How do I override global styles in nextJS - css

I have some css rules in my global.css file, how do I override these stylings for specific pages?

NextJs comes bundled with styled-jsx. You can leverage this library to insert css rules in the page, which can override rules set by your global css file.
export default () => (
<div>
<style jsx global>{`
body {
background: red;
}
`}</style>
</div>
)

Simply create a class or id in the top level element of the page. After you‘ve done that, override the styles you want by specifying new styles with the selector of the page. By doing that, the styles will be more specific than the global css-rules, which will therefore be overriden.
See an example below.
// global.css
p {
font-size: 1.2rem;
}
// Style to load on the page that has a top level selector of #landing-page.
#landing-page p {
font-size: 2rem;
}
An other alternative would be to use a layout component that is defined per page level, and load the global styles in there, if needed. Checkout this link.

Related

Chain selectors for custom module styling in Next JS not working

Chaining selectors in css file doesn't seem to apply styles. I am importing the styles in the component and it only applies for the main class, for example:
import styles from './Home.module.css'
const Home = () => {
return (
<header className={styles.header}>
<div className={styles.headerContainer}>
...
and than in Home.module.css I have:
.header {
// some styles that are getting applied
}
.header .headerContainer {
//some styles that don't show up
}
On the page I am able to see header that is styled but not the headerContainer. So I understand that Next js automatically adds some variables to the end of the classes when passing styles item to jsx but trying to understand how I would chain the selectors in css and be able to use styles in such way in Next JS.

Vue - How to override all: unset for inner components

I'm injecting Vue app in to existing webpage which can be any page.
And I'm using this scss
#vueApp {
all: unset
* {
all: unset
}
}
on my Vue root element, to remove all parent styles from existing webpage to be applied in my Vue app.
But it also removes my styles I'm using in my own components.
I want my styles to be applied ON TOP of the applied all: unset style.
As I understand it happens because
#vauApp * {all: unset}
have higher priority than my components styles because it have deeper selector. And my component styles have only one selector for example
.myButton {...}
Current solution
Add additional selector to components styles
<style lang="scss" scoped>
#vueApp .myButton {
...
}

How to override css of other components from App

I need to make fonts for some of my components bigger when my app is in full screen mode. In my App.jsx I have variable that triggers me adding "fullscreen" class to the root DIV of the whole app. I can go brute force and override it like * { font-szie: 18px; } but thats too simple. I want to override certain classes only (like .some-class * { font-size: 18px; }). Of course React hash stands in my way so here is question: how do I apply my font size to all components in the app?
If you have hashed classes (i.e some-class-[hash]), you can use CSS selector to deal with it.
Like this:
[class^="some-class-"]
The above CSS selector will select all classes which start with "some-class-".
You can read more about CSS selectors here: https://www.w3schools.com/cssref/css_selectors.asp
You can use General Classes like Bootstrap or Tailwind, then you should use it in your public folder and use linkcss`
<head>
<link rel="stylesheet" href="..." />
</ head>
.text-sm {
font-size: 1rem !important;
}
import hashed_classes from "./file.css";
const Component = () => {
return (
<div className={`${hashed_classes.class} text-sm`} />
)
}

Angular: How to add global CSS (e.g. to the body), but only for one specific page?

How can I add separate CSS for one page in Angular?
This is the CSS I need, as per How to remove the URL from the printing page?:
#media print{
#page{
margin:0;
}
body{
margin:30px;
}
}
But putting CSS into the component with ::ng-deep or ViewEncapsulation.None won't help here, because when navigating away from a page, the CSS of the page isn't deleted.
I've added a Stackblitz, which explains the problem clearly.
I've come up with a potential solution, but it doesn't work:
encapsulation: ViewEncapsulation.None
...
constructor(private renderer: Renderer2) {
this.renderer.addClass(document.body, 'special-print');
}
ngOnDestroy() {
this.renderer.removeClass(document.body, 'special-print');
}
....
....
....
#media print{
#page{
margin:0;
}
body.special-print{
margin:30px;
}
}
Why it doesn't work:
While it would help with <body> CSS, it won't help with #page CSS. Perhaps the question would be better summarized as "How to add global CSS, but remove it when we leave the page?".
Solved!
We print the <style> block directly into the component's HTML, and therefore when the component gets removed, our <style> block gets removed too. (Normally this wouldn't work, but thanks to DomSanitizer.bypassSecurityTrustHtml, Angular won't break our code when running optimizations.)
Here's a StackBlitz.
First, create a new component to handle the work:
component.ts: (This is all we need. We don't need an HTML or style.css file.)
//Inside your local component, place this HTML
//<app-local-css [style]="'body{background:green !important;}'"></app-local-css>
// OR
//<app-local-css [scriptURL]="'/path/to/file.css'"></app-local-css>
#Component({
selector: "app-local-css",
template: '<span style="display:none" [innerHTML]="this.safeString"></span>'
})
export class LocalCSSComponent implements OnInit {
constructor(protected sanitizer: DomSanitizer) {}
#Input() scriptURL?: string;
#Input() style?: string;
safeString: SafeHtml;
ngOnInit() {
if (this.scriptURL) {
let string = '<link rel="stylesheet" type="text/css" href="' + this.scriptURL + '">';
this.safeString = this.sanitizer.bypassSecurityTrustHtml(string);
} else if (this.style) {
let string = '<style type="text/css">' + this.style + "</style>";
this.safeString = this.sanitizer.bypassSecurityTrustHtml(string);
}
}
}
And then use it like this:
mySample.component.html:
<app-local-css [style]="'body{background:green !important;}'"></app-local-css>
// OR
<app-local-css [scriptURL]="'/path/to/file.css'"></app-local-css>
Angular is doing client-side rendering, which is bad news, because you do not have separate pages. You have several possible solutions though:
1. Separate page
You can create another page with or without Angular, which includes the CSS you need and load that page. In the most simplistic approach to achieve this, the other page would have a different URL. If having a different URL is not to your liking, then you could hide your page's content and show the other page inside an iframe. It would admittedly be a hacky solution, but it is a solution.
2. Client-side CSS rendering
Instead of just loading the CSS, you could have a component which would control global CSS rules, matched by your view's name. You would have a template value rendered to a property, like:
#media print{
#page{
margin:0;
}
body{
margin:30px;
}
}
And when you visit the page where this needs to be activated, you would simply initialize a property with a style HTML element that was generated based on the template and added to head. Once you leave the given view, your component would detect that event and would remove() that element. If you choose this solution, then it would be wise to make sure that you are supporting this on more general terms, so that if some new views will have their custom global CSS, then they would be easy to integrate into your project in the future.
3. body classes
You could add/remove some custom-print or whatever class to/from body whenever the style is to be changed. This way you could add the CSS exactly once to your HTML and change the rules accordingly, like:
body.custom-print {
margin: 30px;
}
This would be a neat solution, but the problem in your case is that you have a #page rule as well and I'm not sure how you could make that dependant on body classes or some other HTML attributes. I would conduct quite a few experiments about this if I were you.
4. Iframe staging
You could avoid having that CSS in your main page, but would have a hidden iframe where you would have the CSS and would just copy the content into the CSS and once that's loaded, print that.
Don't change the whole body from apple. Instead, there are a few changes to make.
In the app component, hold a boolean for whether or not you are on apple, and use ngClass for class defined in scss.
Track which route you are on in appComponent, and set isApple accordingly
Add a div around all your html, for container to take full size
Add global html, body setting height to 100% so you see color everywhere
Remove body overriding in apple
so,
appComponent.ts:
isApple: Boolean;
constructor(router: Router) {
router.events.subscribe(v => {
if (v instanceof NavigationEnd) {
this.isApple = v.url === "/apple";
}
});
}
appComponent.html:
<div [ngClass]="{'red':isApple}" class="container">
<p>
There are two components: Apple and Banana. Switching between them will show
the problem.
</p>
<router-outlet></router-outlet>
</div>
appComponent.scss
.red {
background-color: red;
}
.container {
height: 100%;
}
apple.component.scss (remove body)
/*Sample "global" CSS, that affects something outside the current component.*/
::ng-deep {
#media print {
#page {
margin: 0;
}
}
}
styles.scss (global)
html, body {
height: 100%;
}
You can see this altogether at this Stackblitz link
You can add different css files in the component (for instance, app-task.component.ts):
#Component({
selector: 'app-task',
templateUrl: './app-task.component.html',
styleUrls: ['./app-task.component.scss', './styles2.scss', './styles3.scss']
})
In this example, the style files are in the same folder that the component, but this is not the best option: you have to put the files in assets, for example. Also, be careful with the thread of the styles, since the first one you put will be put before the second (obviously).

Applying CSS stylesheet only to active component

I'm working on a ReactJS app that has a header at the top, a menu on the left, and the "frame" in the middle is where routes and their corresponding components are loaded. I want to be able to apply a CSS stylesheet to specific components only when they are loaded. I also don't want them applied all the time or to the top header or left menu.
My expectation was that adding import 'custom.css'; to a specific component would only apply the stylesheet's styles to that component and it's children when the route is active. Instead, it applies it to the entire page even when the route/component are not loaded.
I understand that an alternative approach is styled components, but, for my use-case, a design company is supplying a stylesheet (which should remain unchanged) that we need to consume only for the sub-module I'm working on and I don't want its styles to affect the rest of the app.
How can I have a stylesheet only applied to my active route/component?
Use simple CSS technique. Suppose you have two components with different css files (say about.css and contact.css). Now consider your both CSS file have one common class with different style properties, like:
about.css
.container{
max-width: 400px;
}
contact.css
.container{
max-width: 500px;
}
Yes in ReactJS both the CSS files will load at the same time and will override any one of the style. so to solve this problem add class to differentiate this styles, like:
about.css
.about-component.container{
max-width: 400px;
}
contact.css
.contact-component.container{
max-width: 500px;
}
If you want apply only when the component is mounted, you can use the lifecycle.
The follow example is based in the idea you are using sass, React, sass-node and have the loaders into webpack.
<pre>
import React from 'react';
import './styles.scss';
class MyComponent {
constructor(props) {
super(props);
this.state = { className: '' }
}
componentDidMount() {
this.setState({
className: 'myOwnClass'
});
}
render(){
return (
<div className={this.state.className}>This is a example</div>
);
}
}
export default myComponent;
</pre>
To be able to only call that specific CSS when you need it you can use CSS Modules. You may need to update your version of react.
When saving your CSS file save it with a ".module.css" eg. "styles.module.css". The CSS in these files can only be used and accessed by hte components where are they are imported. As stated in a tutorial from W3Schools.
Let's say this is your CSS code in styles.module.css:
.container {
color: white;
}
.cont-child {
background-color: red;
}
Then in your JS file you can import the CSS file like this if the JS and CSS files are in the same directory. Make sure you point to the correct path.
import styles from './styles.module.css'
Then in your HTML section you can use it like this:
class Home extends React.Component {
render() {
return(
<main className={ styles.container } >
<div className={ styles["cont-child"]} >
Some div text about something...
</div>
</main>
);
}
}
I currently use both ways to access the selectors, since the styles variable acts like an object. I placed both of them here because the second option is capable of fetching selectors named like "btn-active". Which comes in handy in some situations. Camelcasing is considered cleaner though.
Please note: I originally posted this answer as a reply to a similar question here React CSS - how to apply CSS to specific pages only
I want to be able to apply a CSS stylesheet to specific components
only when they are loaded.
Why not apply the styles inline via React.js?
Step 1. Create the style object for the component:
var componentOneStyle = {
color: 'white',
backgroundColor: 'red'
};
Step 2. Populate the component's style attribute with the style object:
ReactDOM.render(<div style={componentOneStyle}>This is Component One</div>, mountNode);

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