I have two SASS functions that do the same thing, with some differences.
The first function iterates over the map, and then returns a short record so that you can conveniently use the work with color and transparency
// map
$colors: (
primary: #06285c,
seconadary: #96ccff,
tertiary: #357edd,
accent: #ff6300,
info: #a463f2,
success: #19a974,
warning: #ffde37,
danger: hsl(8deg 100% 61%)
);
#function color($key: primary, $opacity: 1) {
#return rgba(map-get($colors, $key), $opacity);
}
// sass style
background-color: color(warning, 0.6);
// compile to
background-color: rgba(255,0,0,.6);
My second function is designed to use whatever color is entered without having to rely on map
#function color-custom($key: primary, $opacity: 1) {
$color: color($key);
#return rgba($color, $opacity);
}
// sass style
background-color: color-custom(#ff0000, 0.6);
// compile to
background-color: rgba(255,0,0,.6);
I would just like to combine both functions into one. I do not know if this is possible, and how to check the dependencies inside the function. At the same time, these functions cannot exist, they give errors. Therefore, I would like to simply unite them, if it is possible.
You can check if $key exists in your map with map-has-key and then set a condition to return the correct result:
#function get-color($key: primary, $opacity: 1) {
$color: if(map-has-key($colors, $key), map-get($colors, $key), $key);
#return rgba($color, $opacity);
}
Related
I want to export "$var" like variables defined as "--var" variables from a Scss file to be used in other files with some scss functions such as "darken()", but it says its not a color.
I'm coding a Vue/Vite website and implementing a theme-change button, that will write data at the HTML tag, and use it to define the theme.
<html lang="en" data-theme="dark"> ... </html>
The base.scss looks like this:
[data-theme="dark"] {
--primary: #c6c7df;
--secondary: #c95d63;
--text-light: #e2ebf5;
}
[data-theme="light"] {
--primary: #26298d;
--secondary: #c95d63;
--text-light: #2c3e50;
}
$primary: var(--primary);
$secondary: var(--secondary);
$text-light: var(--text-light);
I can use the "$var"-like variable at the end of the file, but when I use it inside a "darken($primary, 10%)" function, it gives the following error:
Error: $color: var(--primary) is not a color.
I know it's because I defined it as a CSS variable but if I define the variable inside the "[theme] {}" thing, it doesn't get innitialized and throws the error "Undefined variable"
I know it's a niche question, and I could use something like this, but I wish I could just export it as a scss variable.
Thank you very much.
Of course we cannot make a CSS variable lighten or darken. Think about, What will happen to the Name of CSS variable in the output?
So we have to define all CSS variables and assign desired colors, Before using them.
Solution
For this purpose, you can automatically create the list of CSS variables by #each and create a manual function by #function for easy use. This way gives us a standard css output and the best experience in Sass coding.
// Theme defines area:
$theme-colors:(
"primary": #940fe0,
"secondary": #e49f38,
"warning": #ffe600,
"info": #165ad6
);
$darken-percent: 20%;
$lighten-percent: 20%;
// Functions area:
:root {
#each $name, $color in $theme-colors {
$lighten: lighten($color, $lighten-percent);
$darken: darken($color, $darken-percent);
--color-#{$name}: #{$color};
--color-#{$name}-light: #{$lighten};
--color-#{$name}-dark: #{$darken};
}
}
#function cl($name, $color-tone) {
#if not map-get($theme-colors, $name+''){
#error "`#{$name}` is not defined in Colors Theme";
}
#if $color-tone == d {
#return var(--color-#{$name}-dark);
}
#if $color-tone == l {
#return var(--color-#{$name}-light);
}
#else{
#return var(--color-#{$name});
}
}
// Our custom function usage:
// Use 'b' to return Base color. Ex: cl(primary,b)
// Use 'l' to return Lighten color. Ex: cl(primary,l)
// Use 'd' to return Darken color. Ex: cl(primary,d)
.test {
color: cl(primary,b);
color: cl(warning,l);
}
Compiled css result:
:root {
--color-primary: #940fe0;
--color-primary-light: #bf61f4;
--color-primary-dark: #550980;
--color-secondary: #e49f38;
--color-secondary-light: #f0ca92;
--color-secondary-dark: #a06916;
--color-warning: #ffe600;
--color-warning-light: #fff066;
--color-warning-dark: #998a00;
--color-info: #165ad6;
--color-info-light: #6395ef;
--color-info-dark: #0c337a;
}
.test {
color: var(--color-primary);
color: var(--color-warning-light);
How can I make the following code more DRY?
I have setup bunch of variables below that are later referenced in a $colors map. Currently I have to edit the code in two places to add a new color to the system. And these variable number will grow in the future considerably.
https://codepen.io/umbriel/pen/LLvPPK
Here is the whole current code section
$red : #cc0000;
$blue : #1e8cea;
$green : #27a249;
$teal : #41bdbb;
$purple : #5c369e;
$-yellow : #ecd340;
#function color-palette($color) {
$map: (
light: scale-color($color, $lightness: 88%),
lighter: adjust-hue(scale-color($color, $lightness: 48%, $saturation: 32%), -8%),
base: $color,
darker: adjust-hue(scale-color($color, $lightness: -36%), 0%),
dark: scale-color($color, $lightness: -72%, $saturation: 100%)
);
#return $map;
}
$colors: (
red: color-palette($red),
blue: color-palette($blue),
green: color-palette($green),
teal: color-palette($teal),
purple: color-palette($purple),
yellow: color-palette($yellow)
);
// retrieve color from map ie. `color(primary, base)`
#function color($color-name, $color-variant:null) {
// color variant is optional
#if ($color-variant != null) {
// map inception
#return map-get(map-get($colors, $color-name), $color-variant);
} #else {
#return map-get(map-get($colors, $color-name), base);
}
}
I have tried looping the map inside the $colors map which didn't work.
$colorvars : (
red : #cc0000,
blue : #1e8cea,
green : #27a249,
teal : #41bdbb,
purple : #5c369e,
yellow : #ecd340
)
$colors: (
#each $key, $value in $colorsvars {
$key : color-palette($value)
}
)
DRY adding colors (and its variations):
There's an excellent article that describe how to do it better than I could ever explain. Basically you create a list of colors, then list of variations that contains what function should be applied to modify color and parameters for that function. Finally you kind of create an interface/one simple to use function for getting final color value. The important thing is that all colors and possible variations are declared in one place.
DRY generating selectors:
Another thing you might consider is the way to generate all these selectors. You could use #each directive to go through all colors and variations and generate all selectors/classes in 1 place. Something like:
#each $color in $colors {
#each $variation in $variations {
.c-#{$color}-#{$variation} {
background-color: a-nice-function-to-get-color($color, $variation);
}
}
}
However, this usually isn't such a great idea, as it makes searching selectors in your IDE way harder. If you're really going to have so many different colors, then it might be worth thinking about using this technique, though.
TL;DR: How can you use SCSS to have CSS variables with a fallback for older browsers.
I'm trying to make sense of this article. In my opinion, you have to already be an advanced SASS user to understand it, which I'm not. To make matters worse, it's the only article I found on the subject.
Here is what I'm trying to achieve:
My scss should be along the lines of :
body {
#include v(background-color, primary)
}
then the processed CSS should be
body{
background: yellow; /* Yellow being defined above as the primary color */
background: var(--color-primary);
}
By playing around a bit, I can already get the value of the CSS variable like so:
$colors: (
primary: yellow,
);
:root {
#each $name, $color in $colors {
--color-#{$name}: $color;
}
}
#mixin background-color($color_) {
background: var(--color-#{$color_});
}
To use it:
body{
#include background-color(primary);
}
Which will result in this:
body {
background: var(--color-primary);
/* But the fallback is missing :(, I tried things with the map-get but it's really eluding me... */
}
If you're using Sass, you can automate fallbacks through a Sass mixin. Create a map of your CSS variable names and their values, and then you can look up those values in a mixin that outputs the fallback style and the preferred one
$vars: (
primary: yellow,
);
:root {
--primary: map-get($vars, primary);
}
#mixin var($property, $varName) {
#{$property}: map-get($vars, $varName);
#{$property}: var(--#{$varName});
}
The above mixin is used like so:
body {
#include var(background-color, primary);
}
and outputs the following CSS:
:root {
--primary: yellow;
}
body {
background-color: yellow;
background-color: var(--primary);
}
Et voilà :)
Update: Postcss Custom properties can do fallback and is way easier than the below code
step 1: declare scss variables
So first of all we want to put some variables in a $map, I'll go with color variables:
$colors: (
primary: #FFBB00,
secondary: #0969A2
);
step 2: automate css 4 var generation
// ripped CSS4 vars out of color map
:root {
// each item in color map
#each $key, $value in $colors {
--colors-#{$key}: $value;
}
}
What happens in root is : for each key and value in the colors map, we print the followng :
--colors-#{$key}: $value;
Which corresponds to css variable declarations. I believe the weird bit with #{} around the key is to not have spaces around the value.
Thus the result is:
--colors-primary: #FFBB00,
--colors-secondary: #0969A2
Note that the prefix (--colors-) is the same name as the scss color map above it. The why will become clear in last step.
step 3: Plenty of maps !
$props: (
background-color: $colors
);
$map-maps: (
background-color: colors
);
Here we add the map $props which maps a css property to the map containing the values. background-color will hold color, so the correct map is $colors.
map-maps is a copy of props where instead of the map we have the name of said map. (this is relative to the note in step 2).
Step 4 : let's make it work !
#mixin v($prop, $var) {
// get the map from map name
$map: map-get($props, $prop);
// fallback value, grab the variable's value from the map
$var-fall: map-get($map, $var);
// our css4 variable output
$var-output: var(--#{$map}-#{$var});
#{$prop}: $var-fall;
// css4 variable output
#{$prop}: $var-output;
}
body{
#include v(background-color, primary);
}
I simplified the code in the article quite a bit, it still works, for this example at least, the code in the article takes more into account.
Anyhow, here is what happens.
First, we call the mixin with:
#include v(background-color, primary);
Then upon entering,
$map: map-get($props, $prop); // map-get($props, background-color)
we have a variable called $map to which we assign the value that is inside the $props map at the key background-color which happen to be the $colors map. It's a bit of a maze but it's not that complicated once you resolve it.
Then for the fallback:
$var-fall: map-get($map, $var);
This simply gets the value of the map we just got (which is $colors) at the $var key (which happens to be primary). Thus the result is #FFBB00.
For the css var
$map-name: map-get($map-maps, $prop);
$var-output: var(--#{$map-name}-#{$var});
we recreate what we did to generate the var in the #each loop
Whole code would be :
$colors: (
primary: #FFBB00,
secondary: #0969A2
);
// ripped CSS4 vars out of color map
:root {
// each item in color map
#each $name, $color in $colors {
--colors-#{$name}: $color;
}
}
$props: (
background-color: $colors,
color: $colors
);
$map-maps: (
background-color: colors
);
#mixin v($prop, $var) {
// get the map from map name
$map: map-get($props, $prop);
// fallback value, grab the variable's value from the map
$var-fall: map-get($map, $var);
// our css4 variable output
$map-name: map-get($map-maps, $prop);
$var-output: var(--#{$map-name}-#{$var});
#{$prop}: $var-fall;
// css4 variable output
#{$prop}: $var-output;
}
body{
#include v(background-color, primary);
}
Now this is a simplification of what is done in the article. You should check it out to have code a bit more robust.
I assume you are aware of the reason why it didn't show the fallback. But since it's an answer I will explain the reasons
The current mixin block has only one background property which makes the sass compiler to generate only one property. I don't think sass can identify whether 'var' is supported in browser or not. So, we have to explicitly specify if we need the fallback.
Since you already have the map all you need is to get the value by giving the key 'primary'
#mixin background-color($color_) {
background: var(--color-#{$color_});
background: map-get($colors, primary);
}
This will add the background: yellow to the body class always. Alternatively if you want to control the addition of the fallback based on condition. You can do like this
#mixin background-color($color_, $showFall) {
background: var(--color-#{$color_});
#if $showFall {
background: map-get($colors, primary);
}
}
and call like this
body{
#include background-color(primary, true);
}
Code pen for the same
https://codepen.io/srajagop/pen/xdovON
Note: I am writing the answer under the assumption that you want only the background-color to work and not all the other properties like mentioned in that post. For that you need to create a proper data structure
Google Materialize defines their color variables in this file like so:
$red: (
"lighten-5": #FFEBEE,
"lighten-4": #FFCDD2,
"lighten-3": #EF9A9A,
"lighten-2": #E57373,
"lighten-1": #EF5350,
"base": #F44336,
"darken-1": #E53935,
"darken-2": #D32F2F,
"darken-3": #C62828,
"darken-4": #B71C1C,
"accent-1": #FF8A80,
"accent-2": #FF5252,
"accent-3": #FF1744,
"accent-4": #D50000
);
I would like to use the colors with something like this:
.light-red-border {
border: 1px solid $red-lighten-1;
}
How do I call those variables directly? They're used in other I can't find anything on this syntax mentioned anywhere.
Edit: I looked around a bit more in the Materialize Github and found some examples in _variables.scss:
$primary-color: color("materialize-red", "lighten-2") !default;
$primary-color-light: lighten($primary-color, 15%) !default;
$primary-color-dark: darken($primary-color, 15%) !default;
However, if you can direct me to an article discussing the syntax used to define the variables I would greatly appreciate it.
You're looking for map-get($red, 'lighten-5'); if you simply want the corresponding value from this map.
To expand on #weirdpanda's answer, these SASS maps need to be iterated upon, which then compiles into more CSS rules.
In the file you linked to, each of those colors is placed in a larger map of $colors:
$colors: (
"materialize-red": $materialize-red,
"red": $red,
"pink": $pink,
"purple": $purple
//...
);
This colors map is then iterated upon, producing matching class selectors like red.lighten-5 in the CSS.
#each $color_name, $color in $colors {
#each $color_type, $color_value in $color {
#if $color_type == "base" {
.#{$color_name} {
background-color: $color_value !important;
}
.#{$color_name}-text {
color: $color_value !important;
}
}
#else {
.#{$color_name}.#{$color_type} {
background-color: $color_value !important;
}
.#{$color_name}-text.text-#{$color_type} {
color: $color_value !important;
}
}
}
}
To actually use these variables within SASS files (for instance, after importing _color.scss, you can access a map value with map-get($map, $key). For instance:
.my-class{
color: map-get($red, 'lighten-5');
}
Edit: regarding the color function: The $primary-color: color("materialize-red", "lighten-2") line you posted is using a function defined in _color.scss, which ostensibly does the same thing as map-get but checks if the key exists in the map with map-has-key and raises a warning if it cannot be found.
#function color($color, $type) {
#if map-has-key($colors, $color) {
$curr_color: map-get($colors, $color);
#if map-has-key($curr_color, $type) {
#return map-get($curr_color, $type);
}
}
#warn "Unknown `#{name}` in $colors.";
#return null;
}
This syntax notation is called the SASS Maps notation and it is the SASS-equiv of a hash-map. Read more about it here.
I’ll start with my code, as it should be easier to understand what I want to do:
#function get-color($color, $lightness) {
#return map-get(map-get($colors, $color), $lightness);
}
$colors: (
green: (
light: #A4EDE1,
mid: darken(get-color(green, light), 20%),
dark: darken(get-color(green, mid), 20%)
),
red: (
light: complement(get-color(green, light)),
mid: complement(get-color(green, mid)),
dark: complement(get-color(green, dark))
)
);
As you can see, I have created a multidimensional map, with my color values.
At the moment, I want to create the other colors, through the darken() and the complement() functions.
The problem with that is, that I need to reference variables inside of the $colors variable, before it is completely filled. This results in an error for my get-color() function, which tells me, there is no $colors variable.
I know it would be possible to alter the colors outside of my $colors map, but the benefit of doing it this way is, that I can always come back and define color values, that are not generated. This would be a huge benefit in maintaining the project.
So here my question: Is there any way to reference another variable in map, before the whole map is defined?
No. The mapping isn't defined until you reach that semicolon at the end. So you cannot reference any portion of it until then.
$base-color: #A4EDE1;
$colors: (
green: (
light: $base-color,
mid: darken($base-color, 20%),
dark: darken($base-color, 40%)
),
);
$colors: map-merge($colors, (
red: (
light: complement(get-color(green, light)),
mid: complement(get-color(green, mid)),
dark: complement(get-color(green, dark))
)));
.foo {
color: get-color(red, mid);
}
Unless you're looping over the mapping, I would recommend not using mappings to store your color variables. Rather, it would be better to simply write a function that will do the manipulation for you:
$base-color: #A4EDE1;
#function get-color($lightness, $variation: null, $color: $base-color) {
$color: if($variation, call($variation, $color), $color);
#if $lightness == medium {
#return darken($color, 20%);
} #else if $lightness == dark {
#return darken($color, 40%);
}
#return $color;
}
.foo {
color: get-color(mid);
border: 1px solid get-color(mid, complement);
}