In my react native file, I am trying to pass down a function to a child component in my static navigationOptions
but it keeps on saying undefined is not a function(evaluating'_this.props.onUpdate(e.target.value)')
I am trying to pass a the value from the text input to the parent component but it brings the error above please what am I doing wrong,
class Child extends React.Component {
constructor(props) {
super(props);
this.state = {
search: ""
}
}
handleChange = (e) => {
this.props.onUpdate(e.target.value);
this.setState({search: e.target.value});
};
render() {
return (
<TextInput placeholder="Search for your herbs by name,type..." value={this.state.search} onChange={this.handleChange}
underlineColorAndroid={'transparent'}
style={BackStyles.textBox}/>
);
}
}
PARENT COMPONENT
export default class Parent extends React.Component {
Update = (val) => {
this.setState({
search: val
});
let db = SQLite.openDatabase({
name: 'test.db',
createFromLocation: "~Herbo.db",
location: 'Library'
}, this.openCB, this.errorCB);
db.transaction((tx) => {
tx.executeSql("SELECT * FROM data where name like '" + this.state.search + "' ", [], (tx, results) => {
console.log("Query completed");
var len = results.rows.length;
for (let i = 0; i < len; i++) {
let row = results.rows.item(i);
this.setState(prevState => ({
record: [...prevState.record, row],
pressed: [...prevState.pressed, false]
}));
console.log(`Record: ${row.name}`);
//this.sleep(2);
//this.setState({record: row});
}
this.setState({loader: false})
});
});
};
static navigationOptions = ({navigation, navigationOptions}) => {
const {params} = navigation.state;
return {
headerTitle: <Child onUpdate={this.Update}/>,
};
};
constructor(props) {
super(props);
this.state = {
record: [],
header: null,
loader: true,
pressed: {},
ar: [],
search: ''
};
let db = SQLite.openDatabase({
name: 'test.db',
createFromLocation: "~Herbo.db",
location: 'Library'
}, this.openCB, this.errorCB);
db.transaction((tx) => {
tx.executeSql('SELECT * FROM data', [], (tx, results) => {
console.log("Query completed");
var len = results.rows.length;
for (let i = 0; i < len; i++) {
let row = results.rows.item(i);
this.setState(prevState => ({
record: [...prevState.record, row],
pressed: [...prevState.pressed, false]
}));
console.log(`Record: ${row.name}`);
//this.sleep(2);
//this.setState({record: row});
}
this.setState({loader: false})
});
});
}
A static
method doesn't have access to an instance's this
, so when you do:
static navigationOptions = ({navigation, navigationOptions}) => {
const {params} = navigation.state;
return {
headerTitle: <Child onUpdate={this.Update}/>,
};
};
the this.Update
is undefined
. So when you do this.props.onUpdate(e.target.value);
it is calling undefined(e.target.value)
, and undefined
is not a function.
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