I am trying to change a variable's value in "../myStyle.scss" file from myComponent.ts . I read that it is impossible to achieve it because sass file are compiled into css by the sass pre-processor and the variable disapears. Isn't there a way to work this around.
My variable is called $theme.
And I want to change it's value.
$theme: #5A352A;
and I want it to become $theme: #ffffff; when the user clicks
You have to work in a different way.
Basically when you compile the angular app , it will generate a css file where it substitute the variable with the value , wherever you used it.
So if you want to achieve a color change you have to create a other variable and other classes and swipe it in your class attributes (this is one way, check also ngStyle and ngClass in angular reference).
For example white-theme/dark-theme (the most common case).
variables -> $black: #00000; $white: #ffffff
Example classes:
.body-dark {
background-color: $black;
}
.body-white {
background-color: $white;
}
and swipe the classes in the html elements.
setDark(){
document.getElementById("bodyId").setAttribute("class","body-dark ")
}
the same for white.
Apologies if this question has been asked or if there's a much better way to achieve my objective - I'm very new on the subject.
Using .scss within my React project I have a variable which is used in a number of visual elements as a highlight, eg.:
$theme = red;
.element{
color: $theme;
}
I'd like the user to be able to customize this to suit their tastes within the app client, however it is compiled down by sass-loader/style-loader to something like:
.element{
color: red;
}
which would require me to manually maintain a list of element classes to fire style edits at after the fact.
I am hoping that someone here knows a practical way to achieve what I'm after or, if that doesn't exist, could assist me with modifying sass-loader to also spit out a list of class names where the variable is used to a file that I can load post-compile.
You can use CSS variable instead.
Declare variables:
:root {
--theme-color: red;
}
... and then use it ...
#div1 {
background-color: var(--theme-color);
}
#div2 {
background-color: var(--theme-color);
}
Note: It does not work on Internet Explorer
https://caniuse.com/#search=css%20variables
Learn more about CSS variables
https://www.w3schools.com/css/css3_variables.asp
I have some css code in this format:
a { color: #333; background-color: #fff; }
a:visited { color: #aaa; background-color: #555; }
I want to get it in this format:
a {
color: #333;
background-color: #fff;
}
a:visited {
color: #aaa;
background-color: #555;
}
Is there an easy way to do that? I know I can write a macro to do that, but I was hoping there was a better/easier solution. Ideally, I'd like to be able to select the lines and do something like gq.
if the filetype has already been set as CSS, you can try:
:%s/[{;}]/&\r/g|norm! =gg
at least it works for your example:
You can use cssbeautify:
:%! css-beautify --file -
Not the definitive answer but something that might help get you in the right direction. I use a lot of vim files to sense check my code (different languages) and I have found with plugins I can copy my code in and have it nicely formatted on the fly (e.g. PEP-8 when doing python etc).
Hopefully this will be of some use to you: http://www.vim.org/scripts/script.php?script_id=2981
TotalOpinion - (Sorry!) -
Congratulations on choosing the king of all editors!
I've been working on this problem for a while. But in my case, I want to reformat the one-lined css file line by line, inspired by Kent's answer, I finally got this:
use visual mode to select a line or a few lines that you'd like to reformat
type '<,'>s/[{;}]/&\r/g|norm! v'<=
after you've done with the reformated css block, select only one css block in visual mode and press J (a capital j), then it'll become a nice one-line.
PS. Sorry about my poor English
The Kent's reply dopn't work well with file more complex like this : (W3C reference CSS)
I do it in a different way:
Split the big line in one rule per line:
%s/\(.\{-}{.\{-}}\)/\r\1/gc
Reformat: first step. For each rule put all properties in one line:
%s/\(.\{-}{\)\(.\{-}\)\(}\)/\1\r\t\2\r\3\r/gc
reformat: second step. Split properties one per line:
%s/;/;\r\t/gc
Maybe you can do it in less step, but this works fine.
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.
I just finished a medium sized web site and one thing I noticed about my css organization was that I have a lot of hard coded colour values throughout. This obviously isn't great for maintainability. Generally, when I design a site I pick 3-5 main colours for a theme. I end up setting some default values for paragraphs, links, etc... at the beginning of my main css, but some components will change the colour (like the legend tag for example) and require me to restyle with the colour I wanted. How do you avoid this? I was thinking of creating separate rules for each colour and just use those when I need to restyle.
i.e.
.color1 {
color: #3d444d;
}
One thing I've done here is break out my palette declarations from other style/layout markup, grouping commonly-colored items in lists, e.g.
h1 {
padding...
margin...
font-family...
}
p {
...
}
code {
...
}
/* time passes */
/* these elements are semantically grouped by color in the design */
h1, p, code {
color: #ff0000;
}
On preview, JeeBee's suggestion is a logical extension of this: if it makes sense to handle your color declarations (and, of course, this can apply to other style issues, though color has the unique properties of not changing layout), you might consider pushing it out to a separate css file, yeah. This makes it easier to hot-swap color-only thematic variations, too, by just targeting one or another colorxxx.css profile as your include.
That's exactly what you should do.
The more centralized you can make your css, the easier it will be to make changes in the future. And let's be serious, you will want to change colors in the future.
You should almost never hard-code any css into your html, it should all be in the css.
Also, something I have started doing more often is to layer your css classes on eachother to make it even easier to change colors once... represent everywhere.
Sample (random color) css:
.main_text {color:#444444;}
.secondary_text{color:#765123;}
.main_color {background:#343434;}
.secondary_color {background:#765sda;}
Then some markup, notice how I am using the colors layer with otehr classes, that way I can just change ONE css class:
<body class='main_text'>
<div class='main_color secondary_text'>
<span class='secondary color main_text'>bla bla bla</span>
</div>
<div class='main_color secondary_text>
You get the idea...
</div>
</body>
Remember... inline css = bad (most of the time)
See: Create a variable in .CSS file for use within that .CSS file
To summarize, you have three basic option:
Use a macro pre-processor to replace constant color names in your stylesheets.
Use client-side scripting to configure styles.
Use a single rule for every color, listing all selectors for which it should apply (my fav...)
I sometimes use PHP, and make the file something like style.css.php.
Then you can do this:
<?php
header("Content-Type: text/css");
$colour1 = '#ff9';
?>
.username {color: <?=$colour1;?>; }
Now you can use that colour wherever you want, and only have to change it in one place. This also works for values other then colours of course.
Maybe pull all the color information into one part of your stylesheet. For example change this:
p .frog tr.mango {
color: blue;
margin: 1px 3em 2.5em 4px;
position: static;
}
#eta .beta span.pi {
background: green;
color: red;
font-size: small;
float: left;
}
// ...
to this:
p .frog tr.mango {
color: blue;
}
#eta .beta span.pi {
background: green;
color: red;
}
//...
p .frog tr.mango {
margin: 1px 3em 2.5em 4px;
position: static;
}
#eta .beta span.pi {
font-size: small;
float: left;
}
// ...
You could have a colours.css file with just the colours/images for each tag in.
Then you can change the colours just by replacing the file, or having a dynamically generated CSS file, or having different CSS files available and selecting based upon website URL/subfolder/property/etc.
Or you can have colour tags as you write, but then your HTML turns into:
<p style="body grey">Blah</p>
CSS should have a feature where you can define values for things like colours that you wish to be consistent through a style but are defined in one place only. Still, there's search and replace.
So you're saying you don't want to go back into your CSS to change color values if you find another color 'theme' that might work better?
Unfortunately, I don't see a way around this. CSS defines styles, and with color being one of them, the only way to change it is to go into the css and change it.
Of course, you could build yourself a little program that will allow you to change the css file by picking a color wheel on a webpage or something, which will then write that value into the css file using the filesystemobject or something, but that's a lot more work than required for sure.
Generally it's better to just find and replace the colours you are changing.
Anything more powerful than that will be more complex with few benefits.
CSS is not your answer. You want to look into an abstraction on top of CSS like SASS. This will allow you to define constants and generally clean up your css.
Here is a list of CSS Frameworks.
I keep a list of all the colors I've used at the top of the file.
When the CSS is served by a server-side script, eg. PHP, usually coders make the CSS as a template file and substitute the colors at run-time. This might be used to let users choose a color model, too.
Another way, to avoid parsing this file each time (although cache should take care of that), or just if you have a static site, is to make such template and parse it with some script/static template engine before uploading to the server.
Search/replace can work, except when two initially distinct colors end up being the same: hard to separate them again after that! :-)
If I am not mistaken, CSS3 should allow such parametrization. But I won't hold my breath until this feature will be available in 90% of browsers surfing the Net!
I like the idea of separating the colour information into a separate file, no matter how I do it. I would accept multiple answers here if I could, because I like Josh Millard's as well. I like the idea of having separate colour rules though because a particular tag might have different colours depending on where it occurs. Maybe a combination of both of these techniques would be good:
h1, p, code {
color: #ff0000;
}
and then also have
.color1 {
color: #ff0000;
}
for when you need to restyle.
This is where SASS comes to help you.