How to override css of other components from App - css

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`} />
)
}

Related

How do I override global styles in nextJS

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.

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).

Ho do I add common css for stenciljs web-components

I am creating bunch of web-components, not sure how do I create common css for stenciljs web-components.
Based on documentation I can add globalStyle: 'src/global/app.css',
But it seems i can only share css variables. e.g.
:root {
--font_color: #484848;
--bg_color--light: #f9f9f9;
}
if I want to have common base css for buttons e.g.
button {
border-radius: 5px;
padding: 2px 10px;
}
Which i want to share across all the components | Not sure how to achieve that.
Thanks in advance for suggestions.
The globalStyle stylesheet gets distributed along with your app and can indeed be used to write global CSS. E. g. for the www output target, it gets generated as /build/<namespace>.css, and you can then include it into your app with a link:
<link rel="stylesheet" href="/build/my-app.css" />
However you can't use it to provide base css for elements that are inside a custom element with Shadow DOM enabled (i. e. if you have shadow: true in the component decorator).
So, as a solution you can use sass partials and modules to achieve what you're trying to do.
// src/styles/partials/_button.scss
button {
border-radius: 5px;
padding: 2px 10px;
}
// src/components/my-button/my-button.tsx
#Component({
tag: my-button,
shadow: true,
styleUrl: 'my-button.scss',
})
export class MyButton {
render() {
return <button>Click me</button>
}
}
// src/components/my-button/my-button.scss
#use '../../styles/partials/button';
The Stencil docs are a bit unclear on this issue. It took me a while to realize the globalStyle config doesn't actually do anything to apply global styles to components with shadow DOM.
If you wish to use the globalStyle globally across all components, you can try the following:
Link the globalStyle inside your index.html
Also link the globalStyle inside each of your components
The components may seem strange with a style link, but it actually works.
render() {
return (
<Host>
<link rel="stylesheet" href="/build/my-app.css" />
RENDER THIS COMPONENT WITH GLOBAL STYLES
</Host>
);
}

How to load different .css files on different components of a react application?

I have two .jsx files that represent their respective components.
The first one is, Blog.jsx
import React from "react";
import '../assets/css/blog.css';
export const Blog = () => (
<div>
<h1>Hello Blog</h1>
</div>
)
With its respective CSS file, blog.css
div { background: #ff481f; }
and the second one is, Landing.jsx
import React from "react";
import '../assets/css/landing.css'
export const Landing = () => (
<div>
<h1>Hello Landing</h1>
</div>
)
With its respective CSS file, landing.css
div { background: #86ff2b; }
I have added routing and called instances of those two components on the App.js file which is the default file of a React application. After running the application, when navigated to components, I faced a problem that the background color is the same for both of the components (It loads landing.css only and never changes).
How can I fix that problem that each component only uses its respective .css file and loads it?
By default webpack and other build tools will compile all CSS files into one, even if css was imported in separate JSX files. So you can't use different CSS files and expect you don't affect on another part of page.
You have some options:
Use BEM for naming class names.
Use cssModules. In this case elements will have their own css class name and styles will not affect any other elements except if you use :global selector.
css-module
Using html tags as css selectors is a bad practice (because there is the behaviour you describe).
You should use only css classes or inline styles (using id's is another bad practise, id's have high priority).
div {
width: 20px;
height: 20px;
}
#id {
background: red;
}
.class {
background: green;
}
<div id="id" class="class"></div>
In case using css classes there is the same problem (when you have two similar classes). And this case is decided using css modules (set of rules of building) or you can use css-in-js (external library) which has its pros and cons. Also you can use BEM (methodology) and if your application is not big you can avoid this trouble.
css modules will add to your classes random hash and instead .my-awesome-class-name you will get .my-awesome-class-name-dew3sadf32s.
So, if you have two classes .class in the first file and .class in the second file in the end you will get two classes .class-dew23s2 and .class-dg22sf and you styles will resolve as expected.
css-in-js is a similar way except you should write your styles using javascript with some profits like including only those styles that are needed at the moment (what you are looking for right now) and several others.
You can code using pure css / scss / postcss / etc but many companies already choose between css modules and css-in-js.
BEM is just naming conventions for your class names.
And lastly - if you use inline-styles using react you should remember:
{} is constructor of object and {} returns new object on every call, it's mean if you write something like:
class MyAwesomeComponent extends Component {
render() {
return <div style={{color: "red"}}></div>;
}
}
or
class MyAwesomeComponent extends Component {
render() {
const divStyles = {color: "red"};
return <div style={divStyles}></div>;
}
}
div will re-render every time your render will call because div takes new prop.
Instead, you should define your styles (for example) in outside of your class:
const divStyles = {color: "red"};
class MyAwesomeComponent extends Component {
render() {
return <div style={divStyles}></div>;
}
}
Don't define your css using HTML tags because it will affect your entire application.
use className,id or inline styling.
like- App.css
.myApp{ color: red;}
#myApp2{ color: blue;}
App.js
import './App.css'
<div className="myApp">color changed by className</div>
<div id="myApp2">color changed by id</div>
<div style={{color:'red'}}>color changed by inline object styling</div> // inline styling
This is not the best solution if you are looking forward to improve yours css imports/loads.
However could be the best solution if you dont want to go in deep in css, resolve the problem fast and keep working with HTML tag.
You can add a div for each component, define an Id for the div and wrap the component. Afterwards in the component's css fies you are going to define all the styles starting with the #id so all the css classe or HTML tag will affect just the corresponding component.
//App render in root
ReactDOM.render(
<App />,
document.getElementById('root')
);
//App
function App(props){
return [
<Blog />, <OtherComponent />
]
}
//Blog component
function Blog(props){
return <div id="blog">
<h1>I am Blog</h1>
</div>
}
//Other component
function OtherComponent(props){
return <div id="otherComponent">
<h1>Im am other component</h1>
</div>
}
/* blog.css*/
#blog h1{
color:yellow;
}
/* otherComponent.css*/
#otherComponent h1{
color:green;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<div id="root"></div>

CSS Modules & ReactJS: Parent and child CSS classes in different components

So I am building a react application and have a quick question. If I have two separate components:
and
with CSS classes navigation.css and navigationLogo.css respectively. In navigation.css I have a class named .main and in navigationLogo.css I want to have a class like so:
.main .main_in_logo {
color: red;
}
But with CSS Modules I am unable to do this, any ideas on a work around?
I just feel that the explanations here are not complete enough. In css you do .parentSelector .childSelector in order to select the child. The same rule is for css modules, but in your html/jsx you should add to the parent and the child the relevant className -> styles.parentSelector , styles.childSelector.
<div className={styles.container}>text</div>
This way you can have in your css something like:
.banner .container{
background-color:reb;
}
.banner .container{
background-color:blue;
}
Sometimes you use libraries and you want to change something somewhere down the DOM inside the library and you can't change its source code. In this case you can use the :global like this:
.parentElement :global(div)
.parentElement :global(#some-lib-element-selector)
I was looking for the same problem and didn't find the solution here, maybe because the post is 3 years old. The accepted answer is, in my opinion but not mine only, not scalable.
I don't really know if this is something new, but I found out what I would do in vanilla CSS adapted to CSS modules.
Here is what I did and fully suits my needs:
/* parent.css */
.main {
...some CSS...
}
/* logo.css */
#value main from "./parent.css";
.logo {
...some CSS...
}
.main .logo {
color: red
}
Here, we are using #value, which is a CSS modules variable and allows us to bind with another file to build a selector including the final name of the parent "main".
As strange as it looks to me, it took some time to find out about this solution, I hope this will save some time and help other people!
Why you need to create .main .main_in_logo - the main idea of styles with parent elements its not to broke your css with other styles in the future. But its impossible with css modules, because your styles will be unique forever.
But even you really need it you can use global css for these 2 components - documentation about global css for react-css-modules.
The child component should not have a css rule that is dependent upon the parent css classname.
the child should just be:
.main_in_logo { color: red; }
If you need to define styles that involve both parent and child, then the easiest way is to define the styles completely in the parent:
/* navigation.css */
.main .main_in_logo {
color: red;
}
Then have the parent pass the css class to the child and tell the child to use it:
// Navigation.js
<NavigationLogo className={navigationCss.main_in_logo} />
// NavigationLogo.js
<div className={"foo " + this.props.className}>stuff</div>
You don't need to be specify which child class you are referring to when using CSS modules in ReactjS.
so doing:
.main_in_logo {
color: red;
}
will be enough in the stylesheet.
I ended up using CSS the normal way but with BEM convention.
I mean after all, what the CSS modules do is adding the [this_name].module.css to your css classes anyway. If you typed it correctly in the first place, there's no need of using this. It's just a new abstract that allow newbies so they can just do stuff without having to worry about class names clashing.
// Main.jsx
import './Main.css'
import Logo from './Logo.jsx'
const Main = () => {
return (
<div className="main">
<Logo className="main__logo" />
</div>
)
}
/* Main.css */
.main {/* do magic */}
.main__logo {/* do magic but for Logo component */}
So maybe you had Logo component like this..
// Logo.jsx
import './Logo.css'
const Logo = () => {
return (
<div className="logo">
<img className="logo__img" />
</div>
)
}
/* Logo.css */
.logo {/* do magic for logo */}
.logo__img {/* do magic for logo's image */}
This feels much more natural.

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