I have a class in my css called .btn:
.btn {
//stuff here
}
and I am going to create another class, lets say .btn2. I want to be able to inherit the characteristics from .btn into btn2, as I only want to change the color of button 2. Is there a way in CSS for this? Or should I just copy and paste the original stuff into the new class?
I'd suggest:
/* comma-separated selectors: */
.btn,
.btn2 {
/* shared properties */
}
.btn2 {
/* properties unique to btn2 */
}
JS Fiddle demo.
You can do it with dynamic stylesheets. Check out LESS or SASS.
EDIT:
Some additional info at a commenter's request. Here are the official sites. They both have examples on their home pages.
http://lesscss.org/
http://sass-lang.com/
What you can do is this
.btn, .btn2 {
/* Styles goes here */
}
This way, both the classes will share common properties defined in the rule block.
As far as the inheritance goes, something you would like to have..
.btn2 {
.btn; /* Won't work in pure CSS */
}
Won't work in pure CSS, you need to take a look at SASS or LESS
Related
I'm looking into LESS because I definitely see some of their benefits. For instance colour declaration.
One thing I don't understand tho, and maybe I'm not getting the flow right is - why use the following LESS snippet
.radius {
-webkit-border-radius:5px;
-moz-border-radius:5px;
border-radius:5px;
}
.btn-red{
background-color:red;
.radius;
}
.btn-green{
background-color:green;
.radius;
}
...
When we can use the .radius class in the html file right away. I'm left with the impression that LESS will add a ton of duplicate code once it gets compiled.
I'm using the following, which makes more sense. Same with font-size, margins, etc... Aren't classes used in such cases?
<div class="btn-red radius">Cancel</div>
<div class="btn-green radius">Go</div>
The snippet above does not benefit from SASS/LESS capabilities that much. Lets have a closer look and check this SCSS snippet.
// Abstract placeholder.
%radius {
border-radius: 5px;
}
// Put your global styling here.
// I'm assuming that you can alter the markup and have button.btn.btn-green
.btn {
// Color modifier.
&-red {
#extend %radius;
background-color: red;
}
&-green {
#extend %radius;
background-color: green;
}
}
The CSS output will be:
.btn-red, .btn-green {
border-radius: 5px;
}
.btn-red {
background-color: red;
}
.btn-green {
background-color: green;
}
And then you have to pick up Autoprefixer and vendor-prefixes issue is solved once and for all.
Because now, you can just specify the class btn_red or btn_green and all the buttons will automatically have a radius.
Your HTML should contain only the semantics, and styling or classes referring to styling should not be part of it.
That applies to the other classes as well. If for instance, you would rename btn_red to btn_cancel, you have a meaningful classname that you can apply to any kind of cancel button. And in the CSS you can specify that a cancel button is red and a 'Go' button is green, and both have a radius, without needing to modify the HTML at all.
So, the ultimate goal is to have the HTML describe the structure and the CSS describe how that structure should look. And a CSS preprocessor is only their to make a bulky spaghetti-like CSS file more structured.
There are several benefits.
You can use more semantic class names. Rather than encoding style information directly in your class names, (btn-red, radius) you could use a single class that conveys the usage of the style, rather than its contents.
You can avoid repeating yourself.
#radius-size: 5px;
-webkit-border-radius:#radius-size;
-moz-border-radius:#radius-size;
border-radius:#radius-size;
You can parameterize it so that you'd be able to use different radiuses (radii?) in different contexts.
.radius(#radius-size) { ... }
Because there are cases that developer has-no-access or don't-want to change the markup. and the only solution is to include all props from a predefined class.
for example:
you have bootstrap loaded (then you already have .has-success and .has-error classes) and if you want to use HTML5's native form validation using input's :valid and :invalid states, you have to use JavaScript to add/remove success/error classes based on input's states. but with this feature of LESS you can include all props of success/error class inside input's states. the code for this example could be something like this:
#myinput {
&:valid { .has-success; }
&:invalid { .has-error; }
}
I have tried to combine to classes in CSS, but I end up failing. I used this code:
.container{
.ningbar
}
What I would like to do is combine the items in the ningbar layer with the items in the container layer. Thanks, Phineas.
This would do the job:
.container { /*container rules*/ }
.ningbar { /*ningbar rules*/ }
.container,.ningbar { /*shared rules*/ }
.container, .ningbar { }
Use the same rules for both.
why do you want to combine two classes ? I would make two seperate classes and use them in my controls as below
CSS:
.class1{
/* All styles for class1*/
}
.class2{
/* All styles for class2*/
}
HTML:
<div class="class1 class2"></div>
This way you can add both classes to your controls/DOM elements keeping them seperate in your CSS.
In order to use another styles' for another class, there is LESS, if I can say.
In a nutshell, LESS will help you to maintain more easily, and comprehensible your styles' files. You will be able to add variables, to avoid repetitions of same colors' codes, for instance.
You can view more detail on LESS's website : http://lesscss.org/
But, it's probably a complicated way, to simply add properties from another class.
For Combining two class you can us
.Class1 .Class2 {
//All style for combination of these two classes
}
I have a very wierd question, I dont know wether if its possible in css or not
Suppose I have say 3 different css classes as shown below, as you can see I have a common property of all these classes, I want to declare this color somewhere else and pass a reference to it here, so if next time I want to change the color I can simply change at one place rather than changing in all the 5 classes.
I know that you can use body{}, or a wrapper for this but that would affect the colors of the entire site right ? Is there a way to do this ?
Is this even possible ?
.abc {
color:red;
}
.abc2 {
color:red;
}
.abc3 {
color:red;
}
.abc4 {
color:red;
}
.abc5 {
color:red;
}
The bad news: you can't do it in CSS.
The good news: you can write in a meta-CSS language like LESS, which then processes a LESS file to pure CSS. This is called a "mixin".
In LESS:
#errorColor: red;
.error-color {
color: #errorColor;
}
#error-1 {
.error-color;
}
.all-errors {
.error-color;
}
More info: http://lesscss.org/#-mixins
if you want to declare all of them at a time, you can use:
.abc, .abc2, .abc3, .abc4, .abc5 {
color:red;
}
Or you can declare an additional class & add to all the .abc, .abc2.... & make its color:red;.
This can not be done with CSS, but that is still a very popular thing to do by using a CSS preprocessor such as LESS, SASS, SCSS, or Stylus.
A preprocessor will let you define a variable (say $red = #F00). It will replace the variable in your CSS document with the variable value for you, allowing you to write very DRY and module CSS.
This functionality is referred to as "CSS variables", which is part of the future spec, but not yet implemented on any browsers.
For now, the best way to do this in pure CSS is to declare an additional class for the desired "global", and then add that class to all relevant items.
.abc_global { color: red; }
.abc1 { /* additional styling */ }
.abc2 { /* additional styling */ }
<div class="abc1 abc_global"></div>
<div class="abc2 abc_global"></div>
With LESS
You are able to define that red color once:
.myRedColor {
color:red;
}
Now you can call that red on any CSS styles. Even NESTED styles! It's a wicked tool!
.abc1 {
.myRedColor;
}
.abc2 {
.myRedColor;
}
.abc3 {
.myRedColor;
}
.abc4 {
.myRedColor;
}
NESTED EXAMPLE:
.abc {
.itsEasyAsOneTwoThree{
.myRedColor;
}
}
Now all of our "itsEasyAsOneTwoThree" classes that are properly nested inside of an "abc" class will be assigned the red style. No more remembering those long #867530 color codes :) How cool is that?!
You can also use PostCSS with the plugin postcss-preset-env and support custom properties/variables, then use the :root selector to add global css variables.
:root {
--color-gray: #333333;
--color-white: #ffffff;
--color-black: #000000;
}
I have a webpage that is generated by Drupal and it comes with a certain stylesheet attached to it.
I would like to override one of the styles. It is set with a class like this:
<div class="description"></div>
So instead of using the ".description" style that comes with the Drupal CSS, I would like the page to use my ".description" style. In other words - if the page has 2 ".description" styles, how do I tell the page to use mine?
Use a selector with higher specificity:
div.description {
/* will take precedence over just .description */
}
Place your stylesheet after the one you want to override:
/* Drupal's style */
.description {
foo: bar;
}
/* Your style */
.description {
foo: baz; /* takes precedence over foo: bar */
}
Do not use !important. Just don't.
See also CSS 3: Calculating Selector Specificity.
I'm trying to select input elements of all types except radio and checkbox.
Many people have shown that you can put multiple arguments in :not, but using type doesn't seem to work anyway I try it.
form input:not([type="radio"], [type="checkbox"]) {
/* css here */
}
Any ideas?
Why :not just use two :not:
input:not([type="radio"]):not([type="checkbox"])
Yes, it is intentional
If you're using SASS in your project, I've built this mixin to make it work the way we all want it to:
#mixin not($ignorList...) {
//if only a single value given
#if (length($ignorList) == 1){
//it is probably a list variable so set ignore list to the variable
$ignorList: nth($ignorList,1);
}
//set up an empty $notOutput variable
$notOutput: '';
//for each item in the list
#each $not in $ignorList {
//generate a :not([ignored_item]) segment for each item in the ignore list and put them back to back
$notOutput: $notOutput + ':not(#{$not})';
}
//output the full :not() rule including all ignored items
&#{$notOutput} {
#content;
}
}
it can be used in 2 ways:
Option 1: list the ignored items inline
input {
/*non-ignored styling goes here*/
#include not('[type="radio"]','[type="checkbox"]'){
/*ignored styling goes here*/
}
}
Option 2: list the ignored items in a variable first
$ignoredItems:
'[type="radio"]',
'[type="checkbox"]'
;
input {
/*non-ignored styling goes here*/
#include not($ignoredItems){
/*ignored styling goes here*/
}
}
Outputted CSS for either option
input {
/*non-ignored styling goes here*/
}
input:not([type="radio"]):not([type="checkbox"]) {
/*ignored styling goes here*/
}
Starting from CSS Selectors 4 using multiple arguments in the :not selector becomes possible (see here).
In CSS3, the :not selector only allows 1 selector as an argument. In level 4 selectors, it can take a selector list as an argument.
Example:
/* In this example, all p elements will be red, except for
the first child and the ones with the class special. */
p:not(:first-child, .special) {
color: red;
}
Unfortunately, browser support is somewhat new.
I was having some trouble with this, and the "X:not():not()" method wasn't working for me.
I ended up resorting to this strategy:
INPUT {
/* styles */
}
INPUT[type="radio"], INPUT[type="checkbox"] {
/* styles that reset previous styles */
}
It's not nearly as fun, but it worked for me when :not() was being pugnacious. It's not ideal, but it's solid.
If you install the "cssnext" Post CSS plugin, then you can safely start using the syntax that you want to use right now.
Using cssnext will turn this:
input:not([type="radio"], [type="checkbox"]) {
/* css here */
}
Into this:
input:not([type="radio"]):not([type="checkbox"]) {
/* css here */
}
https://cssnext.github.io/features/#not-pseudo-class