I am using React Typescript.
How do I add image to my button?
I tried doing it and there are no errors, but I am getting a blank button.
How do I style my button element using Emotion CSS here?
import React from "react";
function PostButton(props){
let style = {
width:24,
height:24,
src: "../images/abc.png"
};
return(
<button style={style} onClick={() => props.handleClick()}>{props.label}</button>
);
}
return (
<div style={style}>
<PostButton src={"../images/abc.png"} handleClick = {props.incrementScore}/>
</div>
);
}
src would be background:url(../images/abc.png)
Perhaps you're confusing the src prop that an img HTML element would have?
Perhaps you should include a nested img component inside your button.
Working example: https://stackblitz.com/edit/react-emotion-hello-u9qyaa
Damian's answer is technically correct however if you're using webpack you'll need to import the image like this:
import abc from "../images/abc.png";
And use it like this:
function PostButton(props){
let style = {
width:24,
height:24,
background: `url(${abc})`,
};
return(
<button style={style} onClick={() => props.handleClick()}>{props.label}</button>
);
}
Related
So, I'm trying to create a React App that changes the background image of the body. I did this by giving the body in my index.html an id of "body." I can get this to work with changing the background COLOR just fine. When I try to reassign the background IMAGE, though, I can't seem to get it to work no matter what I try.
This works:
document.getElementById("body").style.backgroundColor = "blue";
This doesn't:
import explosion from "./explosion.png";
function Boom(){
document.getElementById("body").style.backgroundImage = "url('" + {explosion} +
"')";
Why? I've tried writing this many different ways.
this worked for me :
import { useEffect } from "react";
import img from './img.png';
export default function App(){
useEffect(()=>{
document.getElementById('body').style.backgroundImage = `url('${img}')`;
})
return <>
<div id="body"
style={{height:'300px'}}
>
</div>
</>
}
or you can use inline css style :
import img from './img.png';
export default function App(){
return <>
<div id="body"
style={{
height:'300px',
backgroundImage: `url('${img}')`,
}}
>
</div>
</>
}
you need to pass the URL of the image as a string, without wrapping it in curly braces {}
You can try this code
import { useEffect } from "react";
export default function App() {
const bgUrl =
"https://images.unsplash.com/photo-1605106250963-ffda6d2a4b32?ixlib=rb-4.0.3&ixid=MnwxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8&auto=format&fit=crop&w=880&q=80";
/*useEffect Hook allows you to perform side effects in your components. Such as fetching data, directly updating the DOM, and timers*/
useEffect(() => {
Boom();
}, []);
const Boom = () => {
document.getElementById("body").style.backgroundImage = `url(${bgUrl})`;
};
return (
<div className="App">
<h1>Hello World!</h1>
</div>
);
}
here's a link to the working demo Change Background Image
Let's say you have a navbar and when you're using this component on your homepage you want it to have a certain background color and display property, but when you use that same navbar component on another page in your application you want to change these CSS properties. Seeing as the component has one CSS file linked how would you change the style of a component depending on where it is being rendered?
My personal favourite method nowadays is styled components. Your component might look something like this:
// NavBar.js
import styled from 'styled-components'
const StyledDiv = styled.div`
width: 100%;
height: 2rem;
background-color: ${props => props.bgColor};
`
const NavBar = (bgColor) => {
return <StyledDiv bgColor={bgColor}>
}
Then to use it in your different contexts you simply pass the color prop:
// homepage.js
<NavBar bgColor="red" />
// otherpage.js
<NavBar bgColor="#123ABC" />
Styled components are becoming a very popular way of doing things, but be aware that there are a huge array of ways you can do this.
https://styled-components.com/
(Code not tested)
Well If you just want to use plain CSS then you can change the className based on route so the styles also changes.
Example:
import { useLocation } from "react-router-dom";
const Navigation = () => {
let location = useLocation();
...
return(
<nav className={location.pathname === "/home" ? "homepage-navbar" : "default-navbar"}>
...
</nav>
)
}
You can write longer condition for multiple pages as well.
Other better thing you can do is pass the location.pathname and value of className as prop.
import { useLocation } from "react-router-dom";
const Home = () => {
let location = useLocation();
...
return (
<>...
<Navigation location={location.pathname} styleClass={"homepage-navbar"}/>
</>
)
}
const Navigation = ({location, styleClass}) => {
...
return(
<nav className={location === "/home" ? styleClass : "default-navbar"}>
...
</nav>
)
}
So now you can pass different values for className from different components and get different styles for the navbar.
i am trying to toggle a class with useState, but i imported the class using module (not globally, xxx.module.css).
is it possible to toggle the class without changing them to global?
example:
import styles from 'xxx.module.css'
function app(){
const [active, setActive] = useState(false);
return()
<div className={active ? "active" : " "}><p>Hy there!</p> </div>
<button onClick={() => setActive(!active)}>toggle me</button>
}
export default app
with a css
.active{
display: flex;
}
its something like that, but if i use module to import css it won't really work since it require {styles.active} (i've already tried changing the class name to {styles.active} its not really working).
is there any way to work around this? thanks!
My solution:
import s from './x.module.css'
import {useState} from 'react'
const App = () => {
const [active, setActive] = useState(false)
return (
<div>
<div className={active ? s.active : null}>Hi world!</div>
<button onClick={()=> setActive(!active)}>Activate!</button>
</div>
)
}
x.module.css:
.active {
color: black;
}
I personally use the classnames library for this:
const className = classnames({ [styles.active]: active });
Alternatively, you can set up the functionality yourself:
const className = active ? styles.active : undefined;
and then: <div className={className}>
You must use className as styles.active and it must not be between quotation marks.
So your division tag must like that:
<div className={active ? styles.active : " "}>
...some JSX...
</div>
PS: The code you write here to specifing the problem have full of errors. I don't think in real code you did this terrible mistakes but I want to indicate this stiutaion.
So what's the best pratice for using className in react. In specific multiple class names. I'm reading through the documentation and I don't really get a clear answer. I've seen things like:
const divStyle = {
color: 'blue',
backgroundImage: 'url(' + imgUrl + ')',
};
function HelloWorldComponent() {
return <div style={divStyle}>Hello World!</div>;
}
but is there a way for me to do something like this?
import React from 'react';
import ReactDOM from 'react-dom';
import './css/landing.css';
import './css/w3.css';
class Home extends React.Component {
const homeClasses = 'bgimg-1 w3-display-container w3-opacity-min';
render() {
return (
<div className={homeClasses}>
<h1>SUP</h1>
</div>
);
}
}
ReactDOM.render(
<Home />,
document.getElementById('root')
);
or even just list then out in the class name section?
It depends what your component should/will do.
If your component is fairly static you will want to use a built in style like your first example:
const mystyle = {
width: '100%',
...
}
<div style={mystyle}>...</div>
However, there are better ways that allow your component to be more dynamic for re-use, for instance using a class method to generate the style from props passed to it, like in this render function:
render() {
// User's preference or Default Style:
const defaultStyle = {
width: this.props.style.width || '100%',
height: this.props.style.height || '100%',
}
//if this.props.className doesn't exist use mycssclass
const defaultClassName = this.props.className || 'mycssclass'
return (
<div className={defaultClassName} style={defaultStyle}>...</div> )
Following this logic you can use the ternary operator to change the css class name based on props. A common solution is use an isActive state property and use it to determine which class should be used.
render() {
const activeClassName = this.props.className + ' mycomponent-active'
return (
<div className={this.props.isActive ? activeClassName : this.props.className} style={ this.props.style }
</div>);
}
Another common, but complex way to set your component's style is to use a function that will return a given style object, and use it like the first example.
Ultimately, you should decided whether you would like your component to be styled by the designer/user or should look the same no matter where it is used... if it is styled by the designer, just expose the CSS class name from props to the component or define a default:
<div className={this.props.className || 'someclassName'}>...</div>
otherwise, use an example above.
Yes, you can do this! Take a look at the snippet below:
class Example extends React.Component {
cssClasses = 'demo demo2';
render() {
return (
<div className = { this.cssClasses }>
Hello World
</div>
);
}
}
ReactDOM.render( <Example/> , document.getElementById('app'));
.demo {
color: blue
}
.demo2 {
font-size: 20px;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id='app'></div>
Your error was the definition of the homeClasses. You can't declare it like
const homeClasses = '...';
Because, on the way that you did, homeClasses is a property of your component. You should not use const. Just:
homeClasses = '...';
And you forgot to use the this reference, because the homeClasses is an attribute of your component.
<div className={this.homeClasses}>
<h1>SUP</h1>
</div>
Exists and one away for this problem. You can use and read this data from file (example data.json) where can use this data like props of that.
A Button component is generally comprised of the Text element wrapped with a TouchableHighlight (or other touchable). I'm trying to create a Button component styled using styled-components, but am having trouble getting my style to respond dynamically to props.
Button Component
Below, I've created a Button component similar to the Adapting based on props example found in the styled-component docs.
import React from 'react';
import { Text, TouchableHighlight } from 'react-native';
import styled from 'styled-components/native';
const colors = {
accent: '#911',
highlight: '#D22',
contrast: '#FFF',
}
const Label = styled.Text`
color: ${props => !props.outline ? colors.contrast : colors.accent};
font-weight: 700;
align-self: center;
padding: 10px;
`
const ButtonContainer = styled.TouchableHighlight`
background-color: ${props => props.outline ? colors.contrast : colors.accent};
width: 80%;
margin-top: 5px;
border-color: ${colors.accent};
border-width: 2px;
`
const Button = (props) => {
return (
<ButtonContainer
onPress={props.onPress}
underlayColor={colors.highlight}
>
<Label>
{props.children}
</Label>
</ButtonContainer>
);
};
export default Button;
Button Usage
After importing it, I'm using the button like this...
<Button
outline
onPress={() => console.log('pressed')}>
Press Me!
</Button>
Expected Result
And so, I would expect my button to look like this...
Actual Result
But instead it looks like this...
What I've done to troubleshoot so far
When I inspect using react-devtools, I can see that the outline prop is being passed down to the Button component.
But the prop is not passed down to any of it's children
The Passed Props part of the docs state, "styled-components pass on all their props", but I guess not all the way down?
My Question
What do I need to change so that I can dynamically style my Button based on it's props?
Here you have:
const Button = (props) => {
return (
<ButtonContainer underlayColor={colors.highlight}>
<Label>
{props.children}
</Label>
</ButtonContainer>
);
};
If ButtonContainer was a normal React component, you wouldn't expect the props passed to Button to be automatically passed to ButtonContainer. You'll have to do <ButtonContainer underlayColor={colors.highlight} {...props} /> to do it.
Actually ButtonContainer is a normal React component, the only difference is you pre-apply some styles using an HOC.
Also if you desugar this to a React.createElement call, you can see there's no way props can be passed automatically, because a Function's arguments don't get passed automatically to the function calls inside it.
const Button = (props) => {
return React.createElement(ButtonContainer, { underlayColor: colors.highlight }, ...);
};
It's nothing specific to styled-components. You just have to pass down the props yourself to ButtonContainer, as well as to Label.
So you'd rewrite your code to:
const Button = (props) => {
return (
<ButtonContainer underlayColor={colors.highlight} onPress={props.onPress} outline={props.outline}>
<Label outline={props.outline}>
{props.children}
</Label>
</ButtonContainer>
);
};
Technically a React component can pass down props to it's children, so ButtonContainer could pass them down to Label using React.Children and React.cloneElement APIs. But ButtonContainer doesn't do that for obvious reasons, e.g. you'd not want underlayColor and onPress to be passed to Label automatically. It would cause a lot of confusing bugs.