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onclick props not working with Material UI?

here is my situation on React.js
I have a function on my App.js call selectNumberOfPeople,
then In my child component ( call General) I had a button as:
<button className="selectedNumberOfPeopleButton" onClick={this.selectedNumberOfPeople} value="1">
1
</button>
which was displaying the value in the console on click.
Works perfectly.
I want to use a button from Material UI instead now, so I have replace my button with:
<RaisedButton className="selectedNumberOfPeopleButton"
onClick={this.props.selectedNumberOfPeople}
value="1"
label="1"
labelPosition="before"
primary={true}
/>
But the value doesnt display anymore int he console when using this . . .
though the function being in the parent component I do pass it by:
<General selectNumberOfPeople={this.selectNumberOfPeople} selectedPanel={this.showPanelAndHideOthers} />
and I tried to updated my child component ( General.js) like:
<RaisedButton selectNumberOfPeople={this.props.selectNumberOfPeople}
className="selectedNumberOfPeopleButton"
onClick={this.props.selectedNumberOfPeople}
value="1"
label="1"
labelPosition="before"
primary={true}
/>
but it's still not working....
For your information,
the selectNumberOfPeople is in App.js as
selectNumberOfPeople(value) {
console.log('select number of people');
// update the state and provide a callback handler to be called after the state is updated.
// referencing the state before the call back function
// () => {
// console.log(this.state.numberOfPeople)
// })
// will leave the state with the same value as before the setState function is called.
this.setState(
{
numberOfPeople: value,
},
() => {
console.log(this.state.numberOfPeople);
}
);
}
and in my general.js (child component)
selectedNumberOfPeople(e) {
this.props.selectNumberOfPeople(e.target.value);
const list = document.getElementsByClassName('selectedNumberOfPeopleButton');
for (let i = 0; i < list.length; i++) {
list[i].classList.remove('hover');
}
this.toggleSelectedButtonState(e);
}
Does anyone have any guidance in what I'm doing wrong ?
It will be super !!
Many thanks !

Use this.props.selectNumberOfPeople not selectedNumberOfPeople.
<RaisedButton
className="selectedNumberOfPeopleButton"
onClick={this.props.selectNumberOfPeople}
value="1"
label="1"
labelPosition="before"
primary={true}
/>

you can also try
onClick={()=>this.props.selectedNumberOfPeople}

Multiple state changes in react

Suppose I have a settings screen on my React app, with three settings
enable thingie
use doohickey
activate gizmo
What's the best way to handle all the onchange events from all these controls? Here's what I have at the minute
import React from 'react';
import Modal from 'react-bootstrap-modal';
 
export default class Settings extends React.Component {
constructor (props) {
super(props)
this.state = {
open: false
}
this.handleThingieChange = this.handleThingieChange.bind(this);
this.handleDoohickeyChange = this.handleDoohickeyChange.bind(this);
this.handleGizmoChange = this.handleGizmoChange.bind(this);
}
handleThingieChange(e) {
this.props.onThingieChange(e.target.value)
}
handleDoohickeyChange(e) {
this.props.onDoohickeyChange(e.target.value);
}
handleGizmoChange(e) {
this.props.onGizmoChange(e.target.checked);
}
  render() {
    return (
      <div>
<label>enable thingie</label>
<input type="checkbox" checked={this.props.thingie} onChange={this.handleThingieChange} />
<label>use doohickey</label>
<input type="checkbox" checked={this.props.doohickey} onChange={this.handleDoohickeyChange} />
<label>activate gizmo</label>
<input type="checkbox" checked={this.props.gizmo} onChange={this.handleGizmoChange} />
      </div>
    )
  }
}
And in my <App> component:
thingieChange(thingie){
this.setState({ thingie: thingie })
}
doohickeyChange(doohickey){
this.setState({ doohickey: doohickey })
}
gizmoChange(gizmo){
this.setState({ gizmo: gizmo })
}
// render method is most important
// render method returns JSX template
render() {
return (
<form>
<h2>headerooney</h2>
<Settings
onThingieChange={this.thingieChange.bind(this)}
onDoohickeyChange={this.doohickeyChange.bind(this)}
onGizmoChange={this.gizmoChange.bind(this)} />
</form>
);
}
My app could potentially have 20 or 30 settings, it seems like there must be a better way to do this than by repeating this pattern 20-30 times?
I'm new to react, if I was building this with jquery I'd do something like this:
  <div>
<label>enable thingie</label>
<input type="checkbox" data-property='thingie' />
<label>use doohickey</label>
<input type="checkbox" data-property='doohickey' />
<label>activate gizmo</label>
<input type="checkbox" data-property='gizmo' />
</div>
with a generic click handler like this
$(function(){
$.each(options, function(k, v) {
$("[data-property='" + k + "']")[0].checked = v;
});
$(document).on("click", "input[type='checkbox']", function(){
var propertyName = $(this).data("property");
options[propertyName] = $(this)[0].checked;
console.log(options);
})
});
How do I do something equivalent in react? I don't want to spend two hours writing a handler function for every single setting

If all of your controls are just checkboxes then why not create a single component for a setting and then have a Settings component that lists them all.
You could provide the name of the setting as a property for the component so that it knows what it was updating. You could pass a function from the Settings component to the Setting component that provided the means to update state.
One more complex option for addressing this would be to use Redux but it is probably not necessary for something this straightforward (although it would provide plenty of benefit in terms of simplifying testing, etc).
I would suggest though that as soon as you seen any kind of repeating pattern that you try to abstract it to a reusable component - it will definitely save you time in the long run.

Change a state in react

I'm learning React and as a learning exercise am trying to do a very basic page where there is a form and you put text in an input box, you click submit and the header changes to what you entered. Here is my code so far:
import React, { Component } from 'react';
import './App.css';
class App extends Component {
constructor() {
super();
this.state = {header: 'yeaheheh'}
}
changeHeader(e) {
let newHeader = document.getElementById('input').value();
e.preventDefault();
console.log('submitted');
this.setState(newHeader);
}
render() {
return (
<div>
<h1>{this.state.header}</h1>
<form onSubmit={this.changeHeader.bind(this)} className="change-header-form">
<input id="input" type="text" placeholder="Enter Text Here" />
<input type="submit" value="Submit" />
</form>
</div>
);
}
}
export default App;
At first, when I clicked submit, nothing happened and I got an error in the console that says
Uncaught TypeError: Cannot read property 'setState' of null
I then realized I needed to bind the changeHeader function to this which I changed so before I had:
<form onSubmit={this.changeHeader}...
changed it to
<form onSubmit={this.changeHeader.bind(this)}...
After doing this, the error cleared but my header is still not updating.I read that there has been strong suggestions against changing state via setState is bad practice because calling setState() again could potentially alter the changed state. setState is also an asynchronous operation which would also explain why my header isn't changing.
With all that said, then what would be the best way to handle this? From what I understand, props wouldn't make sense either since those values are stored directly in your component and aren't parameters that can't be dynamically updated. I'm having a hard time understanding the relationship between these different data types and how they are handled in the DOM.

You are setting state incorrectly.
More over to get the data from input fields you can either use controlled input elements(via states) or uncontrolled input elements via "ref" which I have used in below example.
In controlled input element you store the value of input element in state and changes to that value is done by calling onChange method and then setting the state via this.setState({}).
Calling setState causes re-rendering to happen and dom gets the updated data based on new state.
Btw "refs" gets you the direct access to dom elements, in similar way $() was used in jquery and should be avoided if possible because it will lead to very hard to manage and predict dom changes.
Also there are cases where use of "refs" is recommended
There are a few good use cases for refs:
Managing focus, text selection, or media playback.
Triggering imperative animations.
Integrating with third-party DOM libraries.
class App extends React.Component {
constructor() {
super();
this.state = {header: 'yeaheheh'};
}
changeHeader = (e) => {
e.preventDefault();
let newHeader = this.textInput.value;
console.log('submitted');
this.setState({header : newHeader});
}
render() {
return (
<div>
<h1>{this.state.header}</h1>
<form onSubmit={this.changeHeader} className="change-header-form">
<input id="input" ref={(input) => { this.textInput = input; }} type="text" placeholder="Enter Text Here" />
<input type="submit" value="Submit" />
</form>
</div>
);
}
}
ReactDOM.render(<App />, document.getElementById('test'));
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<div id="test">
</div>

Replace this.setState(newHeader); with this.setState({header: newHeader});.

Take a look at this article in the react docs: https://facebook.github.io/react/docs/forms.html#controlled-components.
Basically what you want to do is create another handler for the input. This will be called every time there is a change to the input field and a property in your state will be updated. Then, when you submit the form you can take that new property and "merge" it using setState to become the new header.
JS Bin
class App extends React.Component {
constructor(props) {
super(props);
this.state = {
header: 'yeaheheh',
next: ''
}
this.changeHeader = this.changeHeader.bind(this);
this.updateNext = this.updateNext.bind(this);
}
changeHeader(e) {
e.preventDefault();
this.setState({
header: this.state.next
});
}
updateNext(e) {
this.setState({
next: e.target.value
});
}
render() {
return (
<div>
<h1>{this.state.header}</h1>
<form onSubmit={this.changeHeader} className="change-header-form">
<input id="input" type="text" placeholder="Enter Text Here" onChange={this.updateNext} />
<input type="submit" value="Submit" />
</form>
</div>
);
}
}
ReactDOM.render(<App />, document.getElementById('app'));
Maybe this bin will provide a little better context at what I'm trying to describe.

There's the small bug in your code preventing it from working (this.setState(newHeader) -> this.setState({header: newHeader});), but the thing is that your code is not idiomatic for React.
You are supposed to use controlled components instead of grabbing the values from the form's inputs on submit, as you would do with jQuery.
"Controlled component" is a silly name for the pattern where an input's state is mapped to the application state, so an input itself behaves as if it would be kinda "stateless". In your case, you need to have separate component state member for every text input you've got. Input control should look like this:
<input value={ this.state.inputValue }
onChange={ e => this.setState({ inputValue : e.target.value }) }
/>
Now it's bound to your inputValue state member, so you can just take it from the state at any moment you need. On form's submit handler, in your case.
That's it. Your code must be fixed accordingly. Refer to the "controlled components" manual for further details, it's the really important React concept.

You should modified your function like this..
constructor(props) {
super(props);
_that = this;
}
changeHeader = (e) => {
e.preventDefault();
let newHeader = this.textInput.value;
console.log('submitted');
_that.setState({header : newHeader});
}

How to get Material-UI's <TextField/> to return correctly with ref='' like <input/> in ReactJS?

With the following method:
handleClick(event) {
const inputText = this.refs.inputText
console.log(inputText.value.trim())
}
I am trying to get Material-UI's <TextField/> to return the input text correctly with ref like the <input/> can with <button/> triggering it:
<input
className='form-control'
placeholder='Input Text'
ref='inputText'
type='text'
/>
<button
onClick={(event) => this.handleClick(event)}
>
And I attempted the following with <TextField/>, but it returns as undefined. How can I get it to return inputted text correctly like the <input/> above?
<TextField
hint='Enter text'
className='form-control'
ref='inputText'
type='text'
/>

I would suggest this approach:
Set up your textfield with a value and onChange function that are hooked into redux itself, where the onChange function just updates the value.
So you'd have something like this :
<TextField
value={this.props.textFieldValue}
onChange={this.props.textFieldChange}
Where the textFieldChange is an action that simply updates the textFieldValue. Most forms in redux will work something like this. Keep in mind the names i made up for those props and action are just for example. If you have a big form you might want to consider have part of the state tree dedicated to the form itself where you have :
state: {
form: {
textField: ...your textfield value here,
name: ...,
whateverElse: ...
}
};
I like doing this with redux because I can make that architect form part of the state to look like the json payload of wherever I'm sending it to, so there I can just send the form went I want to send it.
Anyways, back to this example. When you click your handleClick now. All you need to do is this to get the value:
handleClick(event) {
console.log(this.props.textFieldValue.trim());
}
Because the textfield is updated with every change, you always have access to it in your state. This also gives you flexibility over the refs approach, because if you use refs you will have a lot harder of a time getting access to that form in other components. With this approach, all the information is on your state so you can access it anytime, as long as you manage your props.

You should use the onChange={} to get the value:
_onChange = (e) => {
console.log(e.target.value);
}
<TextField
onChange={this._onChange}
/>

Here's a better solution than using onchange event, we get directly the value of the input created by material-ui textField :
create(e) {
e.preventDefault();
let name = this.refs.inputText.input.value;
alert(name);
}
constructor(){
super();
this.create = this.create.bind(this);
}
render() {
return (
<form>
<TextField ref="inputText" hintText="" floatingLabelText="Your name" /><br/>
<RaisedButton label="Create" onClick={this.create} primary={true} />
</form>
)}
hope this helps.

React input defaultValue doesn't update with state

I'm trying to create a simple form with react, but facing difficulty having the data properly bind to the defaultValue of the form.
The behavior I'm looking for is this:
When I open my page, the Text input field should be filled in with the text of my AwayMessage in my database. That is "Sample Text"
Ideally I want to have a placeholder in the Text input field if the AwayMessage in my database has no text.
However, right now, I'm finding that the Text input field is blank every time I refresh the page. (Though what I type into the input does save properly and persist.) I think this is because the input text field's html loads when the AwayMessage is an empty object, but doesn't refresh when the awayMessage loads. Also, I'm unable to specify a default value for the field.
I removed some of the code for clarity (i.e. onToggleChange)
window.Pages ||= {}
Pages.AwayMessages = React.createClass
getInitialState: ->
App.API.fetchAwayMessage (data) =>
#setState awayMessage:data.away_message
{awayMessage: {}}
onTextChange: (event) ->
console.log "VALUE", event.target.value
onSubmit: (e) ->
window.a = #
e.preventDefault()
awayMessage = {}
awayMessage["master_toggle"]=#refs["master_toggle"].getDOMNode().checked
console.log "value of text", #refs["text"].getDOMNode().value
awayMessage["text"]=#refs["text"].getDOMNode().value
#awayMessage(awayMessage)
awayMessage: (awayMessage)->
console.log "I'm saving", awayMessage
App.API.saveAwayMessage awayMessage, (data) =>
if data.status == 'ok'
App.modal.closeModal()
notificationActions.notify("Away Message saved.")
#setState awayMessage:awayMessage
render: ->
console.log "AWAY_MESSAGE", this.state.awayMessage
awayMessageText = if this.state.awayMessage then this.state.awayMessage.text else "Placeholder Text"
`<div className="away-messages">
<div className="header">
<h4>Away Messages</h4>
</div>
<div className="content">
<div className="input-group">
<label for="master_toggle">On?</label>
<input ref="master_toggle" type="checkbox" onChange={this.onToggleChange} defaultChecked={this.state.awayMessage.master_toggle} />
</div>
<div className="input-group">
<label for="text">Text</label>
<input ref="text" onChange={this.onTextChange} defaultValue={awayMessageText} />
</div>
</div>
<div className="footer">
<button className="button2" onClick={this.close}>Close</button>
<button className="button1" onClick={this.onSubmit}>Save</button>
</div>
</div>
my console.log for AwayMessage shows the following:
AWAY_MESSAGE Object {}
AWAY_MESSAGE Object {id: 1, company_id: 1, text: "Sample Text", master_toggle: false}

Another way of fixing this is by changing the key of the input.
<input ref="text" key={this.state.awayMessage ? 'notLoadedYet' : 'loaded'} onChange={this.onTextChange} defaultValue={awayMessageText} />
Update:
Since this get upvotes, I will have to say that you should properly have a disabled or readonly prop while the content is loading, so you don't decrease the ux experience.
And yea, it is most likely a hack, but it gets the job done.. ;-)

defaultValue is only for the initial load
If you want to initialize the input then you should use defaultValue, but if you want to use state to change the value then you need to use value. Personally I like to just use defaultValue if I'm just initializing it and then just use refs to get the value when I submit. There's more info on refs and inputs on the react docs, https://facebook.github.io/react/docs/forms.html and https://facebook.github.io/react/docs/working-with-the-browser.html.
Here's how I would rewrite your input:
awayMessageText = if this.state.awayMessage then this.state.awayMessage.text else ''
<input ref="text" onChange={this.onTextChange} placeholder="Placeholder Text" value={#state.awayMessageText} />
Also you don't want to pass placeholder text like you did because that will actually set the value to 'placeholder text'. You do still need to pass a blank value into the input because undefined and nil turns value into defaultValue essentially. https://facebook.github.io/react/tips/controlled-input-null-value.html.
getInitialState can't make api calls
You need to make api calls after getInitialState is run. For your case I would do it in componentDidMount. Follow this example, https://facebook.github.io/react/tips/initial-ajax.html.
I'd also recommend reading up on the component lifecycle with react. https://facebook.github.io/react/docs/component-specs.html.
Rewrite with modifications and loading state
Personally I don't like to do the whole if else then logic in the render and prefer to use 'loading' in my state and render a font awesome spinner before the form loads, http://fortawesome.github.io/Font-Awesome/examples/. Here's a rewrite to show you what I mean. If I messed up the ticks for cjsx, it's because I normally just use coffeescript like this, .
window.Pages ||= {}
Pages.AwayMessages = React.createClass
getInitialState: ->
{ loading: true, awayMessage: {} }
componentDidMount: ->
App.API.fetchAwayMessage (data) =>
#setState awayMessage:data.away_message, loading: false
onToggleCheckbox: (event)->
#state.awayMessage.master_toggle = event.target.checked
#setState(awayMessage: #state.awayMessage)
onTextChange: (event) ->
#state.awayMessage.text = event.target.value
#setState(awayMessage: #state.awayMessage)
onSubmit: (e) ->
# Not sure what this is for. I'd be careful using globals like this
window.a = #
#submitAwayMessage(#state.awayMessage)
submitAwayMessage: (awayMessage)->
console.log "I'm saving", awayMessage
App.API.saveAwayMessage awayMessage, (data) =>
if data.status == 'ok'
App.modal.closeModal()
notificationActions.notify("Away Message saved.")
#setState awayMessage:awayMessage
render: ->
if this.state.loading
`<i className="fa fa-spinner fa-spin"></i>`
else
`<div className="away-messages">
<div className="header">
<h4>Away Messages</h4>
</div>
<div className="content">
<div className="input-group">
<label for="master_toggle">On?</label>
<input type="checkbox" onChange={this.onToggleCheckbox} checked={this.state.awayMessage.master_toggle} />
</div>
<div className="input-group">
<label for="text">Text</label>
<input ref="text" onChange={this.onTextChange} value={this.state.awayMessage.text} />
</div>
</div>
<div className="footer">
<button className="button2" onClick={this.close}>Close</button>
<button className="button1" onClick={this.onSubmit}>Save</button>
</div>
</div>
That should about cover it. Now that is one way to go about forms which uses state and value. You can also just use defaultValue instead of value and then use refs to get the values when you submit. If you go that route I would recommend you have an outer shell component (usually referred to as high order components) to fetch the data and then pass it to the form as props.
Overall I'd recommend reading the react docs all the way through and do some tutorials. There's lots of blogs out there and http://www.egghead.io had some good tutorials. I have some stuff on my site as well, http://www.openmindedinnovations.com.

it's extremely simple, make defaultValue and key the same:
<input defaultValue={myVal} key={myVal}/>
This is one of the recommended approaches at https://reactjs.org/blog/2018/06/07/you-probably-dont-need-derived-state.html#recommendation-fully-uncontrolled-component-with-a-key

To force the defaultValue to re-render all you need to do is change the key value of the input itself. here is how you do it.
<input
type="text"
key={myDynamicKey}
defaultValue={myDynamicDefaultValue}
placeholder="It works"/>

Maybe not the best solution, but I'd make a component like below so I can reuse it everywhere in my code. I wish it was already in react by default.
<MagicInput type="text" binding={[this, 'awayMessage.text']} />
The component may look like:
window.MagicInput = React.createClass
onChange: (e) ->
state = #props.binding[0].state
changeByArray state, #path(), e.target.value
#props.binding[0].setState state
path: ->
#props.binding[1].split('.')
getValue: ->
value = #props.binding[0].state
path = #path()
i = 0
while i < path.length
value = value[path[i]]
i++
value
render: ->
type = if #props.type then #props.type else 'input'
parent_state = #props.binding[0]
`<input
type={type}
onChange={this.onChange}
value={this.getValue()}
/>`
Where change by array is a function accessing hash by a path expressed by an array
changeByArray = (hash, array, newValue, idx) ->
idx = if _.isUndefined(idx) then 0 else idx
if idx == array.length - 1
hash[array[idx]] = newValue
else
changeByArray hash[array[idx]], array, newValue, ++idx

Related issue
Setting defaulValue on control din't not update the state.
Doing reverse works perfectly:
Set state to default value, and the control UI gets updated correctly as if defaulValue was given.
Code:
let defaultRole = "Owner";
const [role, setRole] = useState(defaultRole);
useEffect(() => {
setMsg(role);
});
const handleChange = (event) => {
setRole(event.target.value );
};
// ----
<TextField
label="Enter Role"
onChange={handleChange}
autoFocus
value={role}
/>

Define a state for your default value
Surround your input with a div and a key prop
Set the key value to the same value as the defaultValue of the input.
Call your setDefaultValue defined at the step 1 somewhere to re-render your component
Example:
const [defaultValue, setDefaultValue] = useState(initialValue);
useEffect(() => {
setDefaultValue(initialValue);
}, false)
return (
<div key={defaultValue}>
<input defaultValue={defaultValue} />
</div>
)

Give value to parameter "placeHolder".
For example :-
<input
type="text"
placeHolder="Search product name."
style={{border:'1px solid #c5c5c5', padding:font*0.005,cursor:'text'}}
value={this.state.productSearchText}
onChange={this.handleChangeProductSearchText}
/>

Use value instead of defaultValue and change the value of the input with the onChange method.