How to override mixin in Less - css

I want to override a property of the .btn mixin. I tried following code.
.btn() {
text-align: center;
}
.btn() {
text-align:left;
}
.button{
.btn;
}
Less generates following code according to above snippet.
.button {
text-align: center;
text-align: left;
}
Of course I can try to use "!important" tag, but I don't want this. I am expecting following output.
.button {
text-align: left;
}
How can I do it?

Related

SASS mixin : how to add class before?

I'm struggling with creating a mixin with sass and I can't seem to find a solution. If anyone has any ideas...
I have something like this:
.tata {
font-size: 12px;
.toto{
display: block;
.tutu {
text-align: left;
#include mixin_test{
background: red;
}
}
}
}
and I'd like to have something like this when compiled:
html .tata .toto .tutu {background:red}
I've tried this, but the result is not what I expected:
#mixin mixin_test {
html{
#content;
}
}
Does anyone have a solution?
You need to edit your mixin. Missing & after the selector:
#mixin mixin_test {
html & {
#content;
}
}
.tata {
font-size: 12px;
.toto{
display: block;
.tutu {
text-align: left;
#include mixin_test{
background: red;
}
}
}
}
On this page you can read more about parent selector: Parent Selector

Merging selector #extend issue

I have a problem about "#extend" directive in SCSS.
.header {
.introduction-group {
text-align: center;
color: $white;
width: 70%;
}
.about {
&__description-group {
#extend .introduction-group;
This code block does not work. However,
.header {
&__introduction-group {
text-align: center;
color: $white;
width: 70%;
}
.about {
&__description-group {
#extend .header__introduction-group;
Second one works. Why?
Thank you.
As mentioned here nested classes won't be applied with #extend. Your second code block targets the specified class including the parent prefix. The first code block doesn't, it only targets the nested class.
I made a small codepen demo to illustrate the problem in a simple way. Make sure you checkout the Sass docs for a more comprehensive explanation!
<h1 class="wrong">Test style gone wrong</h1>
<h1 class="right">Test style gone right</h1>
.test {
.nested {
color: red;
}
&-nested {
color: red;
}
}
.wrong {
#extend .test;
#extend .nested;
}
.right {
#extend .test-nested;
}

SASS Ampersand – Chaining CSS class with the parent selector '&' like in LESS

LESS (CSS)
see in action
.app {
#page {
.inner {
.left {
&.padding-left-10px {
padding-left: 10px;
// rtl direction
.rtl& { //////////////////////////////////
padding-left: 0;
padding-right: 10px;
}
}
}
}
}
}
Consider the line I have highlighted with ///.....
I want the same result in SASS (.scss). Is it possible?
Expected result should be:
.rtl.app #page .inner .left.padding-left-10px {}
and not
.rtl .app #page .inner .left.padding-left-10px {}
Thanks.
It looks like you are attempting to use the LESS feature where you can change the order of the selectors by using the parent selector. It isn't working as expected because that specific LESS feature isn't implemented the same way in SASS.
If you want the equivalent output code in SASS, then you can use the #at-root directive in order to scope the selector to the root. Then you would also need to use variable interpolation (i.e., .rtl#{&}) for the parent selector:
.app {
#page {
.inner {
.left {
&.padding-left-10px {
padding-left: 10px;
#at-root {
.rtl#{&} {
padding-left: 0;
padding-right: 10px;
}
}
}
}
}
}
}
Which would compile to:
.app #page .inner .left.padding-left-10px {
padding-left: 10px;
}
.rtl.app #page .inner .left.padding-left-10px {
padding-left: 0;
padding-right: 10px;
}
Josh gave you an answer which will work, i guess. But I still wanna give you some advice and that is look into BEM, or someway. Nesting like this is really unnecessary.
Your code could be better for readability.
For example:
.padding {
padding: 10px;
}
.padding--left { // This is a modifier for padding
padding: 0 0 0 10px;
}
.padding--right { // This is a modifier for padding
padding: 0 10px 0 0;
}
<div class="padding padding--left">Using it in a div</div>
You don't have to follow all the rules which are defined in BEM, but some are really nice to use.

In LESS, is it possible to import one selector's content into another one?

My goal is to import the content: '\e826'; from an icon class into another selector in case that content property changes in the future.
.icon-hi:before {content: '\e826';}
.panel {
background: white;
.panel-title {
&:before {
#include .icon-hi;
text-align: center;
width: 20px;
height: 20px;
}
}
}
Of course #import doesn't work for that, but is there another way?
For the purpose of defining a value in one place, you should use variables:
#icon-hi: '\e826';
.icon-hi:before {content: #icon-hi;}
.panel {
background: white;
.panel-title {
&:before {
content: #icon-hi;
text-align: center;
width: 20px;
height: 20px;
}
}
}
You can actually 'import one selector into another'. This is basically what mixins do. These are the first two features in the less documentation - http://lesscss.org/features/
A third option is to use the extend feature: http://lesscss.org/features/#extend-feature
You can, here's the example:
.icon-hi{
&:before{
content: '\e826';
}
}
.panel {
background: white;
.panel-title {
.icon-hi;
&:before {
text-align: center;
width: 20px;
height: 20px;
}
}
}
You have to define .icon-hi class and define before with nesting so the preproccessor can know what to fetch.

SASS, when to extend?

I'm currently working on a team that uses SASS. I see that we are extending styles that are very simple and to me I don't see the benefit of doing this. Am I missing something?
Here are some examples of a _Common.scss that is imported and used throughout other sass files:
.visibility-hidden{visibility: hidden;}
.display-inline { display: inline; }
.display-inline-block { display: inline-block; }
.display-block { display: block; }
.display-none { display: none; }
.display-box { display: box; }
.float-left { float: left; }
.float-right { float: right; }
.clear-both { clear: both; }
.width-percent-100 { width: 100%; }
.width-percent-65 { width: 65%; }
.width-percent-50 { width: 50%; }
.width-percent-45 { width: 45%; }
.width-percent-40 { width: 40%; }
.width-percent-33 { width: 33%; }
.width-percent-30 { width: 30%; }
.width-percent-20 { width: 20%; }
.height-percent-100 { height: 100%; }
.cursor-pointer { cursor: pointer; }
.underline { text-decoration: underline; }
.text-decoration-none { text-decoration: none; }
.bold { font-weight: bold; }
.font-weight-normal { font-weight: normal; }
.text-align-center { text-align: center; }
.text-align-left { text-align: left; }
.text-align-right { text-align: right; }
.font-10 { font-size: 10px; }
.font-11 { font-size: 11px; }
.font-12 { font-size: 12px; }
.font-13 { font-size: 13px; }
.font-14 { font-size: 14px; }
.font-15 { font-size: 15px; }
.font-16 { font-size: 16px; }
.font-17 { font-size: 17px; }
.font-18 { font-size: 18px; }
.font-percent-65 { font-size: 65%; }
.font-percent-80 { font-size: 80%; }
.font-percent-90 { font-size: 90%; }
.font-percent-100 { font-size: 100%; }
.font-percent-110 { font-size: 110%; }
.font-percent-120 { font-size: 120%; }
.font-percent-130 { font-size: 130%; }
.font-percent-140 { font-size: 140%; }
.font-percent-150 { font-size: 150%; }
.font-percent-160 { font-size: 160%; }
.font-percent-170 { font-size: 170%; }
.font-percent-180 { font-size: 180%; }
Example:
#CategoriesContainer
{
ul{
li{
&:first-child{
#extend .font-11;
}
a
{
#extend .font-11;
#extend .text-decoration-none;
}
}
}
}
You should only use extend when you have a certain attribute set that will be used multiple times. The sheer stupidy of extending a class with a class with one attribute that has the unit value worked into the name of it is incomprehensible.
A better example for a reason to extend can be found in the reference guide
Say we have 2 classes
.error {
border: 1px #f00;
background-color: #fdd;
}
.seriousError {
border-width: 3px;
}
.error is a general no interesting style but a serious error should be really clear.
.seriousError is created to thicken the line, the only problem is that now we have to use both classes in the html to combine the styles.
Because we're lazy and just want to use one class and not duplicate code that might be changed in the future we can extend .seriousError with .error
.seriousError {
#extend .error;
border-width: 3px;
}
Now we didn't duplicate the code in our sass file but did get the right styles on the page.
Check out the reference guide for more/better examples.
Just please for the sake of kittens stop extending classes with one attribute classes. And don't implicitly state the value/attributes in the selector, thats not very semantic.
You, and your team, should read this post which explains a few problems with the aproach you take here vs semantic code. Couldn't find a better tuned post this quick.
You aren't missing anything, this is just bloated code in poor form and not a great way to extend classes.
There is maybe one (bad) reason I can imagine why this would be used. If for example .font-10 needs to be .7em instead of 10px, it can be easily changed - but then you've just defeated the point of naming the class "font10". Something like small-font would even make more sense in that case (and I'm not suggesting you use that either).
I won't discuss the merits of semantic class names and the folly of presentational ones (especially as literal as these are), but I will suggest that this is a very narrow use of extending classes. With a 1:1 mapping of class name to property/value, you've practically defeated the purpose of #extend, which is supposed to make you write less CSS.
Better example of what to use #extend for:
.media {
padding:1em;
border-color:blue;
background-color:red;
clear:left;
}
.my-media {
#extend .media;
background-color:green;
}
Atomic CSS
The technique of very simple CSS rules does have a bit of precedent - at Yahoo! they call it Atomic CSS. Thierry Koblentz argues in this Smashing Magazine article for using the simple classes directly in your markup, similar to inline styling. This can be helpful on very large projects across multiple web properties, where styles are not consistent. Base styles for OOCSS components can't be reused as much in such a situation, causing you to have to write many more lines of extension classes or overrides.
The downside is, of course, as Wesley mentioned, that it is much more difficult to make changes across your entire project's styles, such as updating the text size of a specific selector.
I've been playing around with a variant of this technique recently in a fairly large project, where styles can often be one-off. In an effort to avoid the I try to avoid putting hard values directly in the selectors. For instance, the following css (example fiddle):
_colors.scss
.text-white {
color: $white;
}
.blue {
#extend .text-white;
background: $blue;
}
_effects.scss
.circle {
width: 50px;
height: 50px;
border-radius: 50%;
text-align: center;
line-height: 50px;
font-size: 40px;
}
.matted {
border: 4px solid $white;
}
.shadow {
#include box-shadow(0 1px 4px 1px rgba($black, 0.25));
}
HTML:
<div class="blue matted circle shadow">?</div>
Specificity issues
One last thing to keep in mind if you decide to use this technique - it can cause specificity problems if you're extending base-level classes that use the same CSS properties. For instance, in the following example (fiddle), how would your border-radius appear? You wanted the top to be squared off (no border-radius) but this isn't happening, because the .circle class is further down in your css and just as specific (single class) as the other effects. This is a bit of a contrived example, but if you reuse CSS properties across your atomic selectors, this can be a real problem.
_colors.scss
.text-white {
color: white;
}
.blue {
#extend .text-white;
background: royalblue;
}
_effects.scss
.squared-top {
border-top-left-radius: 0;
border-top-right-radius: 0;
}
.rounded {
border-radius: 10px;
}
.circle {
width: 50px;
height: 50px;
border-radius: 50%;
}
HTML:
<span class="circle blue rounded squared-top"></span>
If you do it that way you can also use it directly in the HTML - so it looks like they took the OOCSS path and because it's already in the CSS you can now also extend to it. Very flexible but it could also turn very messy.
Extend option is used poorly here. It should be used for extending classes with more content and in that case extend can be very helpful.You can find more about extend and its options here.

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