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onChange event fires on wrong mapped file input element

I am stuck on this issue with onChange handler being fired on a wrong element after .map function. I have a component, which I use to display mapped values, which looks like this:
const Step: React.FC<StepProps> = ({ status, title, text, onClick, onChange }) => {
return (
<button disabled={status === CompletionStatus.Completed} className={Styles.item} onClick={onClick}>
<mui.IconButton css={css.completionIcon} disabled={status === CompletionStatus.Completed}>
{status === CompletionStatus.Completed ? <muiIcons.Check /> : <Plus />}
</mui.IconButton>
<div className={Styles.content}>
<span className={status === CompletionStatus.Completed ? Styles.titleCompleted : Styles.title}>{title}</span>
<span className={status === CompletionStatus.Completed ? Styles.textCompleted : Styles.text}>{text}</span>
</div>
{onChange && (
<>
<label htmlFor="file-button" className={Styles.inputLabel} />
<input id="file-button" className={Styles.input} type={'file'} onChange={onChange} />
</>
)}
</button>
);
};
So, some of the mapped elements are being used with onClick, and two use onChange to gain photos from the user.
The issue is, that every time I trigger the onChange event on any of those inputs, only the first ones fires, e.g (I added this onChange function to test the name of the element that is being fired, and every time only the first one in the list is being console.logged)
onChange={(event: any)=> {
console.log(event, step);
event.target.value = null;
}}

So, I have figured out the issue here, maybe someone finds this helpful.
Having input with type file only having one id (file-button) was causing only the first such input to work
<label htmlFor="file-button" className={Styles.inputLabel} />
<input id="file-button" className={Styles.input} type={'file'} onChange={onChange} />
The way I fixed this, was basically having that id property unique, so I passed an index to the component and changed the id to
id={`file-button-${index}`}

Sounds like you may not have set a key for each item in your mapping function.
{yourData.map((item, index) => <Component key={`item-${index}`} item={item} />)}

Can value of input box be set to to empty string on clicking submit button when the input is in a stateless functional component?

How to clear the value inside the input in function Admin after I click the "Add" button? Should i use another class based component instead of a functional component?
I have set the value of one of the input box as : value={props.item} and in the this.setState I update the value of item as item:"".
AddInfo(info){
let s = this.state.products;
let obj ={name:""};
obj.name=info.productName;
s.push(obj);
this.setState({
products:s,
item:"" //Here i set the value of item equal to an empty string.
})
console.log(this.state.products);
}
function Admin(props){
let productName="";
return (
<div>
<input type="text" required placeholder="Product Name" onChange={(e)=>{productName=e.target.value}} value={props.item}></input><br/>
<button type="Submit" onClick{(e)=>props.AddInfo({productName})}>Add</button>
</div>
)
}

You have to save your input within a local state of the input function:
AddInfo(info){
let s = this.state.products;
let obj ={name:""};
obj.name=info.productName;
s.push(obj);
this.setState({
products:s,
})
console.log(this.state.products);
}
function Admin(props){
const [productName, setProductName] = useState('');
return (
<div>
<input type="text" required placeholder="Product Name" onChange={(e)=> setProductName(e.target.value) value={productName}></input><br/>
<button type="Submit" onClick{(e)=> {props.AddInfo({productName}); setProductName('')}}>Add</button>
</div>
)
}
This will work for you, since you are not mutating the productName variable anymore but now you are saving it in a local state of that input function.
Hope this helps!

Admin is like a form, and the main decision you have to make is rather you want it to be controlled (info is stored in stated, and state is reflected in the ui), or uncontrolled (info is taken from the dom once 'Add' is clicked.
Since you want to empty the input once 'Add' is clicked it makes sense to make this component controlled.
The next decision is rather you want it to be a functional component, or a class component. In nowadays it doesn't really matter (functional components can now use state with the state hook).
To store state in you functional component use React's useState hook.
function Admin({addInfo}){
const [productName, setProductName] = useState(")
return (
<div>
<input
type="text"
placeholder="Product Name"
onChange={(e)=>{
setProductName(e.target.value)
}
value={prodcutName}>
</input>
<button
onClick{(e)=>{
props.addInfo({productName})
setProductName("") // Will set the input to an empty string
}
>
Add
</button>
</div>
)
}

React - changing input value from a state

Alrighty, so I'm using some color picker that changes my this.state.colorPicked and that works fine, now I have an input field I'd like to write a function that I can call that would concat the value of my state colorPicked if it was empty, or concat comma and that value if it was not, how can I access this input field?
I'm using react-bootstrap
<InputGroup className="mb-3">
<FormControl
name="color"
onChange={this.change}
placeholder="Available Colors"
aria-label="Available Colors"
/>
</InputGroup>
<div style={{ display: "flex", "flex-direction": "row" }}>
<TwitterPicker
className="mb-3"
onChange={this.handleColorChange}
/>
<Button
style={{
background: this.state.colorPicked
}}
onClick={() => this.addColor(this.state.colorPicked)}
>
Add Color!
</Button>
</div>
TIA
Clarification: I want to pick the color, the onchange detector sets it to the state and hence the button's background, now on button click I want to add it's hex (the state) to the text field as text input, if input is not empty I would precede that with a comma.

With react forms we use 2 way binding from state, onChange and value attributes.
First add the value attribute and set it to state property for ex inputField.
<FormControl
name="color"
onChange={this.change}
placeholder="Available Colors"
aria-label="Available Colors"
value=={this.state.inputField}
/>
Now you can write a logic inside your change function.. something like
change = (e)=>{
this.setState({inputField:e.target.value}
// then copy array from state
let arrFromState = [...this.state.colorPicked]
let updatedArray = [...arrFromState, this.state.inputField]
// or use concat, push etc
this.setState({colorPicked:updatedArray})
}
I didn't understood the exact thing you wanted to do.
But thats the basic approach while working with react forms. Two way binding

To access input value you can use onChange method on your input, pass it an event and access it through event.target.value. It should look similar to this:
<input onChange={(event) => logInputValue(event)}
const logInputValue = ({ event: { target: { value } = {} } }) => { console.log(value) }

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.