Assuming that I have the following HTML:
<div class="navigation__item">
<span class="navigation__item__icon"></span>
</div>
I want to apply some rules to an icon, when hovering an item, which can be described with the following CSS:
.navigation__item__icon {
color: black;
}
.navigation__item:hover .navigation__item__icon {
color: white;
}
I can achieve this using the following SCSS:
.navigation__item {
&:hover {
.navigation__item__icon { <-- here
color: white;
}
}
&__icon {
color: black;
}
}
Here, is there any way to avoid writing navigation__item? Something like "parent rule \ element".
I like Sass for logical structure so that if I want to rename the whole navigation block with elements, I can simply change navigation class name in the root, and everything is renamed. This case breaks this advantage.
Update: Actually, I have found a way to do this without using {} braces. & can be repeated more than once:
.navigation__item {
&:hover &__icon {
color: white;
}
&__icon {
color: black;
}
}
It is great, but it doesn't make much sense if I have many rules and rules for &:hover itself. The question is still open - is this possible to access sibling element definition from within the {} block.
In Stylus there is a Partial reference but I don't know anything similar in SASS. One solution could be using a variable for the parent selector:
.navigation__item {
$selector: &;
&:hover {
#{$selector}__icon {
color: white;
}
}
&__icon {
color: black;
}
}
Is usefull is you change navigation__item class for another.
EDIT: I had used a wrong example, it's OK now.
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;
}
}
}
I want to add scope to my selectors.
A good way to achieve it in my opinion is to select css selector and return mySelector + oldSelector
For example I have .old { background: black; }, I would transform it into .mySelector .old { background: black; }
Let's say I have this CSS
.a
{
background: red;
}
#b {
background: green;
}
input {
background: blue;
}
[type=custom] {
background: white;
}
I would do .+?{, but it selects not needed parts. Inverse of {.+?} would work, but I don't know how to inverse it. Any ideas ?
I figured out I can use String.match({.+?}) to get all rules and String.split({.+?}) to get selectors in JavaScript.
Also I've found a library to easily parse CSS in JavaScript https://github.com/reworkcss/css
I have this simplified Less script
.placeholder(#color: #333333) {
&::-webkit-input-placeholder { color: #color; }
}
input {
.placeholder();
}
.placeholder {
margin-top: 20px;
}
The output when I run this through my local compiler or winless online less compiler is
input {
margin-top: 20px;
}
input::-webkit-input-placeholder {
color: #333333;
}
.placeholder {
margin-top: 20px;
}
Insted of the desired output
input::-webkit-input-placeholder {
color: #333333;
}
.placeholder {
margin-top: 20px;
}
Is this a bug or am I missing something here?
By the result it looks to me like I can't have CSS-selectors with the same name as mixins with default values.
I'm running into this problem when compiling Bootstrap with my site specific code. In this particular case I can work around it, but as the project grows and I include other projects I can't imaging I have to keep track of any mixins with default values?
Edit: I see now that I should have read the manual and pretty much seen on the first page of the docs that everything can be treated as a mixin.
In Less, everything is technically a mixin irrespective of whether we write it with parantheses (as in with parameters) or without parantheses (as in like a CSS class selector). The only difference between the two is that when the parantheses are present, the properties present within it are not output unless called from within a selector block.
Quoting the Less Website:
It is legal to define multiple mixins with the same name and number of parameters. Less will use properties of all that can apply.
In this case, since the other mixin has a default value for its only parameter, both the properties can apply when called without any parameter and hence there is no way to avoid it from happening.
Workaround Solution: One possible solution to work-around this problem is to enclose all such conflicting rules within a parent selector (like body).
.placeholder(#color: #333333) {
&::-webkit-input-placeholder { color: #color; }
}
input {
.placeholder();
}
body{
.placeholder{
margin-top: 20px;
}
}
Compiled CSS:
input::-webkit-input-placeholder {
color: #333333;
}
body .placeholder {
margin-top: 20px;
}
Option 2: Extracted from the solution posted by seven-phases-max in the Less GitHub Issue thread.
For the particular use-case one of possible workarounds is to isolate conflicting classes in unnamed scope so they won't interfere with external names:
.placeholder(#color: #333333) {
&::-webkit-input-placeholder { color: #color; }
}
input {
.placeholder();
}
& { // unnamed namespace
.placeholder {
background: #ffffff;
}
} // ~ end of unnamed namespace
Note: The above is a straight copy/paste from the GitHub thread without any modifications so as to not tamper with the information.
#mixin placeholder(#color: #333333) {
&::-webkit-input-placeholder { color: #color; }
}
input {
#include placeholder();
}
.placeholder {
margin-top: 20px;
}
that should work.
So if i understood right, you just want to add 20px on top of the placeholder ? Add padding-top to input instead.
input {
padding-top: 20px;
}
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
}
}
}