I've noticed that every view in my application has a style file starting like this.
:host {
display: flex;
background-color: blue;
}
div.foo {
background-color: red;
}
It seemed as a wise decision to reduce redundancy and move the general definition to styles.scss. Doing so, I noticed that, while the DIV styling continued to work as expected, the effect on the pseudo-selector vanished.
Googling gave me that I can't reach the host element from inside the component but it doesn't say anything about altering it from outside of it (which my global styles.scss certainly is). I also found a blog on Angular view encapsulation where details are discussed in depth, however, without mention of the global styles.scss.
Summarizing, I've found a lot of info on handling :host and a lot of info on applying global styles.scss. However, I've seen rather limited intersection between them. Such an absence of an explicit confirmation implies often that it's infeasible or at least higly discouraged.
Have I misunderstood the point made in the docs? If so, how can I control the :host speudo-class from my global styles.scss? Or is it a special case of no-no and can't be done?
EDIT
A simple solution using CSS only - :host>* { color: blue; } in your root component.
Note: This CSS rule will only design components at the first level, If you want to apply to all components of the app you will need to use the original answer
ORIGINAL
I was looking for an elegant way to get what you are asking for, And the best way I've been able to accomplish this is by using SASS.
I did an experiment and saw when inheriting a SASS file with a :host definition, the :host selector refers to the component that inherits it.
After a try, the steps below works the same with CSS;
the steps (SCSS / CSS tested):
add new folder under src named styling (or whatever you want), add inside new file name _base.scss (note the underscore)
inside _base.scss add the style for :host
in your components sass style, at first line add #import "~src/styling/base";
That's it!
There is a way to define your own import paths for SASS like node_modules libraries, all you need to do is make a stylePreprocessorOptions entry in the options section of the angular.json file. You do not need to include everything using src\sass
angular.json
"options": {
"outputPath": "dist/App",
"index": "src/index.html",
"main": "src/main.ts",
"polyfills": "src/polyfills.ts",
"tsConfig": "src/tsconfig.app.json",
"assets": [
"src/favicon.ico",
"src/assets"
],
"styles": [
"src/sass/styles.scss"
],
"stylePreprocessorOptions": {
"includePaths": [
"src/sass"
]
},
"scripts": []
},
Now in your component styles simply import styles.scss. Don't include the file extension or an initial ~
#import './styles.scss';
Related
Question
How can I globally import variables.scss 1. without importing them in every file and 2. by referencing instead of duplicating them in my build?
Setup
I use Vue2 and laravel-mix and I have index.scss imported in my main.js
variables.scss
$--test: #ff0000;
index.scss
#import 'variables';
.dashboard-title {
color: $--test;
}
This colors the title red. But when I try to do the same thing inside of the component, it doesnt work:
<style scoped lang="scss">
.dashboard-title {
color: $--test;
}
</style>
This doesn't work, but I proved that index.scss is global in my first example. How is
variables.scss not global, when I import it in my global index.scss?
I can fix the error by importing the variables file in the component, but by doing this, I essentially duplicate the whole variables.scss file every time I import it in a vue component.
I found this out by analyzing my bundle with a webpack bundle analyzer, this is the output:
webpack bundle analysis image (all blue crossed parts are increased in size because the variables file is imported, this isn't a big problem now, but this will exponentially increase my bundle size with time)
It would reduce my bundle size by atleast 20% right now...
How can I reference the variables.scss file instead of duplicating its content?
What I've tried:
https://css-tricks.com/how-to-import-a-sass-file-into-every-vue-component-in-an-app/ (I wasn't able to "migrate" this to a laravel-mix config)
I've also tried using purgeCss to remove duplicate css, this just completely messed up my styles but reduced the bundle size by 50% lol
Adding this to the webpack.mix.js
mix.webpackConfig({
module: {
rules: [
{
test: /\.scss$/,
use: [
{
loader: 'sass-loader',
options: {
//this might be "data" or "prependData" depening on your version
additionalData: `#import "./resources/js/styles/variables.scss";`
}
}
]
}
]
}
})
This does make the variables global, but imports(duplicates) them for every vue component, even if they aren't being used.
Edit: This only is an issue, when the imported file is relatively big. In my project, the imported file itsself imported a theme scss (to get access to the themes variables), which ultimately copied this whole thing everywhere I needed the variables.
I fixed this by defining my custom variables in a seperate file and using those variables in the "overwriting-variables" file, something like this:
custom-variables.scss
$red: #ff0000;
overwriting-variables.scss
import 'theme.scss'; //this bloated my project
import 'custom-variables';
$--theme-red: $red
And when I needed this theme color in my vue components I just imported the custom-variables.scss instead of overwriting-variables.scss.
This does fix my bloating issue, but doesn't fully solve the problem, I still have multiple instances of the custom-variables.scss in my project, it just doesn't matter (yet) because its really small. So I'd be still happy to hear about other solutions!
If you import every .scss in your index.scss, then every variable should work. Try this in your vue.config
css: {
loaderOptions: {
// by default the `sass` option will apply to both syntaxes
// because `scss` syntax is also processed by sass-loader underlyingly
// but when configuring the `data` option
// `scss` syntax requires an semicolon at the end of a statement, while `sass` syntax requires none
// in that case, we can target the `scss` syntax separately using the `scss` option
scss: {
prependData: `#import "#/style/index.scss"`
}
}
},
So I got it working with laravel-mix like this:
mix.webpackConfig({
module: {
rules: [
{
test: /\.scss$/,
use: [
{
loader: 'sass-loader',
options: {
//this might be "data" or "prependData" depening on your version
additionalData: `#import "./resources/js/styles/variables.scss";`
}
}
]
}
]
}
})
Not sure yet if this prevents the duplication though
Edit: It does not prevent duplication, it does increase the bundle size in every vue component. So I now have a 150% bigger bundle, because the variables file is imported in every single vue component. Even if the variable isn't even used.
I am writing a Chrome extension to modify the CSS of a specific page. Although, when I try to apply styles using style.min.css my spreadsheet is rendered before the site's spreadsheet in the cascade. To be precise, my rules are computed before theirs so their rules override mine.
For example, if I try this
article {
background-color: red;
}
their rule gets computed last and my background won't be red.
This is what the dev tools look like. We can see my injected stylesheet doesn't have priority in the cascade.
Also this is my manifest.json without the project description and name.
"content_scripts": [{
"css": ["style.min.css"],
"js": ["main.js"],
"matches": ["https://intra.epitech.eu/*"]
}],
"permissions": ["tabs"]
So if anyone has any idea on how to go around that by prioritising your styles in a chrome extension please leave a comment :)
article {
background-color: red !important;
}
The !important tag stops other styles from overriding your styles.
You should use the !important tag lightly though. Because if you over use it you will start running into conflicting styles when your CSS file becomes very big.
As per the OP comments "run_at": "document_end" works only for js files.
So load js file at document end then insert css files dynamically by loading css files from that js file.
In manifest.json write this
"content_scripts": [
{
"js": ["main.js"],
"matches": ["https://intra.epitech.eu/*"],
"run_at": "document_end"
}
]
More specific rules override more general ones (https://www.w3.org/TR/2011/REC-CSS2-20110607/cascade.html#cascade) :
#homeboard section article {
background-color: red;
}
In my Nuxt app I load all my SASS thus:
css: [
'~assets/scss/main.scss'
],
It works perfectly, except when I'm trying to use some SASS variable from within a component.
<style lang="scss">
.container {
background-color: $white;
}
</style>
In this case I get this error message:
SassError: Undefinied variable: $white
Yet, all of the SCSS contained in the SASS file where the variable is defined works throughout the app.
It is as if the app as a whole knew these files, but each individual component doesn't.
What's going on?
Most of the other answers don't take into account that Nuxt.js hides all the Webpack setup and forces you to do everything through nuxt.config.js.
My guess is that Webpack isn't compiling all the SCSS declarations together and therefore can't find the variable.
It's been a few months since I had this issue so things may have changed but here goes...
Make sure you have the correct Node packages installed (Nuxt DID NOT do this by default for me) npm i -D node-sass sass-loader
Add your CSS & SCSS files to the css: [] section of nuxt.config.js Order matters here so make sure things like variables are added before things that use them if you have separate files.
If you're using layouts (I think that's the default Nuxt setup) make sure that layouts/default.vue has a <style lang="sass"></style> block in it. If I remember correctly this can be empty but had to exist. I only have one layout but it may need to exist in all of them.
If all that seems like too much of a pain, there's a Nuxt Plugin that takes most of the work/management out of that process. Nuxt Style Resources Module
The confusing part is that:
styles from scss files CAN be loaded like this
//nuxt.config.js
css: [
'~assets/scss/main.scss'
],
//global scss file
$varcolor: black
h1{background: $varcolor}
BUT
the variables inside CAN NOT be used inside a component
//inside component
.component {background: $varcolor} // DOES NOT WORK
I also suggest the use of the nuxt style resource module:
https://github.com/nuxt-community/style-resources-module
new founded solution, checked and it's work. Founded here
add #nuxtjs/style-resources
export default {
css: [
'vendor.min.css'
],
modules: [
'#nuxtjs/style-resources'
],
//You will have to add this new object if it doesn't exist already
styleResources: {
scss: ['./assets/scss/main.scss'] // here I use only main scss with globally styles (variables, base etc)
},
}
it's strange, but if u change tilda (~) to dot(.), it's help for someone
from css: [ '~assets/scss/main.scss' ] to css: [ './assets/scss/main.scss' ]
this solution finded here
Us should either load the scss in your component
<style lang="sass">
#import 'path/to/your/_variable.scss'; // Using this should get you the variables
.my-color {
color: $primary-color;
}
Or adding the following to you to your vue.config.js
module.exports = {
css: {
loaderOptions: {
sass: {
data: `#import "#/pathto/variables.scss";`
}
}
}
};
Ref:
SassError: Undefinied variable: $white
Each <style lang="scss"> is compiled individually. You need to #import the file which defines $white into your component before the parser knows what $white means.
This is why most frameworks keep their variables in a _variables.scss file which is imported in all the other SCSS files/contexts.
The _variables.scss is not even loaded in the page, because in most cases it doesn't actually contain any rules. It only contains variable definitions which are imported into other .scss files, which output .css.
Ref:
Yet, all of the SCSS contained in the SASS file where the variable is defined works throughout the app.
If you import an SCSS file in your vue.config.js the output will be an ordinary <style> tag. Its contents will be generated at compile/build time and will result into some CSS (which apply to the entire document).
Unless specifically imported into the component SCSS, (using an #import command), the compiler will not know what $white means.
There is an important distinction to make between compilation context and browser context. Compilation happens at compile time (most likely in node-sass). Browser context is the actual browser, which only understands the CSS resulted from compilation.
How does Vue only apply style rules to the parent and not to the children with the same class? That's achieved by scoping.
It means applying a custom data-v-{key} attribute to all selectors in the generated <style> tag and to all elements the style should apply to.
See this example and inspect it using your web console: https://codesandbox.io/s/vue-template-ge2hb
It produces this markup:
As you can see, the scoped CSS has an extra [data-v-763db97b] added to the selector, which means it only applies to elements having that data attribute.
I do already have SCSS variables defined in src/styles/settings/_variables.scss and I am importing them into src/styles.scss, but still these variables aren't available for every single component.
Is there any way to make a global file which holds all SCSS variables for the rest of my components? Because writing #import in every single component .scss file it is very frustrating, especially if I have many nested components.
I know, there is a lot of similar questions, but it seems like they're all outdated and do not relate to the recent versions of Angular.
I use Angular 7.3 with CLI.
You just need to add a little more config, so where you are declaring your global variables, you need to wrap it up in :root{}. So in src/styles/settings/_variables.scss.
:root
{
--blue: #00b; // or any global you wish to share with components
}
Then when you use them in the SCSS you will need to access them like so.
.example-class {
background-color: var(--blue)
}
To add to this regarding comments, this method can use mixins, #media and keyframes and is not limited to just colours / font. That was an example.
From my understanding you need a global file src/assets/style/global and then to import each scss file into there where you are defining them like so.
#import 'filename';
If you dont want global variables to be used in within a component look when you have the globals working. Look into ViewEncapsulation, as this can be used to ignore them.
Is there any ways to make global file with scss variables available for all components?
Without importing global file everytime in each component, you want those sass variables been available, it's not possible.
The way it works in SASS, if using partials to better organize code, you can apply #import directive for referencing. So if there're some sass variables in shared/_variables.scss:
$lightslategray: #778899;
$darkgray: #A9A9A9;
and these variables need to be used in another stylesheet, stylesheet with them must be #import-ed into it firstly:
// Shared
#import "shared/variables";
.content {
background: $lightslategray;
}
In Angular it works in a similar way (related referencing external stylesheet). So if you need some sass variables, mixins or functions to be used by a particular component.scss, there is no other clean way, but to reference them in that component.scss using #import directive. To ease the task, you can create a file src/_variables.scss and use syntax like this in your component.scss:
#import “~variables.scss”;
step one : go to custom scss file (shared/css/_variable.scss) and write this part
:root{
--color-text: red;
--color-btn-success: green;
}
after go to style.scss (this is main file) and import this file :
#import './shared/css/Variables';
now you can use variables in all components with this Syntax:
.sample{
color : var(--color-text);
}
Easily possibe to access sass style(s) from a global file with two steps.
Add folder path of the style files to includePaths array in angular.json file.
Import style file by file-name in any component.
let say your files and folder structures is as follows: src > my-styles-folder > var.scss
angular.json
"architect": {
"build": {
...
"options": {
"stylePreprocessorOptions": {
"includePaths": [
"src/my-styles-folder" // add path only, do not include file name
]
},
"styles": [
...
]
}
...
}
}
some-component.scss
#import "var"; // var.scss
mat-toolbar {
height: $toolbar-height;
}
In angular 8 work for me.
In your _variable.scss file you have to add:
:root{--my-var:#fabada}
After that go in your angular.json and add this in "styles":
{"input":"yourPath/_variables.scss"}
I have edit the angular.json styleext for using less
"schematics": {
"#schematics/angular:component": {
"prefix": "app",
"styleext": "less"
},
"#schematics/angular:directive": {
"prefix": "app"
}
}
I create a component and test the less it works. But now i want to mix the component css/less with the bootgstrap classes.
For example I want all button in my component to have .mx-1
I type in my less:
.btnmx-1{
.btn();
.mx-1();
}
but it failed. I tried to import :
#import "../../../../node_modules/bootstrap/dist/css/bootstrap.min.css";
.btnmx-1{
.btn();
.mx-1();
}
this one also failed to compile with error : .btn is undefined
How to fix this ? I want all buttons in my component to have margin left and right 1px inherited from bootstrap
For Bootsrap:
npm install bootsrap --save
in angular.json:
"styles": [
"node_modules/bootstrap/dist/css/bootstrap.css",
"src/styles.scss"
],
For less:
add less file type instead css (by default)
comp.component.less
in angular.json.
Set the property defaults.styleExt to less.
Here's how I use bootstrap in my project
Download bootstrap Source files from link: https://getbootstrap.com/docs/4.0/getting-started/download/
create styles folders in your project copy scss folder from resource to it and rename it to bootstrap to more clearly
create your own mixin and import it bootstrap.scss file(below all of the existing imports)
import bootstrap.scss to style.scss(or in angular.json)
In my case, I just want to use bootstrap utils classes like padding, margin,heading...so I just keep these files in my boostrap scss folder
If you need all just keep all or remove some modules that need bootstrap js to run like carousel....