Generated by XState Viz: https://xstate.js.org/viz

machine.js

  // Available variables:
  // - Machine
  // - interpret
  // - assign
  // - send
  // - sendParent
  // - spawn
  // - raise
  // - actions
  // - XState (all XState exports)
  
const forms = [
  'name',
  'email',
  'phone',
  'website',
  'contacts',
  'employees',
  'longevity',
  'objective',
  'password',
  'confirm',
];

const getNextForm = (context, forms, currentForm) => {
    let currentIndex = -1;

    if (currentForm) {
        currentIndex = forms.indexOf(currentForm);
    }

    return forms
    .filter((_, index) => index > currentIndex)
    .find((form) => {
        return !context.data.hasOwnProperty(form);
    }) || null;
};

const getBackForm = (context, forms, currentForm) => {
    let currentIndex = forms.length;

    if (currentForm) {
        currentIndex = forms.indexOf(currentForm);
    }

    return forms
    .filter((_, index) => index < currentIndex)
    .reverse()
    .find((form) => {
        return !context.data.hasOwnProperty(form);
    }) || null;
};

const context = {
  currentForm: null,
  data: {
    email: '[email protected]',
    employees: 10
  }
};

const freeTrialMachine = Machine({
  id: 'freeTrial',
  initial: 'idle',
  context,
  states: {
    idle: {
      on: {
        '': [{
          target: 'form',
          actions: ['init']
        }]
      }
    },
    form: {
      on: {
        BACK: [{
          target: 'form',
          cond: 'hasBack',
          actions: [assign({
            currentForm: (context) => getBackForm(context, forms, context.currentForm)
          })]
        }],
        NEXT: [
          {
            target: 'form',
            cond: 'hasNext',
            actions: [assign({
              currentForm: (context) => getNextForm(context, forms, context.currentForm)
            })]
          },
          {
            target: 'confirm',
            actions: [assign({
              currentForm: (context) => getBackForm(context, forms)
            })]
          }
        ]
      }
    },
    confirm: {
      on: {
        BACK: [{
          target: 'form',
          actions: [assign({
            currentForm: (context) => getBackForm(context, forms)
          })]
        }]
      }
    }
  }
}, {
  actions: {
    init: assign({
      currentForm: (context) => {
        return getNextForm(context, forms);
      }
    })
  },
  guards: {
    hasBack: (context) => !!getBackForm(context, forms, context.currentForm),
    hasNext: (context) => !!getNextForm(context, forms, context.currentForm)
  }
});