I am using React and bootstrap 4 to generate a collapsible div. Inside this div I have another React component, like this:
ComponentA
<a name={name}
className={'btn btn-primary'}
data-toggle={'collapse'}
href={'#collapseId'}
role={'button'} aria-expanded={'false'}
aria-controls={'collapseId'}>
collapse
</a>
<div id='collapseId'>
<ComponentB/>
</div>
This works correctly, but when I render ComponentA multiple times (I need to render it more than 20 times) I get performance issues, because ComponentB includes many divs and buttons.
So what I want to do is to render conditionally ComponentB but keep bootstrap's collapse transitions.
Now, if I want to conditionally render, I do this:
constructor(props){
super(props);
this.state={collapsed=true}
}
conditionalRender(e){
this.setState(prevState => this.state.collapsed = !prevState.collapsed)
}
And then in the render function:
<a name={name}
className={'btn btn-primary'}
data-toggle={'collapse'}
href={'#collapseId'}
role={'button'} aria-expanded={'false'}
aria-controls={'collapseId'}
onClick={(e)=>this.conditionalRender(e)}>
collapse
</a>
<div id='collapseId'>
{!this.state.collapsed &&
<ComponentB/>
}
</div>
And it works, BUT the transition is laggy, not fluid and doesn't look good.
Is there a way to delay the transition of the collapsed transition for this to work and be fluid? I've seen some overrides to css transition, but again, not fluid.
Another valid option would be to use the callback function of setState to execute the default anchor's functionality but I don't know how to.
bootstrap 4.1
react 16.4.2
Related
I'm in a learning phase of react and I've been trying to nest style of parent in component in child component via class in react.js. How to do it?
What I've tried until now:
function Card(props) {
const classes = 'card' + props.className;
return (
<div className={classes}>
{props.children}
</div>
)
}
export default Card
I applied style on class 'card' in a CSS file.
Parent component JS code:
import Card from './UI/Card';
function ExpenseItem(props){
return (
<Card className="expense-item">
<ExpenseDate date={props.date} />
<div className="expense-item__description">
<h2>{props.title}</h2>
<div className="expense-item__price">{`₹ ${props.amount}`}</div>
</div>
</Card>
)
}
Now, there are various classes in parent component that are styled accordingly. And I'd like to nest those classes in child component for those style to work.
You can see in the code the way I tried to nest the classes, but it isn't working.
const classes = 'card' + props.className;
What am I doing wrong? And how should I correct it?
You missed a space after the card class name, otherwise i don't see any other issues in your code. Try below, hope it works
const classes = 'card ' + props.className;
Just one note, this will make your components dependent on each other. One of best things about React is that it allows you to have separation of concerns. So Card component is doing Card component staff, displaying some information and needs not be dependent on a parent in this case ExpenseItem.
One way to do it is to use styled-components.
I'm making a simple portfolio page and for the same, I have a few icons I want to render for which I have used Material UI icons
Now I added the same custom styling to them and since I'm new to styled-components I did it as follows
const iconsArray = [GitHubIcon, LinkedInIcon, CallIcon];
const styledIcons = iconsArray.map(
(item) => styled(item)`
//other styles
:hover {
cursor: pointer;
}
`
);
the iconsArray above is made from direct imports from Material UI icons
Now I want to render the icons as
{styledIcons.map(styledIcon=>(
<styledIcon>
<a href={correspondingLink}>
</a>
</styledIcon>
)}
This won't work for obvious reasons but I can't access the component even using styledIcon.component like we could for normal react components. Any suggestions on how to achieve this?
Hello I have Dots and Carousel component:
<Dots :carousel="$refs.carousel" />
<div>
some data
</div>
<carousel
ref="carousel"
:per-page="4"
:autoplay="true"
:autoplay-timeout="3000"
:mouse-drag="false"
>
....
</carousel>
When I try pass to prop on Dots component, I get undefined in prop data, why? I need Dots component to be before the Carousel component. This is important. I think, that this is reason why does not it work. If I put Dots component after carousel component, then working good.
In Dots component I have:
export default {
name: 'Dots',
props: ['carousel']
}
In mounted when I try call console.log(this.carousel), I get undifined. But I need get a component data of Carousel. How I can do it?
Sandbox test: https://codesandbox.io/s/flamboyant-monad-5bhjz?file=/src/components/Test.vue
If you only need to have Dot before your Carousel for aesthetic reason you can reorder your template (eg: https://developer.mozilla.org/fr/docs/Web/CSS/order).
You will be able to put you Dot component after Carousel to get its ref, but it will be show before.
I'm having trouble finding relevant documentation on how to remove UI components when using react. For example, there's a login form. The user clicks submit and now the form should be removed from the screen. How do I do this?
I've found unmountComponentAtNode, but that can only be invoked at the parent level. Am I supposed to have a parent node that is aware of all child state and loads them conditionally? Should all children have an "isHidden" attribute which renders the dom as hidden if true?
This must be basic but I don't see this in the react js tutorials. I found this stackoverflow post (react.js: removing a component) is this really the pattern? It kind of makes sense but it means that a large app will likely have an extremely complex Application parent class that manages maps of application state based on configuration.
It seems like i need to start defining application state as named maps. For example:
BaseApp: showHeader=true;showContent=true;
LoginState: showBaseApp=true;showLoginForm=true;
LoggedInState: showBaseApp=true;showFeed=true;
At any moment we would have to update all state maps and call the base class render method...
In my opinion your question isn't about removing component but about showing the right component. And yes - it can be done with a component state but with Flux/Redux store/reducer as well.
In your example with a login form after click on "Submit" we can change local state for the component and show another text like "The request was sent blah-blah-blah" or another component.
But you can do this by extracting component's local state to a store/reducer and it'll be work better in relatively big app. Nevertheless, it's really up to you where you want to store state.
I like to use a hide prop like so.
class AppCtrlRender extends React.Component {
render() {
let page = this.state.appState.currentPage;
let hideAbout = (page != 'about');
let hideHome = (page != 'home');
return (
<div id='AppCtrlSty' style={AppCtrlSty}>
<div id='allPageSty' style={allPageSty}>
<AboutPage hide={hideAbout} />
<HomePage hide={hideHome} />
</div>
</div>
);
}
}
export default class AboutPage extends React.Component {
render() {
if (this.props.hide) return null;
let aTime = (new Cache()).time.toString();
return (
<div style={AboutPageSty}>
React 0.14 ReFlux used for app state. This is the About Page.
<NavMenu /><br/><br/>
{aTime}
</div>
);
}
}
I've been hiding/showing react components by not rendering them, for example:
render: function() {
var partial;
if (this.state.currentPage === 'home') {
partial = <Home />;
} else if (this.state.currentPage === 'bio') {
partial = <Bio />;
} else {
partial = <h1>Not found</h1>
}
return (
<div>
<div>I am a menu that stays here</div>
Home Bio
{partial}
</div>
);
}
but just say that the <Bio/> component has lots of internal state. Everytime I recreate the component, it loses it's internal state, and resets to it's original state.
I know of course that I could store the data for it somewhere, and pass it in via props or just globally access it, but this data doesn't really need to live outside of the component. I could also hide/show components using CSS (display:none), but I'd prefer to hide/show them as above.
What's the best practice here?
EDIT: Maybe a better way to state the problem is to use an example:
Ignore React, and assume you were just using a desktop app that had a configuration dialog with a Tab component called A, which has 2 tabs, named 1 and 2.
Say that tab A.1 has an email text field and you fill in your email address. Then you click on Tab A.2 for a second, then click back to Tab A.1. What's happened? Your email address wouldn't be there anymore, it would've been reset to nothing because the internal state wasn't stored anywhere.
Internalizing the state works as suggested in one of the answers below, but only for the component and it's immediate children. If you had components arbitrarily nested in other components, say Tabs in Tabs in Tabs, the only way for them to keep their internal state around is to either externalize it somewhere, or use the display:none approach which actually keeps all the child components around at all times.
It just seems to me that this type of data isn't data you want dirtying up your app state... or even want to even have to think about. It seems like data you should be able to control at a parent component level, and choose to either keep or discard, without using the display:none approach and without concerning yourself with details on how it's stored.
One option would be to move the conditional inside the component itself:
Bio = React.createClass({
render: function() {
if(this.props.show) {
return <p>bio comp</p>
} else {
return null;
}
}
});
<Bio show={isBioPage} />
Whether this is "best practise" or not probably depends on the exact situation.
Unfortunately, style={{display: 'none'}} trick only works on normal DOM element, not React component. I have to wrap component inside a div. So I don't have to cascade the state to subcomponent.
<div className="content">
<div className={this.state.curTab == 'securities' ? 'active' : ''}>
<Securities />
</div>
<div className={this.state.curTab == 'plugins' ? 'active' : ''}>
<Plugins />
</div>
</div>
Looks like official documentation suggests hiding stateful children with style={{display: 'none'}}
The fundamental problem here is that in React you're only allowed to mount component to its parent, which is not always the desired behavior. But how to address this issue?
I propose the solution, addressed to fix this issue. More detailed problem definition, src and examples can be found here: https://github.com/fckt/react-layer-stack#rationale
Rationale
react/react-dom comes comes with 2 basic assumptions/ideas:
every UI is hierarchical naturally. This why we have the idea of components which wrap each other
react-dom mounts (physically) child component to its parent DOM node by default
The problem is that sometimes the second property isn't what you want
in your case. Sometimes you want to mount your component into
different physical DOM node and hold logical connection between
parent and child at the same time.
Canonical example is Tooltip-like component: at some point of
development process you could find that you need to add some
description for your UI element: it'll render in fixed layer and
should know its coordinates (which are that UI element coord or
mouse coords) and at the same time it needs information whether it
needs to be shown right now or not, its content and some context from
parent components. This example shows that sometimes logical hierarchy
isn't match with the physical DOM hierarchy.
Take a look at https://github.com/fckt/react-layer-stack/blob/master/README.md#real-world-usage-example to see the concrete example which is answer to your question (take a look at the "use" property):
import { Layer, LayerContext } from 'react-layer-stack'
// ... for each `object` in array of `objects`
const modalId = 'DeleteObjectConfirmation' + objects[rowIndex].id
return (
<Cell {...props}>
// the layer definition. The content will show up in the LayerStackMountPoint when `show(modalId)` be fired in LayerContext
<Layer use={[objects[rowIndex], rowIndex]} id={modalId}> {({
hideMe, // alias for `hide(modalId)`
index } // useful to know to set zIndex, for example
, e) => // access to the arguments (click event data in this example)
<Modal onClick={ hideMe } zIndex={(index + 1) * 1000}>
<ConfirmationDialog
title={ 'Delete' }
message={ "You're about to delete to " + '"' + objects[rowIndex].name + '"' }
confirmButton={ <Button type="primary">DELETE</Button> }
onConfirm={ this.handleDeleteObject.bind(this, objects[rowIndex].name, hideMe) } // hide after confirmation
close={ hideMe } />
</Modal> }
</Layer>
// this is the toggle for Layer with `id === modalId` can be defined everywhere in the components tree
<LayerContext id={ modalId }> {({showMe}) => // showMe is alias for `show(modalId)`
<div style={styles.iconOverlay} onClick={ (e) => showMe(e) }> // additional arguments can be passed (like event)
<Icon type="trash" />
</div> }
</LayerContext>
</Cell>)
// ...