I've just started learning React and have a question.
I want to do the following:
If a user clicks on a paragraph I want to change the element to an input field that has the contents of the paragraph prefilled.
(The end goal is direct editing if the user has certain privileges)
I'm come this far but am totally at a loss.
var AppHeader = React.createClass({
editSlogan : function(){
return (
<input type="text" value={this.props.slogan} onChange={this.saveEdit}/>
)
},
saveEdit : function(){
// ajax to server
},
render: function(){
return (
<header>
<div className="container-fluid">
<div className="row">
<div className="col-md-12">
<h1>{this.props.name}</h1>
<p onClick={this.editSlogan}>{this.props.slogan}</p>
</div>
</div>
</div>
</header>
);
}
});
How can I override the render from the editSlogan function?
If I understand your questions correctly, you want to render a different element in case of an "onClick" event.
This is a great use case for react states.
Take the following example
React.createClass({
getInitialState : function() {
return { showMe : false };
},
onClick : function() {
this.setState({ showMe : true} );
},
render : function() {
if(this.state.showMe) {
return (<div> one div </div>);
} else {
return (<a onClick={this.onClick}> press me </a>);
}
}
})
This will change the components state, and makes React render the div instead of the a-tag. When a components state is altered(using the setState method), React calculates if it needs to rerender itself, and in that case, which parts of the component it needs to rerender.
More about states
https://facebook.github.io/react/docs/interactivity-and-dynamic-uis.html
You can solve it a little bit more clear way:
class EditableLabel extends React.Component {
constructor(props) {
super(props);
this.state = {
text: props.value,
editing: false
};
this.initEditor();
this.edit = this.edit.bind(this);
this.save = this.save.bind(this);
}
initEditor() {
this.editor = <input type="text" defaultValue={this.state.text} onKeyPress={(event) => {
const key = event.which || event.keyCode;
if (key === 13) { //enter key
this.save(event.target.value)
}
}} autoFocus={true}/>;
}
edit() {
this.setState({
text: this.state.text,
editing: true
})
};
save(value) {
this.setState({
text: value,
editing: false
})
};
componentDidUpdate() {
this.initEditor();
}
render() {
return this.state.editing ?
this.editor
: <p onClick={this.edit}>{this.state.text}</p>
}
}
//and use it like <EditableLabel value={"any external value"}/>;
Related
Currently I have a component which render a modal component.
constructor(props) {
super(props);
this.state = {
fieldId: "",
rating: -1,
description: "",
showModal: false //This is what checks if the modal should or shouldnt be rendered
};
console.log(props) //week number, beginning with 0
this.showModal = this.showModal.bind(this);
this.closeModal = this.closeModal.bind(this);
}
showModal() {
console.log("showmodal state before any click")
console.log(this.state.showModal) //false
this.setState({
showModal: true
}, () => {
console.log("clicked show modal")
console.log(this.state.showModal) //true
});
}
closeModal() {
this.setState({
showModal: false
}, () => {
console.log("clicked closeModal")
console.log(this.state.showModal) //true <------ !WHY IS THIS TRUE??
});
}
render() {
var weekId = this.props.weekId;
//current week, round up
//lived weeks, round down
//total weeks, round up
if (weekId < this.props.weeksToRegisterDate) {
return <div id={weekId} className="cube-lived"></div>
} else if (weekId == this.props.currentWeek) {
return <div id={weekId} title={weekId} className="cube green" onClick={this.showModal}>
<CalendarFieldModal show={this.state.showModal} close={this.closeModal} />
</div>
} else {
return <div id={weekId} title={weekId} className="cube white" onClick={this.showModal}>
<CalendarFieldModal show={this.state.showModal} close={this.closeModal} />
</div>
}
}
}
Basically if I click the cube it will render a modal Component, which looks like this.
import React from 'react'
import './CalendarFieldModal.css'
class CalendarFieldModal extends React.Component {
constructor(props) {
super(props);
this.state = {
};
}
render() {
if (!this.props.show) {
return null;
}
// return <div className="cube-to-spawn"></div>
return <div id="open-modal" class="modal-window">
<div>
<a href="#" title="Close" class="modal-close" onClick={this.props.close}>Close</a> //this triggers the function and should close the modal
<h1>Voilà!</h1>
<div>A CSS-only modal based on the :target pseudo-class. Hope you find it helpful.</div>
<div><small>Check out</small></div>
</div>
</div>
}
}
export default CalendarFieldModal;
Now in the late component I have a close button, which If i click, i can see the closeModal() function triggering and logging the console.log , so I suppose that the state is changing to. But still it doesnt close the modal. So i dont understand the issue
EDIT: This is how it looks https://codesandbox.io/embed/quirky-ardinghelli-8fgtx?fontsize=14&hidenavigation=1&theme=dark you must open the preview in a new windows, or else the modal wont load
Refactor it a bit:
if (weekId < this.props.weeksToRegisterDate) {
return <div id={weekId} className="cube-lived"></div>
} else {
const currentStyle = (weekId == this.props.currentWeek) ? "green" : "white";
return <div id={weekId} title={weekId}
className=`cube ${currentStyle}`
{...(!this.state.showModal && { onClick: this.showModal })}
>
<CalendarFieldModal show={this.state.showModal} close={this.closeModal} />
</div>
}
Explanation
Outer <div/> was not this.state.showModal changes aware - no props change, not rerendered - no matter inner object's props changed and should be rerendered.
I have three buttons that when clicking show and individual div but this is done in reactjs
import React, { Component } from 'react';
export class ModeExtended extends Component {
constructor() {
super();
this.busButton = this.busButton.bind(this);
this.trainButton = this.trainButton.bind(this);
this.tramButton = this.tramButton.bind(this);
this.state = {
isHidden: false,
}
}
busButton(){
console.log('Bus Button Was Pressed');
this.setState((prevState) => {
return{
isHidden: !prevState.isHidden
};
});
}
trainButton(){
console.log('Train Button Was Pressed');
this.setState((prevState) => {
return{
isHidden: !prevState.isHidden
};
});
}
tramButton(){
console.log('Tram Button Was Pressed');
this.setState((prevState) => {
return{
isHidden: !prevState.isHidden
};
});
}
render() {
return (
<div>
<h5>Mode Extended</h5>
<button onClick={this.busButton}>Bus</button>
<button onClick={this.trainButton}>Train</button>
<button onClick={this.tramButton}>Tram</button>
{this.state.isHidden && (
<div>
<h6>You can show Bus Data Now....</h6>
</div>
)}
{this.state.isHidden && (
<div>
<h6>You can show Train Data Now....</h6>
</div>
)}
{this.state.isHidden && (
<div>
<h6>You can show Tram Data Now....</h6>
</div>
)}
</div>
)
}
}
export default ModeExtended
When I click any of the buttons it shows all bus, tram and train data - how do I get them to just show one thing at a time and making sure that the other states are closed. I am really missing something here and need a pointer or two or three…
How can I add an ID to make each button open separate from each other and when one is clicked how can I close the rest of the divs - or open state, I am so lost here. Please help me out.
Cheers as always!
Here is a REPL of my code:
You need to have 3 different isHidden properties to control your divs. You can do it like this:
this.state = {
isHiddenBus: false,
isHiddenTrain: false,
isHiddenTram: false,
}
and then in your render like this:
{this.state.isHiddenBus && (
<div>
<h6>You can show Bus Data Now....</h6>
</div>
)}
{this.state.isHiddenTrain && (
<div>
<h6>You can show Train Data Now....</h6>
</div>
)}
{this.state.isHiddenTram && (
<div>
<h6>You can show Tram Data Now....</h6>
</div>
)}
also your buttons have to change to state accordingly to this.
busButton(){
console.log('Bus Button Was Pressed');
this.setState((prevState) => {
return{
isHiddenBus: !prevState.isHiddenBus
isHiddenTram: false
isHiddenTrain: false
};
});
}
trainButton(){
console.log('Train Button Was Pressed');
this.setState((prevState) => {
return{
isHiddenTrain: !prevState.isHiddenTrain
isHiddenBus: false
isHiddenTram: false
};
});
}
tramButton(){
console.log('Tram Button Was Pressed');
this.setState((prevState) => {
return{
isHiddenTram: !prevState.isHiddenTram
isHiddenTrain: false
isHiddenBus: false
};
});
}
you can do somthing like this:
import React, { Component } from 'react';
export class ModeExtended extends Component {
constructor() {
super();
this.state = {
curDivIndex:0,//currently visible div index
// isHidden: false,
}
}
renderDiv=()=>{
switch(this.state.curDivIndex){
case 1:return <div> <h6>You can show Bus Data Now....</h6> </div>
case 2:return <div> <h6>You can show Train Data Now....</h6> </div>
case 3:return <div> <h6>You can show Tram Data Now....</h6> </div>
}
return null
}
setVisibleDiv=(index)=>{
this.setState({curDivIndex:index})
}
render() {
return (
<div>
<h5>Mode Extended</h5>
<button onClick={()=>{this.setVisibleDiv(1)} }>Bus</button>
<button onClick={()=>{this.setVisibleDiv(2)}}>Train</button>
<button onClick={()=>{this.setVisibleDiv(3)}}>Tram</button>
{this.renderDiv()}
</div>
)
}
}
export default ModeExtended
EDIT
you want to have three different buttons, on click of each certain div
needs to be visible.
you can achieve this by maintaining the index of currently visible div.
when user clicks any button you have to set the index of div to be visible
which in the above code is achieved by using setVisibleDiv(index) call.
and you can at rendering time use curDivIndex to decide visible div.
Or you can achieve this by declaring state properties for all case:
this.state = {
hiddenBus: false,
hiddenTrain: false,
hiddenTram: false,
}
providing a name attribute to your buttons like so:
<button name="hiddenBus" onClick={toggleDisplay}>Bus</button>
<button name="hiddenTrain" onClick={toggleDisplay}>Train</button>
<button name="hiddenBus" onClick={toggleDisplay}>Tram</button>
then by defining the toggleDisplay function to toggle their display:
toggleDisplay = (event) => {
event.preventDefault(); // default behavior of a clicked button is to send a form so let's prevent this
const { name } = event.target; // find the clicked button name value
this.setState((prevState => ({
[name]: !prevState[name],
}));
}
Setting[name] enables us to target the state prop via the nameattribute value and update it based on the previous state.
Try this
import React, { Component } from "react";
export default class Create extends Component {
constructor(props) {
super(props);
this.state = {
currentBtn: null
};
}
clickedButton = e => {
this.setState({ currentBtn: e.target.id });
};
showDivElem = () => {
const { currentBtn } = this.state;
switch (currentBtn) {
case "A":
return <div>A</div>;
break;
case "B":
return <div>B</div>;
break;
case "C":
return <div>C</div>;
break;
default:
return <div>ABC</div>;
break;
}
};
render() {
console.log(this.state.currentBtn);
return (
<div>
<button id="A" onClick={e => this.clickedButton(e)}>
A
</button>
<button id="B" onClick={e => this.clickedButton(e)}>
B
</button>
<button id="C" onClick={e => this.clickedButton(e)}>
C
</button>
{this.showDivElem()}
</div>
);
}
}
The function is getting the value of a button click as props. Data is mapped through to compare that button value to a key in the Data JSON called 'classes'. I am getting all the data correctly. All my console.logs are returning correct values. But for some reason, I cannot render anything.
I've tried to add two return statements. It is not even rendering the p tag with the word 'TEST'. Am I missing something? I have included a Code Sandbox: https://codesandbox.io/s/react-example-8xxih
When I click on the Math button, for example, I want to show the two teachers who teach Math as two bubbles below the buttons.
All the data is loading. Just having an issue with rendering it.
function ShowBubbles(props){
console.log('VALUE', props.target.value)
return (
<div id='bubbles-container'>
<p>TEST</p>
{Data.map((item,index) =>{
if(props.target.value == (Data[index].classes)){
return (
<Bubble key={index} nodeName={Data[index].name}>{Data[index].name}
</Bubble>
)
}
})}
</div>
)
}
Sandbox Link: https://codesandbox.io/embed/react-example-m1880
import React, {Component} from 'react';
import ReactDOM from 'react-dom';
const circleStyle = {
width: 100,
height: 100,
borderRadius: 50,
fontSize: 30,
color: "blue"
};
const Data = [
{
classes: ["Math"],
name: "Mr.Rockow",
id: "135"
},
{
classes: ["English"],
name: "Mrs.Nicastro",
id: "358"
},
{
classes: ["Chemistry"],
name: "Mr.Bloomberg",
id: "405"
},
{
classes: ["Math"],
name: "Mr.Jennings",
id: "293"
}
];
const Bubble = item => {
let {name} = item.children.singleItem;
return (
<div style={circleStyle} onClick={()=>{console.log(name)}}>
<p>{item.children.singleItem.name}</p>
</div>
);
};
function ShowBubbles(props) {
var final = [];
Data.map((item, index) => {
if (props.target.value == Data[index].classes) {
final.push(Data[index])
}
})
return final;
}
function DisplayBubbles(singleItem) {
return <Bubble>{singleItem}</Bubble>
}
class Sidebar extends Component {
constructor(props) {
super(props);
this.state = {
json: [],
classesArray: [],
displayBubble: true
};
this.showNode = this.showNode.bind(this);
}
componentDidMount() {
const newArray = [];
Data.map((item, index) => {
let classPlaceholder = Data[index].classes.toString();
if (newArray.indexOf(classPlaceholder) == -1) {
newArray.push(classPlaceholder);
}
// console.log('newArray', newArray)
});
this.setState({
json: Data,
classesArray: newArray
});
}
showNode(props) {
this.setState({
displayBubble: true
});
if (this.state.displayBubble === true) {
var output = ShowBubbles(props);
this.setState({output})
}
}
render() {
return (
<div>
{/* {this.state.displayBubble ? <ShowBubbles/> : ''} */}
<div id="sidebar-container">
<h1 className="sidebar-title">Classes At School</h1>
<h3>Classes To Search</h3>
{this.state.classesArray.map((item, index) => {
return (
<button
onClick={this.showNode}
className="btn-sidebar"
key={index}
value={this.state.classesArray[index]}
>
{this.state.classesArray[index]}
</button>
);
})}
</div>
{this.state.output && this.state.output.map(item=><DisplayBubbles singleItem={item}/>)}
</div>
);
}
}
ReactDOM.render(<Sidebar />, document.getElementById("root"));
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.0.0/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.0.0/umd/react-dom.production.min.js"></script>
<div id="root"></div>
The issue here is ShowBubbles is not being rendered into the DOM, instead (according the sandbox), ShowBubbles (a React component) is being directly called in onClick button handlers. While you can technically do this, calling a component from a function will result in JSX, essentially, and you would need to manually insert this into the DOM.
Taking this approach is not very React-y, and there is usually a simpler way to approach this. One such approach would be to call the ShowBubbles directly from another React component, e.g. after your buttons using something like:
<ShowBubbles property1={prop1Value} <etc...> />
There are some other issues with the code (at least from the sandbox) that you will need to work out, but this will at least help get you moving in the right direction.
I am tring to show todo list with load more option. I am appling limit.Limit is apply to list.But when i add loadmore()function. then i get error this.state.limit is null Wher i am wrong.Any one can suggest me.
here is my code
todoList.jsx
var TodoList=React.createClass({
render:function(){
var {todos}=this.props;
var limit = 5;
function onLoadMore() {
this.setState({
limit: this.state.limit + 5
});
}
var renderTodos=()=>{
return todos.slice(0,this.state.limit).map((todo)=>{
return(
<Todo key={todo.todo_id}{...todo} onToggle={this.props.onToggle}/>
);
});
};
return(
<div>
{renderTodos()}
<a href="#" onClick={this.onLoadMore}>Load</a>
</div>
)
}
});
module.exports=TodoList;
Changes:
1. First define the limit in state variable by using getInitialState method, you didn't define the limit, that's why this.state.limit is null.
2. Define all the functions outside of the render method.
3. Arrow function with renderTodos is not required.
4. Use this keyword to call the renderTodos method like this:
{this.renderTodos()}
Write it like this:
var TodoList=React.createClass({
getInitialState: function(){
return {
limit: 5
}
},
onLoadMore() {
this.setState({
limit: this.state.limit + 5
});
},
renderTodos: function(){
return todos.slice(0,this.state.limit).map((todo)=>{
return(
<Todo key={todo.todo_id}{...todo} onToggle={this.props.onToggle}/>
);
});
};
render:function(){
var {todos} = this.props;
return(
<div>
{this.renderTodos()}
<a href="#" onClick={this.onLoadMore}>Load</a>
</div>
)
}
});
This is witout button click.
As you all know react components has a function componentDidMount() which gets called automatically when the template of that component is rendered into the DOM. And I have used the same function to add the event listener for scroll into our div iScroll.
The scrollTop property of the element will find the scroll position and add it with the clientHeight property.
Next, the if condition will check the addition of these two properties is greater or equal to the scroll-bar height or not. If the condition is true the loadMoreItems function will run.
class Layout extends React.Component {
constructor(props) {
super(props);
this.state = {
items: 10,
loadingState: false
};
}
componentDidMount() {
this.refs.iScroll.addEventListener("scroll", () => {
if (this.refs.iScroll.scrollTop + this.refs.iScroll.clientHeight >=this.refs.iScroll.scrollHeight){
this.loadMoreItems();
}
});
}
displayItems() {
var items = [];
for (var i = 0; i < this.state.items; i++) {
items.push(<li key={i}>Item {i}</li>);
}
return items;
}
loadMoreItems() {
this.setState({ loadingState: true });
setTimeout(() => {
this.setState({ items: this.state.items + 10, loadingState: false });
}, 3000);
}
render() {
return (
<div ref="iScroll" style={{ height: "200px", overflow: "auto" }}>
<ul>
{this.displayItems()}
</ul>
{this.state.loadingState ? <p className="loading"> loading More Items..</p> : ""}
</div>
);
}
}
This is example
I am working on a component where I need to display and hide a modal.
this is what I have in the render method in React
<div style={{visibility : this.state.displayModal}}>
<p>Pop up: Bet Behind Settings</p>
</div>
<button onClick={this._openModal}>CLICK</button>
and here is the function
_openModal = () => {
if (this.state.displayModal === 'hidden') {
this.setState({
displayModal : 'visible',
})
} else {
this.setState({
displayModal : 'hidden',
})
}
}
the main concern I have, is, how to set the state in a more elegant way, or this should be the way to do it ?
here the full code
constructor (props) {
super(props);
this.state = {
displayModal : 'hidden',
}
}
render () {
return (
<div style={{visibility : this.state.displayModal}}>
<p>Pop up: Bet Behind Settings</p>
</div>
<button onClick={this._openModal}>CLICK</button>
)
}
_openModal = () => {
if (this.state.displayModal === 'hidden') {
this.setState({
displayModal : 'visible',
})
} else {
this.setState({
displayModal : 'hidden',
})
}
}
so, what should be the way to this pop up in a React way.
I think it's a good way to do it. But it will be more concise if you make displayModel a boolean:
_toggleModal = () => this.setState({displayModal: !this.state.displayModal})
On a complex page using hidden will be a performance issue. Try something like this instead;
render() {
var returnIt;
if (this.state.hide) {
returnIt = null;
} else {
returnIt = (
<div style={{visibility : this.state.displayModal}}>
<p>Pop up: Bet Behind Settings</p>
</div>
<button onClick={this._openModal}>CLICK</button>
)
}
return (returnIt);
}
This is just a personal opinion, but I think a better UX would be that the button should only be used to open the modal; and the modal should be closed by either clicking the X in the modal (if there is) or when you click anywhere outside the modal.
That said if you definitely need the button to toggle between the 2 states, how about something like this?
constructor (props) {
super(props);
this.state = {
displayModal : false
}
}
render () {
return (
<div style={{visibility : this.state.displayModal === true ? 'visible' : 'hidden'}}>
<p>Pop up: Bet Behind Settings</p>
</div>
<button onClick={this._toggleModal}>CLICK</button>
)
}
_toggleModal = () => {
const current = this.state.displayModal;
this.setState({
displayModal : !current
});
}
Using https://github.com/fckt/react-layer-stack you can do like so:
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>)
// ...