I have a simple React form in javascript that I can't seem to get to work. Its extremely simple, but nothing will load to the browser.
import React from 'react';
import { render } from 'react-dom';
function signUp() {
function handle () {console.log(document.getElementById('year').value);
}
return (
<>
<select id="year">
<option>Freshamn</option>
<option>Freshamn</option>
</select>
<div>Name</div>
<input type="text"/>
<div>Email</div>
<input type="text"/>
<div>Password</div>
<input type="text"/>
<div><input type="checkbox"/> Remember me</div>
<button onClick={handle}>Submit</button>
</>
)
};
ReactDOM.render(<signUp/>, document.getElementById("root"));
What am I doing wrong here?
There could be many problems. I would try changing signUp to SignUp (change the capitalization). Also, you shouldn't use document.getElementById. You should give the input a value of a state and use that state value instead.
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I want to get value filled inside input bar to show inside input bar, I know its sounds illogical but I am new to react and I am following a course
code is below
import React from 'react';
class Searchbar extends React.Component{
state={term :'a'}
// e means event
onChangeHandler=(e)=>{
console.log(e.target.value);
this.setState=({term:e.target.value});
}
render(){
return(
<div className="ui segment">
<form className="ui form">
<div className="field">
<label>Image Search</label>
{/* <input type="text" value={this.state.term} onChange={this.onChangeHandler}/> */}
<input type="text" value={this.state.term} onChange={ e=>(this.setState=({term:e.target.value}),console.log(e.target.value))}/>{/* alternate syntax for event handler */}
</div>
</form>
</div>
)
}
}
export default Searchbar;
You're almost there actually!
A small tweak to your code does the job:
import React from "react";
class Searchbar extends React.Component {
state = { term: "a" };
onChangeHandler = (e) => {
this.setState((state) => {
return { term: e.target.value };
});
};
render() {
return (
<div className="ui segment">
<form className="ui form">
<div className="field">
<label>Image Search</label>
<input
type="text"
value={this.state.term}
onChange={(e) => this.onChangeHandler(e)}
/>
</div>
</form>
</div>
);
}
}
export default Searchbar;
As outlined here, you shouldn't set the state directly.
My recommendation
Personally, I would make a few changes and I'll explain why.
Class vs Functional
My preference goes out to functional components nowadays. With hooks you'll have all the functionality that classes provide, but with less verbose code. (in my experience).
Also, if you're using a very small and limited component like this, setting an object as your state isn't always needed. A simple string would suffice in this use case.
My change
This is what I would personally write if I had to make a simple input component with state.
import { useState } from "react";
const Searchbar = () => {
const [input, setInput] = useState("");
return (
<div className="ui segment">
<form className="ui form">
<div className="field">
<label>Image Search</label>
<input
type="text"
value={input}
onChange={(e) => setInput(e.target.value)}
/>
</div>
</form>
</div>
);
};
export default Searchbar;
I highly recommend you start looking into functional components, if my experience in the field has taught me anything
<input
type="text"
value={this.state.term}
onChange={(e) => (
(this.setState({ term: e.target.value })),
console.log(e.target.value)
)}
/>
I am currently creating a form that has an unknown number of sensor fields within it. I've gotten the front end working beautifully. However, now I want to grab the user info out of those dynamically generated component fields and I can't figure out how. Here is where I'm generating the components:
{this.state.sensors.map((item, i) => (
<UpdateSensorInfo
key={i}
sensorName={item.sensorName}
sensorLowerLimit={item.sensorLowerLimit}
sensorUpperLimit={item.sensorUpperLimit}
/>
))}
And here is the actual component itself:
import React, { Component } from "react";
import "./updateSensorInfo.css";
class UpdateSensorInfo extends Component {
render() {
return (
<div>
<div className="sensorInfoFrame">
<div className="sensorFieldBody">
<label className="sensorTextFieldLabel">Sensor Name:</label>
<input
type="text"
name="text"
placeholder=""
className="sensorTextField"
defaultValue={this.props.sensorName}
required
/>
</div>
<div className="sensorFieldBody">
<label className="sensorTextFieldLabel">Sensor Upper Limit:</label>
<input
type="number"
name="text"
placeholder=""
className="sensorTextField"
defaultValue={this.props.sensorUpperLimit}
required
/>
</div>
<div className="sensorFieldBody">
<label className="sensorTextFieldLabel">Sensor Lower Limit:</label>
<input
type="number"
name="text"
placeholder=""
className="sensorTextField"
defaultValue={this.props.sensorLowerLimit}
required
/>
</div>
</div>
</div>
);
}
}
export default UpdateSensorInfo;
I would like to uniquely identify each text field within each generated component. How can I do this?
For anyone who has a similar situation, I have found a solution that works. There is a way to use the key that is created for each of the components within each component. use the following as an id or name for the input element:
id={`${this._reactInternalFiber.key}-additionalNameHere`}
This uses the key and will allow you to loop over the inputs within the components.
I'm creating a simple CRUD app using React for my front-end, and I'm having trouble with this error:
app.js:21988 Warning: Invalid DOM property `for`. Did you mean `htmlFor`?
Here's my code:
import React, { Component } from 'react';
import axios from 'axios';
export default class Add extends Component {
constructor()
{
super();
this.state={
blogs_name:''
}
}
render() {
return (
<div>
<form>
<div className="form-group">
<label for="blogs_name">Title</label>
<input
type="text"
className="form-control"
id="blogs_name"
value={this.state.blogs_name}
/>
</div>
<button type="submit">Submit</button>
</form>
</div>
);
}
}
I assume that it has to do something with the for property in my label.
Any help is appreciated.
When using React, you can't use the for keyword in JSX, since that's a javascript keyword (remember, JSX is javascript so words like for and class can't be used because they have some other special meaning!)
To circumvent this, React elements use htmlFor instead (see React docs for more information).
So, your render function should be (I only replaced for with htmlFor):
render() {
return (
<div>
<form onSubmit={this.onSubmit} >
<div className="form-group">
<label htmlFor="blogs_name">Title</label>
<input type="text" className="form-control" id="blogs_name"
value={this.state.blogs_name}
onChange={this.onChangeBlogsName} />
</div>
<button type="submit" className="btn btn-primary">Submit</button>
</form>
</div>
);
}
Replace for="" with htmlFor=""
In your case change this
<label for="blogs_name">Title</label>
To this
<label htmlFor="blogs_name">Title</label>
for is a reserved word in JavaScript this is why when it comes to HTML attributes in JSX you need to use something else, React team decided to use htmlFor respectively. You can check the list of attributes from here
Short answer, Remove
for="blogs_name"
In your case.
I have a stateless react component that is a little pop up. It takes some data from the user, and passes that back to its parent, where it executes the work.
What is the best way for this component to have a handleSubmit() function, that takes the user input, and sends it back to the parent?
import React, { Component } from "react";
import "../../../node_modules/bulma/css/bulma.css";
const Transfer = (props, token, web3) => {
return (
<div className="modal is-active">
<div className="modal-background" onClick={props.onClick} />
<div className="modal-card">
<section className="modal-card-body">
<div className="content">
<h1 className="title"> Transfer Tokens </h1>
<p className="has-text-danger">
Requires that you are the owner of the token you are transferring
</p>
<p className="subtitle">How it works</p>
<p className="">
Enter the ID of the token you want to transfer, the address to
whom its going to, and thats it!
</p>
//problem area
<form onSubmit={props.onClickSubmit}>
<label htmlFor="text">Address to recieve token</label>
<input
name="Address"
className="input is-info "
required="true"
/>
<label htmlFor="number">Token ID</label>
<input
className="input is-info"
name="Token ID"
type="number"
required="true"
/>
<a className="button is-pulled-right">Submit</a>
</form>
</div>
</section>
<footer className="modal-card-foot is-clearfix">
<a className="button" onClick={props.onClick}>
Cancel
</a>
</footer>
</div>
</div>
);
};
export default Transfer;
I pass in as a prop, onClickSubmit, in my parent component, and that contains the logic for what I'm trying to do.
Very new to stateless react components
It will be difficult to accomplish what you want with a stateless component since you cannot use either refs or state in a stateless component. You can think of a stateless component as a pure function that returns a piece of UI depending on the props you give it.
You could instead use a stateful component and e.g. store the input values in state and call the onClickSubmit prop function with this state when the user submits the form.
If you want to build stateless forms component, I send you a lib that I'm working on:
react-distributed-forms
This allow you to build your Transfer Component this way, (pay attention to use Input instead of input and Button instead of button):
import React, { Component } from "react";
import "../../../node_modules/bulma/css/bulma.css";
import { Input, Button } from "react-distributed-forms";
const Transfer = (props, token, web3) => {
return (
<div className="modal is-active">
<div className="myForm">
<label htmlFor="text">Address to receive token</label>
<Input name="Address" className="input is-info " required="true" />
<label htmlFor="number">Token ID</label>
<Input
className="input is-info"
name="Token ID"
type="number"
required="true"
/>
<Button name="submit" className="button is-pulled-right">
Cancel
</Button>
</div>
</div>
);
};
export default Transfer;
And then in your parent Component, wherever it is in the hierarchy, you simply do:
<Form onSubmit={({ name }) => { console.log(name); }} onFieldChange={({ name, value} ) => { console.log(name, value); }}>
...whatever
<Transfer />
...whatever
</Form>
onFieldChange will receive every input change.
onSubmit will receive the attribute "name" on the Button when you click it.
react-distributed-forms use React context API, so you don't have to pass directly props, it just works. Is built for really dynamic forms...
I have been playing around with fields in React, but am running into the issue where a text input is not updating (whilst the properties are). I have tried to do it through a class/state component, but to no avail. I was kind-of hoping to be able to make specific form-only components that are completely cut-off from stores. Can anyone point me in the right direction?
import React from 'react';
export default (props) => {
function editProjectNameChanged(event, syntheticEvent) {
debugger;
props.editProject.name = syntheticEvent.target.value;
}
return (
<div className="col-xs-5 col-md-5">
<form>
<div className="form-group">
<label htmlFor="management-projects-name">Project name</label>
<input type="text" className="form-control" id="management-projects-name"
value={props.editProject.name}
onUserInput={editProjectNameChanged.bind(null, event)}
placeholder="Project name" />
</div>
</form>
</div>
);
}
Thanks in advance.. This whole form thing is more difficult than I thought it would!
You shouldn't change the props in the child. That is a good job for the state. It's not a good idea to update props because parent component is not notified of the change and the state is more useful because when you call setState() the component is redraw. Something like that (I haven't tested it)
import React from 'react';
export class YourComponent extends React.Component{
constructor(){
this.state = {
name: this.props.editProject.name
};
}
editProjectNameChanged(event, syntheticEvent) {
this.setState({
name: syntheticEvent.target.value
});
}
render(){
return <div className="col-xs-5 col-md-5">
<form>
<div className="form-group">
<label htmlFor="management-projects-name">Project name</label>
<input type="text" className="form-control" id="management-projects-name"
value={props.editProject.name}
onUserInput={editProjectNameChanged.bind(this, event)}
placeholder="Project name" />
</div>
</form>
</div>;
}
}
You shouldn't mutate props the way you do it from within a component. If you do not want your component do manage the state, it should instead accept a callback as a prop, that it would call on user input.
The parent component would then decide whether or not, and how, to update the value, and pass it back to your component as a prop.
<input value={ props.value } onChange={ e => props.onChange(e.target.value) } />
Mutating directly the props object has no effect since version 0.13. You can find here the blog post explaining why this behaviour was introduced