I'm using a third party component.
I have two classes named Parent and Child. In Parent component I use that third party component which accepts a class name as a prop and renders in itself.
So the parent component looks like this:
render(){
return (
<div className="section">
<Select
placeholder={placeholder}
valueComponent={Child}
/>
</div>
);
What I want to do is to pass some props to Child component, but I've always done this like <Child someProp="prop"/>.
Is there any way to pass props to Child component in this manner?
I don't know if the Select library provides a way to do that. In case, you could always use a wrapper component:
// Create a child wrapper component and pass it to Select.
function ChildWrapper(props) {
return <Child {...props} someProp="prop" />;
}
render(){
return (
<div className="section">
<Select
placeholder={placeholder}
valueComponent={ChildWrapper}
/>
</div>
);
}
Related
I need to pass props from wrapper to child component
Have a structure like this:
CabinetBlockContainer.jsx
smallChild.jsx
Right now my smallChild.jsx looks like:
return (
<CabinetBlockContainer>
<div className={props.className}>
<Typography variant="h6" color="primary">
{props.title}
</Typography>
<Typography variant="caption">{props.subtitle}</Typography>
</div>
<BalanceSmallBlock balance="1254.51" needIcon={props.needIcon} />
</CabinetBlockContainer>
);
and my container looks like:
return (
<div className={props.className}>
<div className="block-wrapper" >
</div>
</div>
);
})
I have many styles for my blocks, that's why I created wrapper(CabinetBlockContainer). I need to pass props from my CabinetBlockContainer to its child component. I don't really know is it the best practice, but seems normal.
I have tried to find in documentation how to pass props like this, but have any solution.
Use {props.children} inside your wrapper, it seems you want to do something like this.
You can pass props to a children while cloning it with new props
for better understanding how props and state work please refer this
and here is an example of previously answered same question on SO
In React Native you can encapsulate a set of components in one single <View> (or similar) component. You can also encapsulate a set of components as <> and </>. What are these? Do they just translate to an base View? It's probably not a good practice but it doesn't give a warning and it doesn't crash.
It's the React shortcut for Fragment component.
You can write like this :
import React, { Component } from 'react'
class Component extends Component {
render() {
return <> <ComponentA/> <ComponentB/> </>
}
}
Or without the shortcut and import Fragment component
import React, { Component, Fragment } from 'react'
class Component extends Component {
render() {
return <Fragment> <ComponentA/> <ComponentB/> </Fragment>
}
}
You have to know, you can't use any key or prop with the shortcut syntax.
Here's the official documentation
I hope it helps !
In addition to what He has said, it is used to embed many HTMLElements that you don't what them to be nested into a <div> for example.
For example, you may have this use cases
render() {
return (
<React.Fragment>
<ChildA />
<ChildB />
<ChildC />
</React.Fragment>
);
}
For more explanation you can read this React Official Documentation Fragment
In react <> and </> is just a syntactic sugar for <React.Fragment> . What it basically means is all components should be wrapped in a parent element. So without disturbing the whole schematic design <> provides a wrapper to wrap all your elemnts inside it .
<React.Fragment>
// your code
</React.Fragment>
is same as
<>
// your code
</>
hope it helps
One of the highlights of React v16.2 is Fragments.
If you're working with React projects, you may be familiar with wrapping your child components with <div> or <span> in your render().
Fragment is a first-class component that you can use to wrap your child components and elements in place of <div> or <span> tags. Like so,
render(){
return(
<Fragment>
<h2>Heading</h2>
<ChildA />
</Fragment>
);
}
or
render(){
return(
<React.Fragment>
<h2>Heading</h2>
<ChildA />
</React.Fragment>
);
}
As a shortcut, you can also use empty tags <></> to indicate a fragment. Like so,
render(){
return(
<>
<h2>Heading</h2>
<ChildA />
</>
);
}
If you dont want to put extra divs & spans,
<></> will be nice pick for you
React does the replacement of React.Fragment component there
<></> == <React.Fragment></React.Fragment>
I'm currently switching my web app to react. The old one is located here.
What I'm trying to do is: when an user enter a player's username into the text field and submit, the app would redirect to the corresponding route (/:username), and the text field is cleared.
In the react version, this is what I'm doing currently:
https://github.com/AVAVT/g0tstats-react/blob/master/src/components/SideBar/SearchBox.js
submit(event){
...
this.setState({
redirect : true
});
...
}
And
render(){
...
{
this.state.redirect && (
<Redirect to={`/${this.state.username}`} push />
)
}
}
Which kinda work. But there are 2 things I don't like about it:
I'm rendering an element in order to redirect. It feels stupid and roundabout. It stinks of potential bug in the future.
I'm stuck with the text field not cleared. Because I if I set state.username to null the <Redirect /> component will not redirect correctly. In fact I don't have any precise control over when the redirection occur (unless I do it in another roundabout way).
I have searched for alternative, but couldn't find one. withRouter doesn't work because <SearchBox /> is not a <Route /> and doesn't receive the history props.
So how can I say "redirect me to that place NOW" in react-router v4?
Here is an example that shows when using the withRouter HOC, the routing props get injected to components even if they are not routed to.
Here is my App.js
class App extends Component {
render() {
return (
<div className="App">
<BrowserRouter>
<div>
<Route path='/test' component={Sample} />
<Sibling />
</div>
</BrowserRouter >
</div>
);
}
}
export default App;
Here is my Sample.js. This is like an example container that is rendering a child.
export default class Sample extends React.Component {
render() {
return (
<div>
<span>{this.props.location.pathname}</span>
<br />
<Nested />
</div>
)
}
}
This component can display information about the current route even without the withRouter HOC since it is being routed to.
Here is my Nested.js.
class Nested extends React.Component {
render() {
return (
<div>
<span>I am nested {this.props.location.pathname}</span>
</div>
)
}
}
export default withRouter(Nested);
My nested component needs the withRouter HOC in order to display the current route.
Finally here is my Sibling.js. (This is like your example where <SearchBox /> is a sibling.)
class Sibling extends React.Component {
render() {
return (
<span>{this.props.location.pathname}</span>
)
}
}
export default withRouter(Sibling);
Here all that is needed is to make sure that the sibling is nested within the router as you can see in my App.js, and then using the withRouter HOC it can display the current pathname.
To clarify: If a component can access the current pathname then it can also change the routes programmatically by doing this. this.props.history.push(some path).
I hope this helps.
Today I have started learning ReactJS and after an hour faced with the problem..
I want to insert a component which has two rows inside a div on the page.A simplified example of what I am doing below.
I have an html:
<html>
..
<div id="component-placeholder"></div>
..
</html>
Render function like this:
...
render: function() {
return(
<div className="DeadSimpleComponent">
<div className="DeadSimpleComponent__time">10:23:12</div >
<div className="DeadSimpleComponent__date">MONDAY, 2 MARCH 2015</div>
</div>
)
}
....
And below I am calling render:
ReactDOM.render(<DeadSimpleComponent/>, document.getElementById('component-placeholder'));
Generated HTML looks like this:
<html>
..
<div id="component-placeholder">
<div class="DeadSimpleComponent">
<div class="DeadSimpleComponent__time">10:23:12</div>
<div class="DeadSimpleComponent__date">MONDAY, 2 MARCH 2015</div>
</div>
</div>
..
</html>
The problem that I am not a very happy that React forcing me to wrap all in a div "DeadSimpleComponent". What is the best and simple workaround for it, without explicit DOM manipulations?
UPDATE 7/28/2017: Maintainers of React added that possibility in React 16 Beta 1
Since React 16.2, you can do this:
render() {
return (
<>
<ChildA />
<ChildB />
<ChildC />
</>
);
}
This requirement was removed in React version (16.0), so now you are able to avoid that wrapper.
You can use React.Fragment to render a list of elements without creating a parent node, official example:
render() {
return (
<React.Fragment>
<ChildA />
<ChildB />
<ChildC />
</React.Fragment>
);
}
More here: Fragments
Update 2017-12-05:
React v16.2.0 now fully supports rendering of fragments with improved support for returning multiple children from a components render method without specifying keys in children:
render() {
return (
<>
<ChildA />
<ChildB />
<ChildC />
</>
);
}
If you are using a React version prior to v16.2.0, it is also possible to use <React.Fragment>...</React.Fragment> instead:
render() {
return (
<React.Fragment>
<ChildA />
<ChildB />
<ChildC />
</React.Fragment>
);
}
Original:
React v16.0 introduced returning an array of elements in render method without wrapping it in a div: https://reactjs.org/blog/2017/09/26/react-v16.0.html
render() {
// No need to wrap list items in an extra element!
return [
// Don't forget the keys :)
<li key="A">First item</li>,
<li key="B">Second item</li>,
<li key="C">Third item</li>,
];
}
At the moment, a key is required for each element to avoid the key warning but this could be changed in future releases:
In the future, we’ll likely add a special fragment syntax to JSX that
doesn’t require keys.
You can use:
render(){
return (
<React.Fragment>
<div>Some data</div>
<div>Som other data</div>
</React.Fragment>
)
}
For further details refer to this documentation.
Use [], instead of ()'s to wrap the entire return.
render: function() {
return[
<div className="DeadSimpleComponent__time">10:23:12</div >
<div className="DeadSimpleComponent__date">MONDAY, 2 MARCH 2015</div>
]
}
I created a component to wrap child components without a DIV. It's called a shadow wrapper: https://www.npmjs.com/package/react-shadow-wrapper
This is still required, BUT React now make sure to create elements without creating an additional DOM element.
The extra wrapping needed (normally with a parent div) because Reacts createElement method require a type parameter which is either a tag name string (such as 'div' or 'span'), a React component type (a class or a function). But this was before they introduce React Fragment.
Refer this NEW api doc for createElement
React.createElement : Create and return a new React element of the given type. The type argument can be either a tag name string (such as 'div' or 'span'), a React component type (a class or a function), or a React fragment type.
here is the official example, Refer React.Fragment.
render() {
return (
<React.Fragment>
Some text.
<h2>A heading</h2>
</React.Fragment>
);
}
I know this question has been answered, you can of course use React.Fragment which doesn't create a node but let's you group stuff like a div.
Additionally if you want to have fun you can implement (and learn lots of things) a React mode that removes the extra div's and for this I really want to share a great video on how you can do it on the react code base itself.
https://www.youtube.com/watch?v=aS41Y_eyNrU
This is of course not something that you would do in practice but it's a good learning opportunity.
You won't be able to get rid of that div element. React.render() needs to return one valid DOM node.
Here is one way to render "transculent" components:
import React from 'react'
const Show = (props) => {
if (props.if || false) {
return (<React.Fragment>{props.children}</React.Fragment>)
}
return '';
};
----
<Show if={yomama.so.biq}>
<img src="https://yomama.so.biq">
<h3>Yoamama</h3>
<Show>
There is workaround too. The below block code generates fragment without the need of React.Fragment.
return [1,2,3].map(i=>{
if(i===1) return <div key={i}>First item</div>
if(i===2) return <div key={i}>Second item</div>
return <div key={i}>Third item</div>
})
How to customize nested components?
I'm building React Native app with Redux.
I have three screens in my app that render list of users.
Follower/Following should show FollowButton:
<FollowersContainer>
<UserList onFollow={func} onUnfollow={func} users={[...]}>
<UserCard user={user} onFollow={func} onUnfollow={func}>
<FollowButton onFollow={func} onUnfollow={func} isFollowing={bool} userId={string} />
</UserCard>
</UserList>
</FollowersContainer>
Ask question screen should show AskButton:
<AskQuestionContainer>
<UserList onAsk={func} users={[...]}>
<UserCard user={user} onAsk={func}>
<AskButton onPress={onAsk} />
</UserCard>
</UserList>
</AskQuestionContainer>
Search Results should not show any button
<SearchResultsContainer>
<UserList users={[...]}>
<UserCard user={user} />
</UserList>
</SearchResultsContainer>
As you can see, all three screens uses UserList and UserCard components.
Currently UserList and UserCard needs to know about onFollow onUnfollow and onAsk actions and how to pass them around.
This can get complicated and not very flexible.
Ideally I want to do something like:
<UserList
rowComponent={
<UserCard button={<FollowButton />} />
}
/>
But how do I pass the actions from the top level component into the actual button? and How do I know which actions to pass?
I could use connect on the actual buttons to pass them the actions directly but I prefer these components stay pure and flexible.
Any suggestion on how to solve it in a clean way?
Thanks,
Ran.
You can pass components as a prop.
render() {
var passedButton = (<FollowButtton />);
var row = (<UserCard button={passedButton} />);
return (
<UserList rowComponent={row}/>
);
};