects a name and inject them
$.cssObjs('myStyles',myCSSObjs).injectStyles();
And here is a link to a complete downloadable demo which is a little more helpful then their documentation : dicejs demo
EDIT: This answer is no longer current. You should use CSS variables now.
Consider using SCSS. It's full compatible with CSS syntax, so a valid CSS file is also a valid SCSS file. This makes migration easy, just change the suffix. It has numerous enhancements, the most useful being variables and nested selectors.
You need to run it through a pre-processor to convert it to CSS before shipping it to the client.
I've been a hardcore CSS developer for many years now, but since forcing myself to do a project in SCSS, I now won't use anything else.
If you have Ruby on your system you can do this:
http://unixgods.org/~tilo/Ruby/Using_Variables_in_CSS_Files_with_Ruby_on_Rails.html
This was made for Rails, but see below for how to modify it to run it stand alone.
You could use this method independently from Rails, by writing a small Ruby wrapper script
which works in conjunction with site_settings.rb and takes your CSS-paths into account, and
which you can call every time you want to re-generate your CSS (e.g. during site startup)
You can run Ruby on pretty much any operating system, so this should be fairly platform independent.
e.g. wrapper: generate_CSS.rb (run this script whenever you need to generate your CSS)
#/usr/bin/ruby # preferably Ruby 1.9.2 or higher
require './site_settings.rb' # assuming your site_settings file is on the same level
CSS_IN_PATH = File.join( PATH-TO-YOUR-PROJECT, 'css-input-files')
CSS_OUT_PATH = File.join( PATH-TO-YOUR-PROJECT, 'static' , 'stylesheets' )
Site.generate_CSS_files( CSS_IN_PATH , CSS_OUT_PATH )
the generate_CSS_files method in site_settings.rb then needs to be modified like this:
module Site
# ... see above link for complete contents
# Module Method which generates an OUTPUT CSS file *.css for each INPUT CSS file *.css.in we find in our CSS directory
# replacing any mention of Color Constants , e.g. #SomeColor# , with the corresponding color code defined in Site::Color
#
# We will only generate CSS files if they are deleted or the input file is newer / modified
#
def self.generate_CSS_files(input_path = File.join( Rails.root.to_s , 'public' ,'stylesheets') ,
output_path = File.join( Rails.root.to_s , 'public' ,'stylesheets'))
# assuming all your CSS files live under "./public/stylesheets"
Dir.glob( File.join( input_path, '*.css.in') ).each do |filename_in|
filename_out = File.join( output_path , File.basename( filename_in.sub(/.in$/, '') ))
# if the output CSS file doesn't exist, or the the input CSS file is newer than the output CSS file:
if (! File.exists?(filename_out)) || (File.stat( filename_in ).mtime > File.stat( filename_out ).mtime)
# in this case, we'll need to create the output CSS file fresh:
puts " processing #{filename_in}\n --> generating #{filename_out}"
out_file = File.open( filename_out, 'w' )
File.open( filename_in , 'r' ).each do |line|
if line =~ /^\s*\/\*/ || line =~ /^\s+$/ # ignore empty lines, and lines starting with a comment
out_file.print(line)
next
end
while line =~ /#(\w+)#/ do # substitute all the constants in each line
line.sub!( /#\w+#/ , Site::Color.const_get( $1 ) ) # with the color the constant defines
end
out_file.print(line)
end
out_file.close
end # if ..
end
end # def self.generate_CSS_files
end # module Site
Not PHP I'm afraid, but Zope and Plone use something similar to SASS called DTML to achieve this. It's incredibly useful in CMS's.
Upfront Systems has a good example of its use in Plone.
If you write the css file as an xsl template, you could read color values from a simple xml file. Then create the css with an xslt processor.
colors.xml:
<?xml version="1.0"?>
<colors>
<background>#ccc</background>
</colors>
styles.xsl:
<?xml version="1.0"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:output method="text" version="1.0" encoding="iso-8859-1"/>
<xsl:template match="/">body {
background-color: <xsl:value-of select="/colors/background" />;
}
</xsl:template>
</xsl:stylesheet>
Command to render css: xsltproc -o styles.css styles.xsl colors.xml
styles.css:
body {
background-color: #ccc;
}
It’s not possible with CSS alone.
You can do it with JavaScript and LESS using less.js, which will render LESS variables into CSS live, but it’s for development only and adds too much overhead for real-life use.
The closest you can come with CSS is to use an attribute substring selector like this:
[id*="colvar-"] {
color: #f0c69b;
}
and set the ids of all your elements that you want to be adjusted to names starting with colvar-, such as colvar-header. Then when you change the color, all the ID styles are updated. That’s as close as you can get with CSS alone.