javascriptreactjsxstate

Is there a way to set the state of an xstate machine in a react component in useEffect?


I have the following React.js component that needs the following:

Here is the display of the component


State Buttons


Here is what I have so far.

import React, { useEffect, useState } from 'react';
import { useParams, useHistory } from "react-router-dom";
import { createMachine } from 'xstate';
import { useMachine } from "@xstate/react";
import {MagellanButton} from "./Styles";
import 'bootstrap/dist/css/bootstrap.min.css';
import '../App.css';

const approvalMachine = createMachine({
    id: 'approve',
    initial: 'Not Submitted',
    context: {
        retries: 0
    },
    states: {
        'Not Submitted': {
            on: {
                SUBMIT: 'Pending Approval'
            }
        },
        'Pending Approval': {
            on: {
                CANCEL: 'Not Submitted',
                CHANGE: 'Change Request',
                DENIED: 'Denied',
                APPROVED: 'Approved'
            }
        },
        'Change Request': {
            on: {
                RESUBMITTED: 'Pending Approval',
                CANCEL: 'Not Submitted'
            }
        },
        Denied: {
            type: 'final'
        },
        Approved: {
            on: {
                PUBLISH: 'Published'
            }
        },
        Published: {
            type: "final"
        }
    }
});

function MagellanStateManager({id}) {
    const parameters = useParams();
    const history = useHistory()
    const [state, send] = useMachine(approvalMachine);

    useEffect(() => {
    }, []);

    return (
        <span style={{float: "right", marginTop: 8}}>
            <span className="m-form-label  ml-3">State:</span> <span>{state.value}</span>
            <MagellanButton className="ml-3" disabled={!state.nextEvents.includes('SUBMIT')} onClick={() => send('SUBMIT')}>Submit</MagellanButton>
            <MagellanButton className="ml-3" disabled={!state.nextEvents.includes('CANCEL')} onClick={() => send('CANCEL')}>Cancel</MagellanButton>
            <MagellanButton className="ml-3" disabled={!state.nextEvents.includes('CHANGE')} onClick={() => send('CHANGE')}>Change</MagellanButton>
            <MagellanButton className="ml-3" disabled={!state.nextEvents.includes('RESUBMITTED')} onClick={() => send('RESUBMITTED')}>Resubmit</MagellanButton>
            <MagellanButton className="ml-3" disabled={!state.nextEvents.includes('DENIED')} onClick={() => send('DENIED')}>Deny</MagellanButton>
            <MagellanButton className="ml-3" disabled={!state.nextEvents.includes('APPROVED')} onClick={() => send('APPROVED')}>Approve</MagellanButton>
            <MagellanButton className="ml-3" disabled={!state.nextEvents.includes('PUBLISH')} onClick={() => send('PUBLISH')}>Publish</MagellanButton>
        </span>
    )

}

export default MagellanStateManager;

Solution

  • From the comment from Taxel, I was able to find my solution. Here is the changed react element. I would appreciate any additional comments to make this even better.

    Thank You!

    import React, {useEffect, useState} from 'react';
    import { createMachine, interpret } from 'xstate';
    import {MagellanButton} from "./Styles";
    import 'bootstrap/dist/css/bootstrap.min.css';
    import '../App.css';
    
    const approvalMachine = createMachine({
        id: 'approve',
        initial: 'Not Submitted',
        context: {
            retries: 0
        },
        states: {
            'Not Submitted': {
                on: {
                    SUBMIT: 'Pending Approval'
                }
            },
            'Pending Approval': {
                on: {
                    CANCEL: 'Not Submitted',
                    CHANGE: 'Change Request',
                    DENIED: 'Denied',
                    APPROVED: 'Approved'
                }
            },
            'Change Request': {
                on: {
                    RESUBMITTED: 'Pending Approval',
                    CANCEL: 'Not Submitted'
                }
            },
            Denied: {
                type: 'final'
            },
            Approved: {
                on: {
                    PUBLISH: 'Published'
                }
            },
            Published: {
                type: "final"
            }
        }
    });
    
    function MagellanStateManager({id}) {
        const [service, setService] = useState(interpret(approvalMachine));
        const [counter, setCounter] = useState(0);
    
        useEffect(() => {
            // TODO: Add the fetch to get the stored state from the server
            const approvalService = interpret(approvalMachine);
            approvalService.start(approvalMachine.initialState);
            setService(approvalService);
            // TODO: Add dependencies for the useEffect for when identification values change
        }, []);
    
        function storeState(theEvent) {
            const newState = service.send(theEvent);
            const theState = JSON.stringify(newState);
            // TODO: Add the fetch to send the state to the server to be stored
            console.log(theState);
            setCounter(counter + 1);
        }
    
        function notEvent(theEvent) {
            if (service != null && service._state != null) {
                return !service._state.nextEvents.includes(theEvent);
            } else {
                return true;
            }
        }
    
        return (
            <span style={{float: "right", marginTop: 8}}>
                <span className="m-form-label  ml-3">State:</span> <span>{service ? service._state ? service._state.value : "" : ""}</span>
                <MagellanButton className="ml-3" disabled={notEvent('SUBMIT')} onClick={() => storeState('SUBMIT')}>Submit</MagellanButton>
                <MagellanButton className="ml-3" disabled={notEvent('CANCEL')} onClick={() => storeState('CANCEL')}>Cancel</MagellanButton>
                <MagellanButton className="ml-3" disabled={notEvent('CHANGE')} onClick={() => storeState('CHANGE')}>Change</MagellanButton>
                <MagellanButton className="ml-3" disabled={notEvent('RESUBMITTED')} onClick={() => storeState('RESUBMITTED')}>Resubmit</MagellanButton>
                <MagellanButton className="ml-3" disabled={notEvent('DENIED')} onClick={() => storeState('DENIED')}>Deny</MagellanButton>
                <MagellanButton className="ml-3" disabled={notEvent('APPROVED')} onClick={() => storeState('APPROVED')}>Approve</MagellanButton>
                <MagellanButton className="ml-3" disabled={notEvent('PUBLISH')} onClick={() => storeState('PUBLISH')}>Publish</MagellanButton>
            </span>
        )
    
    }
    
    export default MagellanStateManager;