How to have different styles for common componnent instance in Angular? - css

I have a component called the amount component which is a shared library and I want to use that component in multiple places and I want to give that component different styles from where i use it. How to achieve it in angular ?
PS: amount component, needs styles for background, h2, button.

You can give custom styles to your account-component by adding an Input Attribute by using the #Input() Decorator & pass the styles or class name to that component depending upon where it is opened from.
Then you can use ngClass or ngStyle to apply those styles to your component.
For example in your account-component:
export class AccountComponent implements OnInit {
#Input() customClass: string;
}
Account Component HMTL
<div [ngClass]="customClass"> <h1>Account Component</h1> </div>
Account Component CSS
customClassRed:{
color: red;
}
customClassBlue:{
color: blue;
}
and in your components where you are opening account-component from just pass the class name (if you use the class name, then you need that class with styles in your components.css as I did above) or the styles depending upon your preferences
Another Component
<account-component [customClass]="customClassBlue"> </account-component>

Related

How to use components in different ways (React)

I want to use simple components in different way and different ui rendering
For example a dropdown rendering a list may have several ui according to the page or context (=> padding, margins, font size and other css properties might change)
should I:
implement it by overwriting in the parent component (target css properties of the child component and apply them my css needs - at cost that if change happens in the child component like change in classname or what might break the parent design)
Pass flags to the component to handle those design and at cost that each component handle the design of each parent
There are different approaches to this and everybody has his own preferences.
I usually solve this by supporting the className property. The class is accepted as a prop and applied to the root. So it is easy to change things like outer margins or the background-color. I usually discourage modifications of deeply nested elements.
Example:
import classnames from 'clsx';
import style from './button.module.scss';
export const Button = ({ content, onClick, className }) => {
return (
<div
className={classnames(style.buttonRoot, className)}
onClick={onClick}>
{content}
</div>
);
};
and if I want to modify it anywhere I can do it thus:
import { Button } from './Button';
import style from './productView.module.scss';
// ...
<Button content={'Show products'} className={style.showProdButton} onClick={showProd} />
and
.show-prod-button {
background-color: #562873;
margin-left: 32px;
}

How to style Antd component

I am working on Switch component with antd library. I would like to change background of switch, so I have following code:
import styled from 'styled-components';
import { Switch as SwitchhAnt } from 'antd';
export const Button = styled(SwitchhAnt)`
.ant-switch-checked {
background-color: red;
}
`
But switch background does not change at all. I know I can wrap this in some container and it will works but why something like that does not works?
As per how styled components work under the hood,
It creates a unique class name by hashing styles into a seemingly-random string, like dKamQW or iDwMsQ.
Then inject a new CSS class into the page, using that hashed string as its name, and containing all of the CSS declarations from the styles string. You can see that when you inspect switch that different style classes have been applied.
Normal antd Switch
Styled antd Switch
So here you don't need to add the class name used by antd. Just only need to add CSS properties that need to have like below.
export const Button = styled(SwitchAnt)`
background-color: red;
// ....... other styles
`
You can check example codesandbox in here.
You can also refer demystifying-styled-components and how-styled-components-works for more details about what styled components do under the hood.

How to dynamically generate CSS class and/or set its property

The title is not really a question it is more like an idea, I don't know what approach is best for my situation.
So, the problem. I have some 3rd party component that have some complex structure and styling. Some part of it has some predefined CSS class that I can override with CSS in my surrounding component. Something like this:
my component:
<div class="my-cmp-container">
<some-3rd-party-cmp></some-3rd-party-cmp>
</div>
3rd party component:
<div class="3rd-party-css-class">
...
</div>
For example, 3rd-party-css-class has style background-color: #f00, I can override it with .my-cmp-container .3rd-party-css-class { background-color: #fff; } etc. But. What if I need to set color dynamically, it's stored in a DB for example and I can't predefine each case in my class' CSS. I just have the color in hex.
In theory I can generate unique string to set as CSS class for every instance of some-3rd-party-cmp and somehow generate CSS in my component? I'm lost a little, what is the best approach for this?
Edit: Code sample to illustrate the situation https://stackblitz.com/edit/angular-kxdatq
What you are trying to do is the subject of this open issue about stylesheet binding in Angular. Until that feature is available, you can get what you want with a custom directive. Here is a directive that retrieves the checkbox element generated by ng-zorro-antd and applies two color attributes to it. The two colors are #Input properties and the directive implements OnChanges which allows to react to property binding changes.
#Directive({
selector: "[nz-checkbox][nz-chk-style]"
})
export class CheckBoxStyleDirective implements OnInit, OnChanges {
#Input("nz-chk-bkgnd") chkBkgndColor: string;
#Input("nz-chk-border") chkBorderColor: string;
private checkbox: HTMLElement;
constructor(private renderer: Renderer2, private el: ElementRef) { }
ngOnInit() {
this.checkbox = this.el.nativeElement.querySelector(".ant-checkbox-inner");
this.updateBackgroundColor();
this.updateBorderColor();
}
ngOnChanges(changes: SimpleChanges) {
if (changes.chkBkgndColor) {
this.updateBackgroundColor();
}
if (changes.chkBorderColor) {
this.updateBorderColor();
}
}
updateBackgroundColor() {
if (this.checkbox) {
this.renderer.setStyle(this.checkbox, "background-color", this.chkBkgndColor);
}
}
updateBorderColor() {
if (this.checkbox) {
this.renderer.setStyle(this.checkbox, "border-color", this.chkBorderColor);
}
}
}
Once the directive attribute selector nz-chk-style is applied to the 3rd party element, you can set the checkbox background and border colors with property binding as follows:
<span nz-checkbox nz-chk-style [nz-chk-bkgnd]="bkgndColor" [nz-chk-border]="borderColor" >
See this interactive stackblitz for a demo.
Not sure if you are using Angular but you tagged it, so I guess you are.
If you want to change only the color and nothing more, instead of having a .3rd-party-css-class class, you could just have your with an ng-style like so:
<some-3rd-party-cmp ng-style="{ color: your_color_hex_variable }"></some-3rd-party-cmp>
You can also define a whole object if styles and pass it.
You can also use ng-class and pass one or an array of class names what you want to put additionally on your component:
<some-3rd-party-cmp ng-class="[cls1, cls2, cls3]"></some-3rd-party-cmp>
<some-3rd-party-cmp ng-class="[3rd-party-css-class, someCondition ? 'another-class-name' : '']"></some-3rd-party-cmp>
In the classes you can define the css rules you want to apply and thats it.
With this solutions you can avoid having extra wrapper elements for styling purposes which is a nice thing.

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);

Applying dynamic styling to injected HTML in Angular 2

For an Angular project I'm working on, I'm injecting HTML into a <div> like so:
<div class="myClass" [innerHTML]="htmlToInsert"></div>
The htmlToInsert contains a variety of things, notably <a> tags. Previously we were styling all these tags like so:
.myClass ::ng-deep a {
color: #f00;
text-decoration: none;
}
And this worked fine. But now I need the color of these links to be dynamically generated during component initialization, based on data coming in from elsewhere. All of the dynamic styling I've seen in Angular requires you to apply things directly to the HTML tag, but we don't have them here to work with.
How can I apply dynamic styling to HTML that is also dynamically generated? Can I directly change the CSS class somehow? Would using a pipe be the correct approach here? Is there another method I don't know about? I could maybe refactor code if there is absolutely no other way of doing this.
So if you can't modify the innerHTML you are passing in, you can achieve this functionality with a custom directive. Essentially you would tag your div that contains your innerHTML with a custom directive. That directive then looks for any anchor tags in it and changes the color based on an input.
// component.html
<div anchorColor [color]="dynamicColor" [innerHTML]="htmlToInsert"></div>
// directive.ts
#Directive({selector: '[anchorColor]'})
export class AnchorColorDirective implements OnAfterViewInit {
#Input() color: string;
constructor(private el: ElementRef){
}
// afterViewInit lifecycle hook runs after DOM is rendered
ngAfterViewInit(){
// get anchor element
let anchorEl = this.el.nativeElement.querySelector('a');
// assign color
if(anchorEl){
anchorEl.style.color = this.color;
}
}
}
Here is a working plunkr https://plnkr.co/edit/QSYWSeJaoUflP94Cy4Hm?p=preview

Resources