React Native : update context throw "Cannot update during an existing state transition"

Question

I have a react native app and i'm trying to update a Date in a custom context.

ThemeContext

export const ThemeContext = React.createContext({
    theme: 'dark',
    toggleTheme: () => { },
    date: new Date(),
    setDate: (date: Date) => { } 
});

Basic context with the date and the function to update it

App.tsx

export default class App extends React.Component {

  constructor(props) {
    super(props);

    this.state = {
      theme: 'dark',
      date: new Date()
    };
  }

  render() {
    const { theme, date } = this.state;
    const currentTheme = themes[theme];

    const toggleTheme = () => {
      const nextTheme = theme === 'light' ? 'dark' : 'light';
      this.setState({ theme: nextTheme });
    };

    const setDate = (date: Date) => {
      // ERROR is raised HERE
      this.setState({date: date});
    }

    return (
      <>
        <IconRegistry icons={EvaIconsPack} />
        <ThemeContext.Provider value={{ theme, toggleTheme, date, setDate }}>
          ...
        </ThemeContext.Provider>
      </>
    );
  }
}

I simply hava a state with a Date and create a setDate function. I wrapped my app into the context provider.

Picker

class PickerContent extends React.Component<{}, ContentState> {
    static contextType = ThemeContext;

    constructor(props: {} | Readonly<{}>) {
        super(props);
        let currentMode = 'date';
        let show = false;

        if (Platform.OS === 'ios') {
            currentMode = 'datetime';
            show = true;
        }

        this.state = {
            date: new Date(),
            mode: currentMode,
            show: show
        };
    }

    setMode(currentMode: string) {
        this.setState({ mode: currentMode, show: true });
    };

    onChange(_event: any, selectedDate: Date) {
        const currentDate = selectedDate || this.state.date;
        // I update the context here
        this.context.setDate(currentDate);
        
        this.setState({date: currentDate, show: Platform.OS === 'ios'})
    }

    render() {
        const {show, date, mode } = this.state;
        const color = 'dark';

        return (
            <>
            ...
            {show && <DateTimePicker
                ...
                onChange={(event, selectedDate) => this.onChange(event, selectedDate)}>
        </DateTimePicker>}</>
        )
    }
}

I use the lib 'DateTimePicker' to choose a date and bind the onChange to update the context. This picker is on a modal.

So the warning appears when the onChange function of DateTimePicker is trigger. The error is on the setState of App.tsx (in setDate)

Warning: Cannot update during an existing state transition (such as within 'render'). Render methods should be a pure function of props and state.

Would you know how to correct this error?

EDIT :

I was using a Modal component from the UI Kitten library. I switch to the react native Modal and the error is gone. It seems that the error comes from the Library. SORRY

thank you in advance for your help, Sylvain

Answer 1

I edited my question. The error finally seems to come from the library used (ui kitten).