Exclude elements from group in SCSS - css

Imagine a set of rules like the ones shown below:
span, div { color: red; }
span { background: white; }
div { background: black; }
Is it possible to wrap them under 1 SCSS rule? Something in the form of:
span, div {
& { color: red; }
&:not(div) { background: white;}
&:not(span) { background: black; }
}
Unfortunately an approach like this could very easily get quite large. So I'm hoping for an SCSS implementation of the code shown at the top but without the use of :not(<every other selector>).
Preferably something looking like (invalid code):
span, div {
& { color: red; }
&(span) { background: white;}
&(span) { background: black; }
}

I don't think that it is possible to do what you want this way (but I may be wrong).
The code below achieve the result you are looking for but uses a map, a #mixin and #extend instead of a single selector. Maybe it's a bit too complex for want you want to achieve but I hope it can help:
#mixin setSelectors($elements) {
%commonProperties {
#content;
}
#each $selector, $properties in $elements {
#{$selector} {
#extend %commonProperties;
#each $property, $value in $properties {
#{$property}: #{$value};
}
}
}
}
#include setSelectors((
span: (background: white),
div: (background: black)
)) {
color: red; // Common properties
}
Will return:
div, span { color: red; }
span { background: white; }
div { background: black; }
The first argument is a map containing all your selectors and their specific properties. The #content of the #mixin contains shared properties.
If you need to add a selector that doesn't have any specific property, you can add it to the map with null as key. Such as:
#include setSelectors((
span: (background: white),
div: (background: black),
i: null
)) {
color: red;
}
However, this solution doesn't allow nested selectors so I believe that separating the selectors is the best way to go.

Related

Button-Color based on className in scss

Is there a neat, simple and beautiful way to implement something like this in scss:
&.red{
--color:red;
}
&.green{
--color:green;
}
&.blue{
--color:blue;
}
&.yellow{
--color:yellow;
}
[...]
background-color:var(--color);
i was thinking something like this:
&.$color{
--color:$color
}
im really new into scss and wanted to know if this is possible in some way.
It sounds like you want to loop through a list of colors to generate new classes, which is definitely doable with proper interpolation:
.button {
$colors: red, green, blue, yellow; // create a list of colors
#each $color in $colors { // loop through each value of a list
&.#{$color} { // need interpolation to use a sass variable in a css selector
--color: #{$color}; // need interpolation for css variable assignment
color: $color; // do not need interpolation for other css properties.
}
}
}
That will output the following compound selectors, based on the $colors list.
.button.red {
--color: red;
color: red;
}
.button.green {
--color: green;
color: green;
}
.button.blue {
--color: blue;
color: blue;
}
.button.yellow {
--color: yellow;
color: yellow;
}
However, since you're already generating classes from a list, I'd suggest creating new class names rather than compound selectors, since these increase specificity. By changing &.#{$color} to &--#{$color} in the loop above, you can get the following BEM-style classes:
.button--red {
--color: red;
color: red;
}
.button--green {
--color: green;
color: green;
}
/* etc. */

Set a SASS variable depending

I'm searching a way to use a particular color depending on a class on the body tag.
I have a main scss file like this
// variables.scss
$bg-main: white;
$color-first: red;
$color-second: green;
And in my other files, I use the colors
// content.scss
.content {
.some-selector: {
// some styles
color: $color-second;
}
a:hover {
// some styles
color: $color-second;
}
}
// and same goes for menu.scss etc.
Now I have a dynamic class on the body, that changes depending on the current selected menu. I would like $color-second to be different for each body classes, and I don't know how to do that. The only solution I found was to move all the $color-second from each files into one single file, like this:
.body-1 {
.content a:hover, .content .some-selector {
color: green;
}
}
.body-2 {
.content a:hover, .content .some-selector {
color: blue;
}
}
.body-1 {
.content a:hover, .content .some-selector {
color: black;
}
}
So I don't need to write the color in each files. This works well, but if I need to set this $color-second to some other selector, I need to put that in this big file.
Is this possible to do this an other way?
I already checked these answers, but it didn't helped me much:
SASS set variable depending on CSS class
Creating or referencing variables dynamically in Sass
Merge string and variable to a variable with SASS
There are multiple ways to do this. The most obvious two which come to mind are mixins and loops:
Mixins
Just put everything you want into a single mixin, and then use it for every body class:
#mixin colored-content($color) {
.content a:hover, .content .some-selector {
color: $color;
}
/* Any other rules which use $color here */
}
.body-1 {
#include colored-content(green);
}
.body-2 {
#include colored-content('#FF0000');
}
.body-3 {
#include colored-content(darken(red, 20));
}
You can extend this example with any number of arguments (for example, $textColor and $bgColor), conditions or rules.
With this approach you will not have SCSS code repetitions, and any updates will be introduced easily.
Loop
Another way is to use a simple loop:
$body_themes: (
"body-1": green,
"body-2": #FF0000,
"body-3": darken(red, 2)
);
#each $body_class, $color in $body_themes {
.#{$body_class} {
.content a:hover, .content .some-selector {
color: $color;
}
/* Any other rules which use $color here */
}
}
It is even shorter, but imho it is less readable.
P.S. It is possible to combine mixins and loops, by the way :)

SCSS. Reference second level ascending selector

One of the techniques to organise classes in the scope of avoiding collisions, is to extend a parent's class + add some suffix. For example:
<div class="a">
<div class="a__b">
<div class="a__c">
<span class="a__d">
From considerations of not duplicating code, in sass/scss files, one can refer a parent with the help of an ampersand - &, so above structure can be achieved like this:
.a{
&__b{}
&__c{}
&__d{}
Which is transfomed into:
.a__b {}
.a__c {}
.a__d {}
But difficulties appear when one needs to get such a css as the result:
.a:hover{
color: red;
}
.a:hover .a__b{
color: blue;
}
Since the main idea is not to duplicate selectors, a question appears - is there a way to reference second level parent? I know that && ins't an issue but is there a way to simulate double ampersand behaviour?
.a{
&:hover{
color: red;
& __b { /* & -> .a:hover, but I need just .a */
color: blue;
}
}
}
Not an issue, .a is duplicated:
.a:hover { //here
color: red;
.a__b { //here
color: blue;
}
}
Also not an issue:
.a { //ok
&:hover {
color: red;
.a__b { //oops, duplicated selector
color: blue;
}
}
}
So, from the considerations of avoiding collisions many times classes have long names. And that is when duplicated selectors make code look scary. Imagine, that instead of .a selector there would be: .custom-layers-list-panel-conatiner. Another reason of avoiding duplicated classes is that if parent class is changed, it should be changed everywhere. Yes, nowadays it's quite trivial task with some specific tools, but it's still remains a place where mistakes can appear.
Update: better than Original
.a{
$grandparent: &;
&:hover{
color: red;
& #{$grandparent}__b {
color: blue;
}
}
}
and
Original:
#function r-pseudo($s) {
$string: nth(nth($s, 1), 1);
#return str-slice($string, 0, str-index($string, ':') - 1);
}
.a{
&:hover{
color: red;
& #{r-pseudo(&)}__b {
color: blue;
}
}
}
both generate
.a:hover {
color: red;
}
.a:hover .a__b {
color: blue;
}
Your idea was right, but you've to put the a:hover to the top-level to get the result you wanted. It is nothing what you wanted, but the only way that SCSS will give you your target-result.
I think you looking for this:
.a:hover {
color: red;
.a__b {
color: blue;
}
}
Second try, like this?
.a {
&:hover {
color: red;
.a__b {
color: blue;
}
}
}

Scoping sass variable

Is there a way to add scope to sass variables?
I want to be able to attach a class to my body element. The class will refer to a set of colours that the rest of the stylesheets can access.
I have tried:
#mixin theme_one{
$color: #000;
}
.theme_one{
#include theme_one;
}
and
.theme_one{
$color: #000;
}
I've just come across the same issue myself. I wanted to have different colour themes for different sections of my site.
Using a mixin seems like the best way to go. It's nicely DRY, and easy to use. The trick is not setting your colours in your main styles blocks, but rather using only the mixin for this.
I've set up the theme colours as variables at the top so they can be edited nicely, and I've set them as lists so that multiple values can be passed without hordes of variable being defined.
So:
// Variable Definitions
$defaultColor: black white grey;
$color2: blue green brown;
$color3: red white blue;
#mixin colorSet($color: $defaultColor) {
$link: nth($color, 1);
$border: nth($color, 2);
$background: nth($color, 3);
border-color: $border;
background-color: $background;
.column {
border-color: lighten($border, 10%);
}
a {
color: $link;
&:hover {
color: darken($link, 15%);
}
}
}
// Default colours
body {
#include colorSet();
}
// Scoped colours
.my-theme-3 {
#include colorSet($color3);
}
.my-theme-2 {
#include colorSet($color2);
}
Will produce something like this:
body {
border-color: white;
background-color: grey; }
body .column {
border-color: white; }
body a {
color: black; }
body a:hover {
color: black; }
.my-theme-3 {
border-color: white;
background-color: blue; }
.my-theme-3 .column {
border-color: white; }
.my-theme-3 a {
color: red; }
.my-theme-3 a:hover {
color: #b30000; }
.my-theme-2 {
border-color: green;
background-color: brown; }
.my-theme-2 .column {
border-color: #00b300; }
.my-theme-2 a {
color: blue; }
.my-theme-2 a:hover {
color: #0000b3; }
Edit: Updated to use default mixin values.
In your case no need to use mixin, If you have set of many styles then use mixin,
ie. if you have
#mixin theme_one{
$color: #000;
height: 50px;
}
then use Mixin
otherwise for single property use only variable
$color: #fff;
.some_class01{
color: $color;
background: $color;
}
.some_class22{
border-color: $color;
}
IMP: Variable should assign at the top of your code, it means don't use it after/below where you assigned it :)
Not sure if this is what you are looking for. It looks like you may have tried something similar to this,
which should probably work. (it may just be a matter of using !default)
Your body tag with a class on it..
<body class="theme_one">
</body>
Sass variables defined in stylesheet..
//THEME ONE VARIABLES
.theme_one{
$borderColor:#333 !default;
$fontColor:#999 !default;
}
//THEME TWO VARIABLES
.theme_two{
$borderColor:#CCC !default;
$fontColor:#000 !default;
}
Pre-existing CSS which will be overwritten depending on which class is used on the body tag.
h1.someheader {
color:$fontColor;
border-bottom:1px solid;
border-color:$borderColor;
}
Otherwise you could maybe try something like this. It looks like you may have tried something similar, however there seems to be an error with your mixin ... see note below.
//mixin used to set variables for properties
#mixin themeOne($fontColor,$borderColor) {
color:$fontColor;
border-color:$borderColor;
}
#include themeOne(#000,#CCC);
Pre-existing CSS
h1.someheader {
color:$fontColor
border-color:$borderColor;
border-bottom:1px solid;
}
Also note in your mixin example you are using $color:#000; ... This won't be interpreited properly as it should be color:#000; You can't use variables as selectors
unless you do something like #{$color}:#000;
I haven't quite tested this yet, so some things might need to be adjusted. If this doesn't solve your problem I hope it at least gives you some ideas.

SASS CSS: Target Parent Class from Child

I am using SASS and found an inconvenience. This is an example of what I am trying to do:
.message-error {
background-color: red;
p& {
background-color: yellow
}
}
Expected CSS:
.message-error {
background-color: red;
}
p.message-error {
background-color: yellow ;
}
The idea: all elements with .message-error will be red, except if it is p.message-error. This is not real-life situation, just to show an example.
SASS is not able to compile this, I even tried string concatenation. Is there some plugin that will do exactly the same?
NOTE:
I know I can put another CSS definition like:
p.message-error{....}
...under, but I would like to avoid that and use one place for all .message-error definitions.
Thanks.
As of Sass 3.4, this is now supported. The syntax looks like this:
.message-error {
background-color: red;
#at-root p#{&} {
background-color: yellow
}
}
Note the #at-root directive and the interpolation syntax on the ampersand. Failure to include the #at-root directive will result in a selector like .message-error p.message-error rather than p.message-error.
You can assign the current selector to a variable and then use it at any depth:
.Parent {
$p: &;
&-Child {
#{$p}:focus & {
border: 1px solid red;
}
#{$p}--disabled & {
background-color: grey;
}
}
}
Natalie Weizenbaum (the lead designer and developer of Sass) says it will never be supported:
Currently, & is syntactically the same as an element selector, so it
can't appear alongside one. I think this helps clarify where it can be
used; for example, foo&bar would never be a valid selector (or would
perhaps be equivalent to foo& bar or foo &bar). I don't think this use
case is strong enough to warrant changing that.
Source: #282 – Element.parent selector
To my knowledge, there is no possible workaround.
The best thing to do would be probably this (assuming you have a little more in your .message-error class than just background color.
.message-error {
background-color: red;
}
p.message-error {
#extend .message-error;
background-color: yellow
}
This approach doesn't offer that close grouping, but you can just keep them close to each other.
I had the same problem so I made a mixin for that.
#mixin tag($tag) {
$ampersand: & + '';
$selectors: simple-selectors(str-replace($ampersand, ' ', ''));
$main-selector: nth($selectors, -1);
$previous-selectors: str-replace($ampersand, $main-selector, '');
#at-root {
#{$previous-selectors}#{$tag}#{$main-selector} {
#content;
}
}
}
To make it work, you will need a string replacement function as well (from Hugo Giraudel):
#function str-replace($string, $search, $replace: '') {
$index: str-index($string, $search);
#if $index {
#return str-slice($string, 1, $index - 1) + $replace + str-replace(str-slice($string, $index + str-length($search)), $search, $replace);
}
#return $string;
}
How it works:
SCSS
.foo {
color: blue;
#include tag(p) {
color: red;
}
}
Output
.foo {
color: blue;
}
p.foo {
color: red;
}
Use case
This method works with nested selectors but not whit compound ones.
#Zeljko It is no possible to do what you want via SASS.
See Nex3 comment: https://github.com/nex3/sass/issues/286#issuecomment-7496412
The key is the space before the '&':
.message-error {
background-color: red;
p & {
background-color: yellow
}
}
instead of:
.message-error {
background-color: red;
p& {
background-color: yellow
}
}
I think if you want to keep them grouped by parent selector, you might need to add a common parent:
body {
& .message-error {background-color: red;}
& p.message-error {background-color: yellow}
}
Of course, body could be replaced with some other common parent, such as #Content or another div name that will contain all the error messages.
UPDATE (Another Idea)
If you leverage #for and lists then it seems like this should work (what I don't know for sure is if the list will allow the . (period).
#for $i from 1 to 3 {
nth(. p. ul., #{$i})message-error {
background-color: nth(red yellow cyan, #{$i}));
}
}
Should compile to something like:
.message-error {
background-color: red;}
p.message-error {
background-color: yellow;}
ul.message-error {
background-color: cyan;}
I made a mixin that solves this problem.
Github: https://github.com/imkremen/sass-parent-append
Example: https://codepen.io/imkremen/pen/RMVBvq
Usage (scss):
.ancestor {
display: inline-flex;
.grandparent {
padding: 32px;
background-color: lightgreen;
.parent {
padding: 32px;
background-color: blue;
.elem {
padding: 16px;
background-color: white;
#include parent-append(":focus", 3) {
box-shadow: inset 0 0 0 8px aqua;
}
#include parent-append(":hover") {
background-color: fuchsia;
}
#include parent-append("p", 0, true) {
background-color: green;
}
}
}
}
}
Result (css):
.ancestor {
display: inline-flex;
}
.ancestor .grandparent {
padding: 32px;
background-color: lightgreen;
}
.ancestor .grandparent .parent {
padding: 32px;
background-color: blue;
}
.ancestor .grandparent .parent .elem {
padding: 16px;
background-color: white;
}
.ancestor:focus .grandparent .parent .elem {
box-shadow: inset 0 0 0 8px aqua;
}
.ancestor .grandparent .parent:hover .elem {
background-color: fuchsia;
}
.ancestor .grandparent .parent p.elem {
background-color: green;
}
I created package/mixin with a similar solution :) (Maybe it will help U)
https://github.com/Darex1991/BEM-parent-selector
so writing:
.calendar-container--theme-second-2 {
.calendar-reservation {
#include BEM-parent-selector('&__checkout-wrapper:not(&--modifier):before') {
content: 'abc';
}
}
}
This mixin will add selector only for the last parent:
.calendar-container--theme-second-2 .calendar-reservation__checkout-wrapper:not(.calendar-reservation--modifier):before {
content: 'abc';
}
More info on the repo.
I have ran into this before as well. Bootstrap 3 handles this using a parent selector hack. I've tweaked it slightly for my own purposes...
#mixin message-error() {
$class: '.message-error';
#{$class} {
background-color: red;
}
p#{$class} {
background-color: yellow;
}
}
#include message-error();
wheresrhys uses a similar approach above, but with some sass errors. The code above allows you to manage it as one block and collapse it in your editor. Nesting the variable also makes it local so you can reuse $class for all instances where you need to apply this hack. See below for a working sample...
http://sassmeister.com/gist/318dce458a9eb3991b13
I use an #mixin function like this, when i need change some element in middle
of a sass big tree.
The first parameters is the parent element, the target, and the second the class that should have.
SASS
#mixin parentClass($parentTarget, $aditionalCLass) {
#at-root #{selector-replace(&, $parentTarget, $parentTarget + $aditionalCLass)} {
#content;
}
}
Sample,
like i need to improve font size in a strong tag, when .txt-target had .txt-strong too
HTML
<section class="sample">
<h1 class="txt-target txt-bold">Sample<strong>Bold</strong>Text</h1>
</section>
SASS
section{
.txt-target{
strong{
#include parentClass('.txt-target','.txt-bold'){
font-weight:bold;
font-size:30px;
}
}
}
}
Font:
https://sass-lang.com/documentation/at-rules/at-root
Here you can see a function called #mixin unify-parent($child) that looks like this
This cheat might work
{
$and: .message-error;
#{$and} {
background-color: red;
}
p#{$and} {
background-color: yellow
}
}
You may even be able to use $& as your variable name but I'm not 100% sure it won't throw an error.
And SASS has inbuilt scoping, which removes having to worry about the value of $and leaking out to the rest of your stylesheet
Variables are only available within the level of nested selectors
where they’re defined. If they’re defined outside of any nested
selectors, they’re available everywhere.
In the Current Release: Selective Steve (3.4.14) this is now possible, just need to update a little bit your code:
.message-error {
background-color: red;
p &{
background-color: yellow
}
}
this only works if you are one level nested, for instance it does not work if you have something like this:
.messages{
.message-error {
background-color: red;
p &{
background-color: yellow
}
}
}

Resources