Purpose:
After the keyboard pops up, a shortcut input box with the specified text appears above it. After clicking, the corresponding text such as"https://" or "www." will be appended to the dialog box.
Problem:
I can't get the value in the input dialog in real time and modify it by functions other than keyboard input.
effort made：
The dialog I'm using is referenced from react-native-dialogs。I can't find a way to pass state into the input area of this dialog.
Also didn't find a way to get the value of the live input.
I thought if there are other dialog components that support getting the value of the modified input, but I didn't find one.
Notice that the Dialog.Input of react-native-dialog is just a TextInput. Thus, we can achieve this as usual using the onChangeText callback and the value prop of TextInput.
Here is a minimal example.
const [visible, setVisible] = useState(false);
const [value, setValue] = useState("");
return (
<View style={styles.container}>
<Button title="Show dialog" onPress={() => setVisible(true)} />
<Dialog.Container visible={visible}>
<Dialog.Title>Please enter the url you want to bookmark</Dialog.Title>
<Dialog.Description>
Message - optional
</Dialog.Description>
<Dialog.Input onChangeText={setValue} value={value} />
<Dialog.Button label="Ok" onPress={() => setVisible(false)} />
<Dialog.Button label="Set Text via function" onPress={() => setValue("Hello World")} />
</Dialog.Container>
</View>
);
The state value will be updated while you are typing. You have access to it while the dialog is open. You can set the value manually by using the setValue function of the value state as usual. This can be done while the dialog is open.
Here is a little snack for showcasing.
<Dialog.Container visible={this.state.dialogSendEmailVisible}>
<Dialog.Title>Password Recovery</Dialog.Title>
<Dialog.Input label="Email"></Dialog.Input>
<Dialog.Button label="OK" onPress={this.handleSendEmail} />
</Dialog.Container>
I have this simple dialog, this is being used for password recovery purposes. I am not a FE developer, and I am not finding how can I pass the value typed on Email field to handleSendEmail function. Github and npm pages do not have any example.
Github page: https://github.com/mmazzarolo/react-native-dialog
PS: This can be a very react native basic feature, but I am not findindg a way...
Assuming that the Dialog Inputs/Button extend React Native's own - then you can call:
onSubmitEditing and onChangeText
From the docs:
onSubmitEditing
Callback that is called when the text input's submit button is
pressed. Invalid if multiline={true} is specified.
TYPE REQUIRED
function No
And
onChangeText
Callback that is called when the text input's text changes. Changed
text is passed as an argument to the callback handler.
TYPE REQUIRED
function No
It means something like below:
<Dialog.Input label="Email"
onChangeText={email => this.setState({email})}
value={this.state.email}
onSubmitEditing={
(event) => this.doSomethingWithSubmit(event)
}
>
</Dialog.Input>
UPDATE
So I have tested this, and it works as below - side note - I'm using Typescript so just remove the types ( : string) etc:
In Render
return (
<View>
<View>
<Button onPress={this.showDialog}>
<Text>Show Dialog</Text>
</Button>
<Dialog.Container visible={true}>
<Dialog.Title>Password Recovery</Dialog.Title>
<Dialog.Input label="Email" onChangeText={(email : string) => this.handleEmail(email)}
></Dialog.Input>
<Dialog.Button label="OK" onPress={this.handleSendEmail} />
</Dialog.Container>
</View>
</View>
)
handleEmail:
private handleEmail = (email : string) => {
console.log("email");
console.log(email);
}
Result:
Further
As a side note of this project, I noticed when I used Live reload - that the Dialog was never re-rendered rather, rendered on top of the old Dialog. I would take this into consideration. Perhaps it was my environment, but everything else worked fine.
I have the following issue with a TextInput
User types: Hello
Input field shows Hello
I clear the text input without losing focus
Input field shows ""
User types: A
Input field shows HelloA
If the user removes the focus from the TextInput and focuses back on it before typing again, the behavior goes as expected and the new text contains only the input from after the clearing
How can I properly clear the TextInput without the need to go off focus?
Here is the minimum code required to trigger the issue:
export default class MyInput extends Component {
clearInput() {
this.textInput.clear();
}
render() {
return (
<View>
<Button title="clear" onPress={this.clearInput.bind(this)} />
<TextInput
ref={component => (this.textInput = component)}
/>
</View>
);
}
}
I'm not sure when to use onChange vs onChangeText in a TextInput component. I know onChangeText accepts the changed text as an arg in the callback, but is that why you would use onChangeText, since you can then update state within the callback?
UPDATE 26.08.2019
Since the initial version of the answer, TextInput's API has changed, and answer below is no longer valid. I haven't worked with react-native for more than 2 years now, so I can't really tell which version had these changes.
Regarding the answer, onChangeText is still a simple prop, that gives whatever is the value of the input field on every change.
onChange on the other hand, passes an event with { nativeEvent: { eventCount, target, text} } (as mentioned in the comment to this answer). Now, I cannot tell with confidence, why do you need eventCount and target. I can only state, that eventCount is increased every time you interact with TextInput component (character added, removed, all deleted, value pasted) and target is a unique integer for that TextInput field. And text is the same value as in onChangeText
So basically, I would suggest to use onChangeText, as a more straight forward prop.
If you want to accomplish functionality like in the old answer(below), you can create custom component, that wraps TextInput and receives custom properties and passes them to the onChange prop later. Example below:
const MyTextInput = ({ value, name, type, onChange }) => {
return (
<TextInput
value={value}
onChangeText={text => onChange({ name, type, text })}
/>
);
};
And then use it whenever you need to use TextInput
handleChange(event) {
const {name, type, text} = event;
let processedData = text;
if(type==='text') {
processedData = value.toUpperCase();
} else if (type==='number') {
processedData = value * 2;
}
this.setState({[name]: processedData})
}
<MyTextInput name="username" type="text" value={this.state.username} onChange={this.handleChange}}>
<MyTextInput name="password" type="number" value={this.state.password} onChange={this.handleChange}}>
OLD ANSWER
onChangeText is basically a simplified version of onChange, so you can easily use it, without the hassle of going through event.target.value to get changed value.
So, when should you use onChange and when onChangeText?
If you have simple form with few textinputs, or simple logic, you can go straight away and use onChangeText
<TextInput value={this.state.name} onChangeText={(text) => this.setState({name: text})}>
If you have more complicated forms and/or you have more logic in handling data (like handling text differently from number) when user changes input, then you are better of with onChange, because it gives you more flexibility. For example:
handleChange(event) {
const {name, type, value} = event.nativeEvent;
let processedData = value;
if(type==='text') {
processedData = value.toUpperCase();
} else if (type==='number') {
processedData = value * 2;
}
this.setState({[name]: processedData})
}
<TextInput name="username" type="text" value={this.state.username} onChange={this.handleChange}}>
<TextInput name="password" type="number" value={this.state.password} onChange={this.handleChange}}>
Use it like this:
<Input label='First Name' onChange={this.onChange} value={this.state.first}/>
onChange = (event) => {
const {eventCount, target, text} = event.nativeEvent;
this.setState({first:text});
};
The target attribute seems useless. It doesn't look like you can attach data attributes to react-native elements and retrieve them from the target element like you can in react because the app is not a browser.
With react, we're told it's better practice to not attach inline functions to the onChange event for performance reasons. We're supposed to use custom props or data-* attributes on the HTML element and retrieve the information from e.target inside the onChange handler.
But with react-native it seems this format of passing data is actually acceptable:
<Input
label='First Name'
onChangeText={text=>this.onChange('first',text,'anotherValueIWantToPass')}
value={this.state.first}/>
onChangeText gives you just the string as the argument for the callback.
onChange gives you the synthetic event as the argument.
Hi in my componentWillMount I set my states like this
componentWillMount(){
this.timeSheetData().then((timeSheetResponse)=>{
this.setState({comments:timeSheetResponse.comments});
this.setState({spentHours:parseInt(timeSheetResponse.hours)});
alert(this.state.spentHours);
});
});
In my view
I have the TextInput like this. I can't display the value on the TextInput but I can display the value on Text I don't know why it's happening
<TextInput keyboardType='numeric' onChangeText={(spentHours) =>this.setState({spentHours})}
value={this.state.spentHours} />
Input values need to be strings so you either need to remove parseInt in your componentWillMount method:
this.setState({ spentHours: timeSheetResponse.hours });
or in your template you need to convert the input value to a string with toString():
<TextInput
keyboardType='numeric'
onChangeText={spentHours => this.setState({ spentHours })}
value={this.state.spentHours.toString()}
/>