I have one component in which I have one button and I am calling one node js service on that. I am getting a response back from that service and I want to pass that response on next component to display a data there. Below is my component which is doing a node js call.
import { FormGroup } from "react-bootstrap";
import "bootstrap/dist/css/bootstrap.css";
import axios from "axios";
export default class Abc extends React.Component {
constructor(props) {
super(props);
this.state = {
data: {}
}
this.handleClick = this.handleClick.bind(this);
}
handleClick = (e) => {
e.preventDefault();
axios.get(url)
.then(res => {
this.setState({
data: res.data// I need this variable to pass to next component Pqr where I can use it for display purpose.
})
this.props.history.push("/Pqr",{ response:res.data});
})
};
render() {
return (
<form >
<button className="btn btn-info btn-sm" onClick={this.handleClick} style={{ whitespace: 'nowrap' }} >
Launch
</button>
</form>
)
}
}
My Pqr component code is as below.
import React from "react";
export default class ModelLaunch extends React.Component {
constructor(props) {
super(props);
this.state = {
}
}
render() {
const state = this.props.location.state
return (
<h1>This page will display model Inputs : {state} </h1>
)
}
}
I have solved above problem with other way. Instead of calling a node js service on Abc component I am just redirecting it to new coponent and in new component's componentDidMount() method I am calling a node js service and storind a data in props. In this way I have my data on new copmonent. Below is my updated code in Abc component now.
import { FormGroup } from "react-bootstrap";
import "bootstrap/dist/css/bootstrap.css";
import axios from "axios";
export default class Abc extends React.Component {
constructor(props) {
super(props);
this.state = {
data: {}
}
this.handleClick = this.handleClick.bind(this);
}
handleClick = (e) => {
e.preventDefault();
this.props.history.push("/Pqr");
})
};
render() {
return (
<form >
<button className="btn btn-info btn-sm" onClick={this.handleClick} style={{ whitespace: 'nowrap' }} >
Launch
</button>
</form>
)
}
And in pqr coponent's code as below
import React from "react";
import axios from "axios";
export default class Pqr extends React.Component{
constructor(props)
{
super(props);
this.state = {
data :[]
}
}
componentDidMount(){
axios.get(url).then((res) => {
console.log("res****",res.data)
this.setState({
data:res.data
})
}).catch((err) =>{
console.log("err", err)
})
}
render()
{
return(
<h1>This page will display data</h1>
)
}
}
I see you're changing a route (using react-router?).
Remember that this.setState is async and specific for your component, when you call this.props.history.push('/Pqr'), maybe the this.state.data is not updated yet.
To share this data through different routes in the same react project, I actually know that you can:
Store it on window.localStorage and then get on the next route here have a tutorial
Use react contexts to share data between components (if you're not reloading the page)
Send data through routes with react-router, as explained here
If its not the case, and you just want to pass the property down or above the hierarchy tree, in addition to the comments above, maybe it can help:
As you probably know, react projects are composed of components that are put all together to work in a specific way. In the example below, there are two components (father and child)
import React from 'react';
// We can say that this component is "below" Father
function Child(props) {
return (
<button>
Hey, I'm a button!
</button>
);
}
// We can say that this component is "above" Child
function Father(props) {
return (
<div>
<Child />
</div>
);
}
I couldn't find in the provided code/question, one child component, maybe you forgot to write it?
If the response is "yes", I'll create a fictional component called... FictionalComponent (I'm a Genius!), and pass the data on state as a property named... data.
In order to pass this property, if its the case, you just need to update your render method to look like this:
render() {
return (
<form >
<button
className="btn btn-info btn-sm"
onClick={this.handleClick}
style={{ whitespace: 'nowrap' }}
>
Launch
<FictionalComponent data={this.state.data} />
</button>
</form>
)
}
This way, when this.state.data changes, the FictionalComponent will be re-rendered with the new data value.
But, maybe you want the reverse operation and you need to pass the this.state.data to the component above your Abc, listed there when the button is pressed.
To achieve it you need to have a "Father" component to your Abc, the "Father" component must provide an onDataChanged callback in order to capture the event. This callback will receive the data and handle it.
In this case, I'll create another component to be the component above your Abc. I'll name it... AboveAbcComponent, perfect!
...
class AboveAbcComponent extends React.Component {
constructor(props) {
this.state = {
dataFromChild: null
};
this.onDataChanged = this.onDataChanged.bind(this);
}
onDataChanged(dataReceived) {
console.log("Yey! It works!");
this.setState({ dataFromChild: dataReceived });
}
render() {// Just the passed props changes here
...
<Abc
onDataChanged={this.onDataChanged}
/>
...
}
}
export default class Abc extends React.Component {
constructor(props) { ... } // No changes here
handleClick = (e) => {
e.preventDefault();
axios.get(url)
.then(res => {
this.setState({
data: res.data
});
this.props.onDataChanged(res.data);
this.props.history.push("/Pqr"); // I really didn't understand Why this push is here... but ok
})
};
render() { ... } // No changes here
}
Hope it helps, have fun!
Related
I creating chat application by React.
In the chat application, there is a field for entering user_name and text.
I thought about managing those data with state, I made onNameChange and onTextChange events.
However, in the code I created, onTextChange was loaded but onNameChange was not loaded.
I know that onTextChange in the same file will be loaded.
Even though the files are different, I thought that data can be exchanged via props if the relationship is between parent and child.
I described the code with such a recognition, but I could not get the results I expected.
How can I pass data from LogoutStateForm.js to user_name in ChatForm.js via onNameChange?
ChatForm.js
import React,{Component} from 'react'
import firebase from 'firebase/app'
import { firebaseApp,firebaseDB } from '../firebase/firebase'
import LogoutStateForm from './LogoutStateForm'
const messagesRef = firebaseDB.ref('messages')
class ChatForm extends Component {
constructor(props){
super(props)
this.onNameChange = this.onNameChange.bind(this)
this.onTextChange = this.onTextChange.bind(this)
this.state = {
user: null,
user_name: "",
text: ""
}
}
componentDidMount(){
firebase.auth().onAuthStateChanged(user => {
this.setState({ user })
})
}
onNameChange(e) {
if (e.target.name == 'user_name') {
this.setState({
user_name: e.target.value
}),
console.log(this.state.user_name);
}
}
onTextChange(e) {
if (e.target.name == 'text') {
this.setState({
text: e.target.value
}),
console.log(this.state.text);
}
}
render(){
return(
<div id='Form'>
{this.state.user ?
<LogoutStateForm onClick={this.onNameChange} />:
null
}
//In order to switch display depending on login availability
<textarea name='text' onChange={this.onTextChange} placeholder='メッセージ'/>
</div>
)
}
}
export default ChatForm
LogoutStateForm.js
import React,{Component} from 'react'
import firebase from 'firebase/app'
class LogoutStateForm extends Component {
constructor(props){
super(props)
}
login() {
const provider = new firebase.auth.GoogleAuthProvider()
firebase.auth().signInWithPopup(provider)
}
componentDidMount(){
firebase.auth().onAuthStateChanged(user => {
this.setState({ user })
})
}
render(){
return(
<div className='logout'>
<input name='user_name' onChange={this.props.onNameChange} placeholder='名前'/>
<button onClick={this.login}>Goggle Login</button>
</div>
)
}
}
export default LogoutStateForm
Please lend me your wisdom.
Thank you.
First, in ChatForm.js, what you render LoginStateForm not LogoutStateForm.
Second, assuming it's supposed to be LogoutStateForm, at ChatForm component you pass onNameChange as onClick to LogoutStateForm.
However, you access the props as onNameChange in LogoutStateForm which is wrong. You should access it as the props name that you give, which is this.props.onClick.
Hope it helps.
In ChatForm.js, you are rendering wrong component, It should be LogoutStateForm.
Second you should access prop which you have passed.
ChatForm.js
<LogoutStateForm onNameChange={this.onNameChange} />
In LogoutStateForm.js
render(){
return(
<div className='logout'>
<input name='user_name' onChange={this.props.onNameChange} placeholder='名前'/>
<button onClick={this.login}>Goggle Login</button>
</div>
)
}
Also, define PropTypes in LogoutStateForm.js for verifying type check.
https://reactjs.org/docs/typechecking-with-proptypes.html
I have 2 components in my react application. On first time page load, the first component is supposed to make a query and display data(buttons) accordingly. The state of second component till now is empty. When the user clicks on any of the button, another request should be made to the sever and state of the second component should be changed and should be reflected on the web page.
These are my files..
Apps.js
import React, { Component } from 'react';
import './App.css';
import OrgList from "./orgList"
import OrgDetails from "./orgDetails"
class App extends Component {
render() {
return [
<OrgList/>,
<OrgDetails/>
];
}
}
export default App;
orgList.js
import React, { Component } from 'react'
import OrgDetails from "./orgDetails"
var posts =[]
class OrgList extends Component {
constructor(props){
super(props);
this.state={
mainpost: [],
devices:[],
}
}
componentDidMount(){
fetch(someURL)
.then(res => res.json())
.then(function (data){
for (let i = 0; i < 3; i++){
posts.push(data.orgs[i].name)
}
}).then(mainpost => this.setState({mainpost:posts}));
}
render() {
var token =new OrgDetails();
const postItems =this.state.mainpost.map((post) => (
console.log(post),
<button
data-tech={post}
key={post}
className="org-btn"
onClick={() => token.dispatchBtnAction(post)}
>
<h3>{post}</h3>
</button>
)
)
return (
<div>
<h3> Organisations!!!! </h3>
<h5>{postItems}</h5>
</div>
)
}
}
export default OrgList;
orgDetails.js
import React, { Component } from 'react'
var list =[]
const orgname = org =>
`someURL/${org}`
class OrgDetails extends Component {
state={
devices:[],
}
constructor(props){
super(props);
this.state={
devices: [],
}
this.dispatchBtnAction=this.dispatchBtnAction.bind(this)
}
dispatchBtnAction=(str) => {
list =[]
fetch(orgname(str))
.then(res => res.json())
.then(function (data){
for (let i = 0; i < 3; i++){
//console.log("123")
list.push(data.devices[i].location)
console.log(list)
}
}).then(devices => this.setState({
devices : list,
}));
}
render() {
const devices=this.state.devices.map((dev,i)=>(
<div key={dev}>
<li>{dev}</li>
</div>
))
return (
<div>
<p>{devices}</p>
</div>
)
}
}
export default OrgDetails;
But I am getting this warning...
Warning: Can't call setState on a component that is not yet mounted. This is a no-op, but it might indicate a bug in your application. Instead, assign to this.state directly or define a state = {}; class property with the desired state in the OrgDetails component.
Because of this, the state is not getting changed and the component is not rerendering.
How to eliminate this warning and if any better method is there please do suggest.
As these 2 component are not parent-child components, perhaps you should implement all the logic in the App and than pass state-handlers as props to each component.
Then your components will look something like this:
class App extends Component {
state = { clicks: 0 }
incrementState = () {
const prev = this.state.clicks;
this.setState({ clicks: prev + 1 })
}
render() {
return [
<DisplayComponent counter={this.state.clicks} />,
<ControlComponent onIncrement={this.incrementState} />
];
}
}
Component that displays state
class DisplayComponent extends Component{
render() {
return (<h3>this.props.counter</h3>);
}
}
Component that handles state
class ControlComponent extends Component {
render() {
return (<button onClick={this.props.onIncrement}>click me</button>)
}
}
Well the whole issue is this line var token =new OrgDetails(); This just creates the object. But doesn't mount it in the DOM. It also doesn't reference to the component <OrgDetails/> created in App. So when you try to use token.dispatchBtnAction(post), you are trying to setState on a component that is not mounted in the DOM, hence the error.
This is a really questionable way of making communication in between two components. You are better off using a Parent-Child relationship in between component. Also you can have a look at making Presentational Component and Container components differentiation to make the workflow easy. Have a read at the this link.
Im making my first react ptoject. Im new in JS, HTML, CSS and even web app programing.
What i try to do, is to display some infomration on button click.
I have an API, that looks like this:
endpoint: https://localhost:44344/api/Projects
My Data from it:
[{"id":1,"name":"Mini Jira","description":"Description for first project in list","tasks":null},{"id":2,"name":"Farm","description":"Description for second one","tasks":null}]
And im fine with that, i can get it easily by axios in my react app.
Now i will show you my Project.js Component:
import React, { Component } from "react";
import { ListGroupItem, Button, ButtonToolbar } from "react-bootstrap";
import ProjectDetails from "./ProjectDetails";
class Project extends Component {
render() {
return (
<ButtonToolbar>
<ListGroupItem>{this.props.project.name}</ListGroupItem>
<Button onClick={Here i want to display new component with details }bsStyle="primary">Details</Button>
</ButtonToolbar>
);
}
}
export default Project;
I have all data from api in project type.
My question is, how to display component that i named ProjectDetails.js on button click? I want to show all data stored in project from my api in separate view (new page or somethig like that).
View looks like this:
Thanks for any advices!
EDIT:
based on #Axnyff answer, i edited Project.js. it works ok. But when i want to (for testing) displat project.name, i get error map of undefined. My ProjectDetails.js:
import React, { Component } from "react";
class ProjectDetails extends Component {
state = {};
render() {
return <li>{this.props.project.name}</li>;
}
}
export default ProjectDetails;
EDIT2:
In Project.js in #Axnyff answet i just edited that line:
{this.state.showDetails && (
<ProjectDetails project={this.props.project} />
)}
i passed project by props, now it works like i want too. After click it displays project.name that i clicked on.
You should use state in your React component.
Let's create a field called showDetails in your state.
You can initialize it in your constructor with
constructor(props) {
super(props); // needed in javascript constructors
this.state = {
showDetails: false,
};
}
Then you need to modify the onClick to set that state to true
<Button onClick={() => this.setState({ showDetails : true })} bsStyle="primary">Details</Button>
And then use that state to show or not the ProjectDetails:
{ showDetails && <ProjectDetails /> }
The full component should look like
import React, { Component } from "react";
import { ListGroupItem, Button, ButtonToolbar } from "react-bootstrap";
import ProjectDetails from "./ProjectDetails";
class Project extends Component {
constructor(props) {
super(props); // needed in javascript constructors
this.state = {
showDetails: false,
};
}
render() {
return (
<ButtonToolbar>
<ListGroupItem>{this.props.project.name}</ListGroupItem>
<Button onClick={() => this.setState({ showDetails : true })} bsStyle="primary">Details</Button>
{ this.state.showDetails && <ProjectDetails /> }
</ButtonToolbar>
);
}
}
export default Project;
You can then modify the logic to add a toggling effect etc.
If you haven't done it, you should probably follow the official tutorial
function Bar() {
return <h1>I will be shown on click!</h1>;
}
class Foo extends React.Component {
constructor() {
super();
this.state = { showComponent: false };
}
handleClick = () => {
this.setState({ showComponent: !this.state.showComponent });
};
render() {
return (
<div>
{this.state.showComponent && <Bar />}
<button onClick={this.handleClick}>click</button>
</div>
);
}
}
ReactDOM.render(<Foo />, document.getElementById("root"));
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<div id="root"></div>
I have an App component and a function 'modalToggled' inside its.
I want to pass the function to multiple child components until I get to the last one, the 'interiores' component.
Like this:
<App> -> <Coluna1> -> <MenuPrincipal> -> <Portfolio> -> <PortfolioMenu> -> <interiores>
App Component, the parent of all components:
import React, { Component } from 'react';
import Coluna1 from './Coluna1'
class App extends Component {
constructor(props) {
super(props)
this.state = {
modalOn: false
}
this.modalToggled = this.modalToggled.bind(this)
}
modalToggled = (on) => {
this.setState({modalOn: on});
}
render() {
return (
<div>
<Coluna1 onModalToggle={this.modalToggled}/>
</div>
)
}
}
export default App;
This is the 'Coluna1' the first child component. I did the same thing in the another ones: 'MenuPrincipal', 'Portfolio', 'PortfolioMenu'
class Coluna1 extends Component {
constructor(props){
super(props)
}
render() {
return (
<div>
<Header />
<MenuPrincipal onModalToggle={this.props.modalToggled} />
</div>
)
}
}
export default Coluna1
Therefore here is the last component interiores, when I click on the button there appears an error message:
TypeError: _this.props.onModalToggle is not a function
import React, { Component } from 'react'
import Modal from 'react-responsive-modal';
class Interiores extends Component {
constructor(props) {
super(props)
this.state = {
open: false
}
}
onOpenModal = () => {
this.setState({ open: true });
this.props.onModalToggle(true);
};
onCloseModal = () => {
this.setState({ open: false });
this.props.onModalToggle(false);
};
render() {
const { open } = this.state;
return (
<div>
<button onClick={this.onOpenModal}>Open modal</button>
<Modal open={open} onClose={this.onCloseModal} center></Modal>
</div>
)
}
}
export default Interiores;
Does anybody know how to solve it? Thank you
It happens, because in App class you pass prop with name onModalToggle:
<Coluna1 onModalToggle={this.modalToggled}/>
But in Coluna1 you receive this props with wrong name, modalToggled:
<MenuPrincipal onModalToggle={this.props.modalToggled} />
Just make the names of props equal. In Coluna1 and other intermediate components pass and receive this props as onModalToggle:
<MenuPrincipal onModalToggle={this.props.onModalToggle} />
This is the problem
modalToggled = (on) => {
this.setState({modalOn: on});
}
Since this is a class function it needs to be defined like
modalToggled(on) {
this.setState({modalOn: on});
}
I'm new to React so thank you for your patience in advance. Also using Redux.
I have a list of content pulled from the API, I display the text and a hidden text box and on a state change associated that alternates the visibility of the two. Essentially user can click on the text and edit the text, achieved by inverting the boolean and swapping the display. They can then save it and PUT to server etc.
Since my list length varies, I must initialize a number of state.isVisible[n]. equivalent to the number of content being displayed each time. This number must be counted, after the props come in. I am using Redux so the content is retrieved, stored, then given to props. It's done as the following:
constructor(props){
super(props);
this.state = {
isVisibleObj: {}
}
}
componentWillReceiveProps(){
const { isVisibleObj } = this.state
// set visibility of text box
let obj = {}
Object.keys(this.props.questions).forEach(key => obj[key] = false)
this.setState({isVisibleObj: obj})
}
My initial implementation was that in componentWillReceiveProps I do all the setState() to initialize the isVisible properties to a boolean.
The challenge I am having with this implementation is that, if a user open up multiple items for edit, and if she saves one of them, the PUT request on success would send back the edited content, now updating the store and props. This will trigger componentWillReceiveProps and reset all the visibilities, effectively closing all the other edits that are open.
Any suggestion on how to proceed?
I think you should make two components
List (NamesList.react)
import React, {PropTypes} from 'react';
import NameForm from './NameForm.react';
import Faker from 'Faker'
export default class NamesList extends React.Component {
constructor(){
super();
this.addItem = this.addItem.bind(this);
}
addItem(){
var randomName = Faker.name.findName();
this.props.addName(randomName);
}
render() {
let forms = this.props.names.map((name,i) => {
return <NameForm updateName={this.props.updateName} index={i} key={i} name={name} />
});
return (<div>
<div>{forms}</div>
<button onClick={this.addItem}>Add</button>
</div>);
}
}
NamesList.propTypes = {
names: PropTypes.arrayOf(PropTypes.string).isRequired
};
Form (NameForm.react)
import React, {PropTypes} from 'react';
export default class NameForm extends React.Component {
constructor(props) {
super(props);
this.updateName = this.updateName.bind(this);
this.state = {
showTextBox:false
}
}
updateName(){
this.setState({showTextBox:false});
this.props.updateName(this.props.index,this.refs.name.value);
}
render() {
if(this.state.showTextBox){
return (<div>
<input ref="name" defaultValue={this.props.name} />
<button onClick={this.updateName}>Save</button>
</div>);
}
return (<div onClick={() => {this.setState({showTextBox: !this.state.showTextBox})}}>
{this.props.name}
</div>);
}
}
NameForm.propTypes = {
name:PropTypes.string.isRequired
};
Invoke (App.js)
import React, { Component } from 'react';
import NamesList from './NamesList.react';
class App extends Component {
constructor(){
super();
this.addName = this.addName.bind(this);
this.updateName = this.updateName.bind(this);
this.state = {
names:['Praveen','Vartika']
}
}
addName(name){
let names = this.state.names.concat(name);
this.setState({
names: names
});
}
updateName(index,newName){
let names = this.state.names.map((name,i) => {
if(i==index){
return newName
}
return name;
});
this.setState({names:names});
}
render() {
return (
<NamesList names={this.state.names} updateName={this.updateName} addName={this.addName} />
);
}
}
export default App;
Now if your store changes after user saves something. React wont re-render Child component that didn't change