I have a SASS map of colors, and I want some of the colors to just reference another color from the map.
For example
$colors: (
special-red: #a82523,
red: special-red
)
However, when I run this, the value of map-get($colors, red) is literally special-red. I want the value to be #a82523.
How do you do this?
it's not possible, to add a key when your map is not event initialized. You can assign the value to a variable $special-red: #a82523; and then assign that in the map
$special-red: #a82523;
$colors: (
special-red: $special-red,
red: $special-red
)
But if you really want to do that, then you can create a mixin and look up through that
$colors: (
special-red: #009CDC,
red: special-red
);
#mixin themeColor1($color) {
$mapColor: map-get($colors, $color);
#if map-has($mapColor) {
color: map-get($colors, $mapColor)
} #else {
color: map-get($colors, $color)
}
}
.my-class {
#include themeColor1(red);
}
.my-class2 {
color: map-get($colors, special-red);
}
But my recommendation is approach 1, set variables
Related
I tried to change the variable used in another variable from the mixin, but I couldn't change the variable value.
$color: white !default;
$var: "this #{$color} is a test" ;
#mixin test($value, $color) {
// here how to override the $color value
color: $value;
}
.a {
#include test($var, #ccc);
}
By default the $color value is in white, and this $color variable is used in another variable $var.
When I pass the $var inside a mixin to change its variable ($color) value, it is not changed. Anyone please suggest the solution for this?
Expected Output:
.a {
color: "this #ccc is a test";
}
Thanks in advance.
When you pass the $var variable as the argument, its value is not updated because it has already been assigned. Passing a new $color variable in the mixin won't update the variable. A workaround can be by using the set-nth function to replace the white with the color passed in the mixin:
$color: white !default;
$var: #{$color}, red;
#mixin test($value, $colour) {
// here how to override the $color value
$var: set-nth($value, 1, $colour);
color: $var;
}
.a {
#include test($var, #ccc);
}
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've got list of colors and I would like to use darken() on them like so:
$innerPagesBgColors: "#6B46C1", "#2980B9", "#FD5456", "#000";
.foo {
color: darken(nth($innerPagesBgColors, 3), 5%);
}
But I get this error:
$color: "#FD5456" is not a color for `darken'
I tried interpolating the nth() portion but that didn't help either.
The problem is that darken function requires a color as first argument and, instead, you're trying to pass a string.
type-of(#6B46C1); // returns color
type-of("#6B46C1"); // returns string
So you should remove all quotes in $innerPagesBgColors:
$innerPagesBgColors: #6B46C1, #2980B9, #FD5456, #000;
In my case I solved with this.
#each $name, $color in $set_colors{
// check type-of before
#if (type-of($color) == 'color'){
.color-#{$name}{
color: #{$color};
}
.background-#{$name}{
background-color: $color;
&:hover{
background-color: darken($color, 10%);
}
}
}
}
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);
}