Hi i have this myStyle object - but i have to apply class on h1 . How can i convert this myStyle into class.I tried this but its not working. its showing object when i inspect the elements.Height i am calculating dynamically based on the device height
class MyHeader extends React.Component {
deviceHeight=()=>document.height+"px";
render() {
const mystyle = {
height: deviceHeight
backgroundColor: "DodgerBlue", };
return (
<div>
<h1 className={mystyle}>Hello Style!</h1>
<p>Add a little style!</p>
</div>
);
}
}
you can't do this if you want to apply dynamic css then you can do it like this way. Add below tag in your jsx before the class tag you are trying it will genrate dynamic css in your component code and you can apply it.
<style>
{`\
.mystyle{\
height:${deviceHeight}px;\
background-color:'red'\
}\
`}
</style>
Change className to style.
Ref: https://reactjs.org/docs/dom-elements.html#style
Here you are not giving the dynamic value for height so simple thing is to create one class write CSS for that class and add class to h1 tag
///CSS Code ///
.heading{
height: '20px';
backgroundColor: "DodgerBlue";
}
/// React code
class MyHeader extends React.Component {
render() {
return (
<div>
<h1 className='heading'>Hello Style!</h1>
<p>Add a little style!</p>
</div>
);
}
}
try this code: style={mystyle}
if you want inject props to css codes you should use styled-component library: https://styled-components.com/docs/basics#passed-props
To use className to style your property what you can do is create a different css module and put your css stylings there
For example:
Header.css
.header {
height: 100vh; //since you're using device height
background: DodgerBlue
}
Now in your component import that css file
import styles from './Header.css';
Next in your h1 tag
<h1 className={styles.header}>Hello Style!</h1>
this way you can use class name for styling.
I have a component that relies on external stylesheets. I'm bringing the stylesheet into the component like this:
Child component
export default class Child extends Component {
render() {
return (
<div>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.4.0/css/font-awesome.min.css" />
...my code here...
</div>
);
}
}
But what's happening is this is forcing those styles onto the parent component as well.
Parent Component
export default class Parent extends Component {
render() {
return (
<div>
...code here...
<Child />
... more code here...
</div>
);
}
}
Is anyone aware of a way that I can keep that stylesheet link localized to just that child component so the styles aren't applied to the parent component as well?
Edit 2
Currently trying the shadow dom route, trying to pass down some children. Getting an error after the initial render saying Cannot read properties of undefined (reading 'children'). It does render the this.props.children initially...
import React, { Component } from 'react';
class MyComponent extends HTMLElement {
constructor() {
super();
const shadow = this.attachShadow({ mode: 'open' });
shadow.innerHTML = `
${this.props.children}
`;
}
};
export default class Child extends Component {
render() {
return (
<div>
<script>
{!customElements.get("my-component") && customElements.define('my-component', MyComponent)}
</script>
<my-component>
<h1>Hello from shadow</h1>
</my-component>
<h1>Hello</h1>
</div>
);
}
}
You can try CSS Modules. Add :local(.className) to the class you want to use in your code which is in the font-awesome-min.css file. Then import the styles to your component. For example import styles from './font-awesome-min.css' then use the module in your code. The styles will only apply to specific element and won't affect other elements in the document. So let's say you have a class called .usericon in your css you do this in the css file.
CSS
:local(.usericon){
fill: red;
}
React Code
import styles from './font-awesome-min.css'
export default function Profile(){
return (
<i className={styles.usericon}>User Icon</i>
)
}
One way to truly isolate your CSS is with Web Components. Web Components are a browser API that allows defining custom elements with their own "shadow DOM". If a style is defined inside the shadow DOM, it is truly sandboxed with no styles going in or out. You can use whatever selectors you like:
class FancyBox extends HTMLElement {
constructor() {
super();
const shadow = this.attachShadow({ mode: 'open' });
shadow.innerHTML = `
<style>
.fancy-box {
border: solid 3px darkblue;
background: dodgerblue;
padding: 10px;
color: white;
font: 16px sans-serif;
}
</style>
<div class="fancy-box">
<slot></slot>
</div>
`;
}
}
customElements.define('fancy-box', FancyBox);
.fancy-box {
border: dashed 3px darkred !important;
background: crimson !important;
padding: 10px !important;
color: white !important;
font: 16px sans-serif;
}
<fancy-box>Safe in my shadow DOM</fancy-box>
<div class="fancy-box">I am affected by outside stylesheets</div>
Note the use of <slot></slot>. This is a placeholder for child elements of the component.
If I wanted to use this custom element from React, it needs to be defined separately so it only runs once.
class FancyBox extends HTMLElement { /*...*/ };
customElements.define('fancy-box', FancyBox);
class ReactFancyBox extends React.Component {
constructor() {
super();
this.state = { value: 'hello world!' }
}
handleChange(e) {
this.setState({ value: e.currentTarget.value });
}
render() {
return (
<div>
<fancy-box>
<strong>{this.state.value}</strong>
</fancy-box>
<input value={this.state.value} onChange={e => this.handleChange(e)} />
</div>
);
}
};
My REACT component's code is like this
import React from 'react';
import { Twemoji } from 'react-emoji-render';
import emoji.css;
const emoji = () => {
return ( <Twemoji className="Twemoji" text=":+1:"/> );
}
export default emoji;
My css file (emoji.css) has the following code
.Twemoji {
width: 20em;
height: 20em;
}
but the size of the emoji doesn't change.
if I inspect the element and modify the inline style in the page html that works
Please can you help me understand how I can increase the emoji size via CSS
Twemoji Component does not take a prop className (see here), instead you will have to use the options prop in order to pass a custom css classname
const options = { className: "Twemoji" };
const emoji = () => {
return ( <Twemoji text=":+1:" options={options} /> );
}
EDIT:
you would also have to add !important to width and height in the css class to take precedence over the element style (see css precedence)
.Twemoji {
width: 4em !important;
height: 4em !important;
}
I have the following VUE component:
<template>
<div>
<div class="bottom-footer">
{{msg}}
</div>
</div>
</template>
<script>
export default {
name: 'LayoutFooter',
data () {
return {
msg: 'my test'
}
},
mounted () {
}
}
</script>
<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
.bottom-footer {
height: 200px;
background-color: #A7BFE8;
}
</scoped>
VUE is completely ignoring my scoped CSS. When page is rendered its simply not applied. There are no console errors. Ive tried removing the scoped attribute and its still ignored. Any ideas why VUE is doing this?
<style scoped>
.bottom-footer {
height: 200px;
background-color: #A7BFE8;
}
</style>
you need to close style
I'm new to vue.js. Here is my problem:
In a *.vue file like this:
<template>
<div id="a">
</div>
</template>
<script>
export default {
name: 'SquareButton',
props: ['color']
}
</script>
<style scoped>
#a {
background-color: ?
}
<style>
How can I use the props color in background-color: (where is a ? now).
Thanks.
You actually can!
You should define the CSS variables in a Computed Property, then call the computed property as a style attribute to the element that will require the CSS variable, and finally you may use the variable within the tags at the bottom of your document.
new Vue({
el: '#app',
data: function() {
return {
baseFontSize: 1,
bgHoverColor: "#00cc00",
hoverContent: "Hovering!"
}
},
computed: {
cssProps() {
return {
'--hover-font-size': (this.baseFontSize * 2) + "em",
'--bg-hover-color': this.bgHoverColor,
'--hover-content': JSON.stringify(this.hoverContent)
}
}
}
})
div {
margin: 1em;
}
div.test:hover {
background-color: var(--bg-hover-color);
font-size: var(--hover-font-size);
}
div.test:hover::after {
margin-left: 1em;
content: var(--hover-content);
}
<script src="https://unpkg.com/vue/dist/vue.js"></script>
<div id="app" :style="cssProps">
<div>Hover text: <input type="text" v-model="hoverContent"></div>
<div>Hover color: <input type="color" v-model="bgHoverColor"></div>
<div class="test">Hover over me</div>
</div>
Or have a look here: https://codepen.io/richardtallent/pen/yvpERW/
And here: https://github.com/vuejs/vue/issues/7346
You don't. You use a computed property and there you use the prop to return the style of the div, like this:
<template>
<div id="a" :style="style" #mouseover="mouseOver()">
</div>
</template>
<script>
export default {
name: 'SquareButton',
props: ['color'],
computed: {
style () {
return 'background-color: ' + this.hovering ? this.color: 'red';
}
},
data () {
return {
hovering: false
}
},
methods: {
mouseOver () {
this.hovering = !this.hovering
}
}
}
</script>
<style scoped>
<style>
As we are in 2020 now, I suggest using this trick with a css function called var
<template>
<div id="a" :style="cssVars"></div>
</template>
<script>
export default {
props: ['color'],
computed: {
cssVars () {
return{
/* variables you want to pass to css */
'--color': this.color,
}
}
}
<script>
<style scoped>
#a{
background-color: var(--color);
}
</style>
This method is very useful because it allows you to update the passed values through css later on (for example when you apply hover event).
credit
I know we're talking vue 2 here, but in case anyone from vue 3 lands in this question (like I did), vue 3 introduced a much cleaner way to do this:
<template>
<div id="a">
</div>
</template>
<script>
export default {
name: 'SquareButton',
props: ['color']
}
</script>
<style scoped>
#a {
background-color: v-bind(color);
}
<style>
What Vue actually does behind the scenes is the same "introducing css variables through component's style process", but it sure looks much better on the eyes now.
Documentation source: https://v3.vuejs.org/api/sfc-style.html#state-driven-dynamic-css
Why not just use :style prop in this way:
<template>
<div :style="{ backgroundColor: color }">
</template>
<script>
export default {
props: {
color: {
type: String,
default: ''
}
}
}
</script>
Make sure you define css properties in camelCase style.
If you need css that can't be applied by a style attribute like pseudo classes or media queries, what I do is the following:
Create a globally available style component when initializing Vue (you need it as otherwise you run into linting issues). It creates a style tag that simply renders the content in the slot:
I would only use this if you really need both dynamic values in your css and css features that can't be applied to a style attribute.
import Vue from 'vue'
import App from './App.vue'
import router from './router'
import store from './store'
Vue.config.productionTip = false
Vue.component('v-style', {
render: function(createElement) {
return createElement('style', this.$slots.default)
}
})
new Vue({
router,
store,
render: h => h(App)
}).$mount('#app')
Then use it at the top of your template like this and you get the full JavaScript scope of your component and the full css syntax combined:
<template>
<v-style>
#media screen and (max-width: 820px) {
.gwi-text-media-{{ this.id }} {
background-image: url({{ mobileThumb }});
}
}
</v-style>
</template>
It seems a bit hacky to me, but it does it's job and I would rather go like this in some cases than having to add additional JS for mouse-over or resize events that have a big potential to slow down your application performance.
Vue 3 added new way of binding styles, so now you can easily bind your props to css properties.
Read source:
https://learnvue.co/2021/05/how-to-use-vue-css-variables-reactive-styles-rfc/
<template>
<div>
<div class="text">hello</div>
</div>
</template>
<script>
export default {
data() {
return {
color: 'red',
}
}
}
</script>
<style>
.text {
color: v-bind(color);
}
</style>
You could utilise the CSS var(--foo-bar) function. It is also useful if you are trying to pass an asset that has its own dynamic path, like Shopify does.
This method also works for styling the :before and :after elements as they refer back to the style applied on the owner element.
Using the original post example for passing a colour:
<template>
<div
id="a"
:style="{ '--colour': color }">
</div>
</template>
<script>
export default {
name: 'SquareButton',
props: ['color']
}
</script>
<style scoped>
#a {
background-color: var(--colour);
}
</style>
Using the original post example for passing an URL:
<template>
<div
id="a"
:style="{ '--image-url': 'url(' + image + ')' }">
</div>
</template>
<script>
export default {
name: 'SquareButton',
props: ['image']
}
</script>
<style scoped>
#a {
background-url: var(--image-url);
}
</style>
Source