react-xstate-js v2.2.0

react-xstate-js

A React interpreter for xstate that uses renderProps.

Installation

yarn add react-xstate-js

or

npm i react-xstate-js -S

Using

Example 1 - reading & changing state

import React from 'react';
import { Machine } from 'react-xstate-js';

const myMachineConfig = {
  key: 'example1',
  initial: 'step1',
  states: {
    step1: {
      on: {
        NEXT: 'step2',
      },
    },
    step2: {
      on: {
        PREVIOUS: 'step1',
        NEXT: 'step3',
      },
    },
    step3: {
      on: {
        PREVIOUS: 'step2',
      },
    },
  },
};

const MyComponent = () => (
  <Machine config={myMachineConfig}>
    {({ service, state }) => (
    <>
      <button
        type="button"
        onClick={() => service.send({ type: 'PREVIOUS' })}
      >
        previous
      </button>
      <button
        type="button"
        onClick={() => service.send({ type: 'NEXT' })}
      >
        next
      </button>
      <p>
        state:
        {' '}
        {JSON.stringify(state.value)}
      </p>
    </>
    )}
  </Machine>
);

Example 1 - TypeScript

import React from 'react';
import { 
  MachineConfig, Machine, State, Interpreter
} from 'react-xstate-js'

interface MyStateSchema {
  states: {
    step1: {}
    step2: {}
    step3: {}
  }
}

type MyEvent = { type: 'NEXT' } 
  | { type: 'PREVIOUS' }

const myMachineConfig: MachineConfig<{}, MyStateSchema, MyEvent> = {
  key: 'example1',
  initial: 'step1',
  states: {
    step1: {
      on: {
        NEXT: 'step2',
      },
    },
    step2: {
      on: {
        PREVIOUS: 'step1',
        NEXT: 'step3',
      },
    },
    step3: {
      on: {
        PREVIOUS: 'step2',
      },
    },
  },
}

const MyComponent: React.SFC = () => (
  <Machine config={myMachineConfig}>
    {({ service, state }: { service: Interpreter<{}, MyStateSchema, MyEvent>, state: State<{}, MyEvent> }) => (
      <>
        <button
          type="button"
          onClick={() => service.send({ type: 'PREVIOUS' })}
        >
          previous
        </button>
        <button
          type="button"
          onClick={() => service.send({ type: 'NEXT' })}
        >
          next
        </button>
        <p>
          state:
          {' '}
          {JSON.stringify(state.value)}
        </p>
      </>
    )}
  </Machine>
)

Example 2 - options (with actions)

import React from 'react';
import { Machine } from 'react-xstate-js';

const myMachineConfig = {
  key: 'example2',
  initial: 'step1',
  states: {
    step1: {
      on: {
        NEXT: 'step2',
      },
    },
    step2: {
      onEntry: ['myAction'],
      on: {
        PREVIOUS: 'step1',
        NEXT: 'step3',
      },
    },
    step3: {
      on: {
        PREVIOUS: 'step2',
      },
    },
  },
};

const myMachineOptions = {
  actions: {
    myAction: () => {
      console.log('myAction fired');
    },
  },
};

const MyComponent = () => (
  <Machine
    config={myMachineConfig}
    options={myMachineOptions}
  >
    {({ service, state }) => (
    <>
      <button
        type="button"
        onClick={() => service.send({ type: 'PREVIOUS' })}
      >
        previous
      </button>
      <button
        type="button"
        onClick={() => service.send({ type: 'NEXT' })}
      >
        next
      </button>
      <p>
        state:
        {' '}
        {JSON.stringify(state.value)}
      </p>
    </>
    )}
  </Machine>
);

Example 2 - TypeScript

import React from 'react';
import {
  MachineConfig, MachineOptions, Machine, State, Interpreter
} from 'react-xstate-js'

interface MyStateSchema {
  states: {
    step1: {}
    step2: {}
    step3: {}
  }
}

type MyEvent = { type: 'NEXT' }
  | { type: 'PREVIOUS' }

const myMachineConfig: MachineConfig<{}, MyStateSchema, MyEvent> = {
  key: 'example1',
  initial: 'step1',
  states: {
    step1: {
      on: {
        NEXT: 'step2',
      },
    },
    step2: {
      onEntry: ['myAction'],
      on: {
        PREVIOUS: 'step1',
        NEXT: 'step3',
      },
    },
    step3: {
      on: {
        PREVIOUS: 'step2',
      },
    },
  },
}

const myMachineOptions: MachineOptions<{}, MyEvent> = {
  actions: {
    myAction: () => {
      console.log('myAction fired');
    },
  },
};

const MyComponent: React.SFC = () => (
  <Machine 
    config={myMachineConfig}
    options={myMachineOptions}
  >
    {({ service, state }: { service: Interpreter<{}, MyStateSchema, MyEvent>, state: State<{}, MyEvent> }) => (
      <>
        <button
          type="button"
          onClick={() => service.send({ type: 'PREVIOUS' })}
        >
          previous
        </button>
        <button
          type="button"
          onClick={() => service.send({ type: 'NEXT' })}
        >
          next
        </button>
        <p>
          state:
          {' '}
          {JSON.stringify(state.value)}
        </p>
      </>
    )}
  </Machine>
)

Example 3 - context

import React from 'react';
import { 
  Machine, assign 
} from 'react-xstate-js';

const myMachineConfig = {
  key: 'example3',
  context: {
    foo: '',
  },
  initial: 'step1',
  states: {
    step1: {
      on: {
        NEXT: 'step2',
      },
    },
    step2: {
      onEntry: ['myAction'],
      on: {
        PREVIOUS: 'step1',
        NEXT: 'step3',
      },
    },
    step3: {
      on: {
        PREVIOUS: 'step2',
      },
    },
  },
};

const myMachineOptions = {
  actions: {
    myAction: assign({ foo: () => 'bar' }),
  },
};

const MyComponent = () => (
  <Machine
    config={myMachineConfig}
    options={myMachineOptions}
  >
    {({ service, state }) => (
    <>
      <button
        type="button"
        onClick={() => service.send({ type: 'PREVIOUS' })}
      >
        previous
      </button>
      <button
        type="button"
        onClick={() => service.send({ type: 'NEXT' })}
      >
        next
      </button>
      <p>
        state:
        {' '}
        {JSON.stringify(state.value)}
      </p>
      <p>
        context:
        {' '}
        {JSON.stringify(state.context)}
      </p>
    </>
    )}
  </Machine>
);

Example 3 - TypeScript

import React from 'react';
import {
  MachineConfig, MachineOptions, Machine, State, Interpreter, assign
} from 'react-xstate-js'

interface MyContext {
  foo: string
}

interface MyStateSchema {
  states: {
    step1: {}
    step2: {}
    step3: {}
  }
}

type MyEvent = { type: 'NEXT' }
  | { type: 'PREVIOUS' }

const myMachineConfig: MachineConfig<MyContext, MyStateSchema, MyEvent> = {
  key: 'example1',
  context: {
    foo: '',
  },
  initial: 'step1',
  states: {
    step1: {
      on: {
        NEXT: 'step2',
      },
    },
    step2: {
      onEntry: ['myAction'],
      on: {
        PREVIOUS: 'step1',
        NEXT: 'step3',
      },
    },
    step3: {
      on: {
        PREVIOUS: 'step2',
      },
    },
  },
}

const myMachineOptions: MachineOptions<MyContext, MyEvent> = {
  actions: {
    myAction: assign({ foo: () => 'bar' }),
  },
};

const MyComponent: React.SFC = () => (
  <Machine
    config={myMachineConfig}
    options={myMachineOptions}
  >
    {({ service, state }: { service: Interpreter<MyContext, MyStateSchema, MyEvent>, state: State<MyContext, MyEvent> }) => (
      <>
        <button
          type="button"
          onClick={() => service.send({ type: 'PREVIOUS' })}
        >
          previous
        </button>
        <button
          type="button"
          onClick={() => service.send({ type: 'NEXT' })}
        >
          next
        </button>
        <p>
          state:
          {' '}
          {JSON.stringify(state.value)}
        </p>
        <p>
          context:
          {' '}
          {JSON.stringify(state.context)}
        </p>
      </>
    )}
  </Machine>
)

Example 4 - persisting state

import React from 'react';
import {
  Machine,
} from 'react-xstate-js'

const myMachineConfig = {
  key: 'example1',
  initial: 'step1',
  states: {
    step1: {
      on: {
        NEXT: 'step2',
      },
    },
    step2: {
      on: {
        PREVIOUS: 'step1',
        NEXT: 'step3',
      },
    },
    step3: {
      on: {
        PREVIOUS: 'step2',
      },
    },
  },
}

const mySavedJSONState = `{ "actions": [], "activities": {}, "meta": {}, "events": [], "value": "step3", "event": { "type": "NEXT" }, "historyValue": { "current": "step3", "states": {} }, "history": { "actions": [], "activities": {}, "meta": {}, "events": [], "value": "step2", "event": { "type": "NEXT" }, "historyValue": { "current": "step2", "states": {} }, "history": { "actions": [], "activities": {}, "meta": {}, "events": [], "value": "step1", "event": { "type": "xstate.init" } } } }`

const mySavedState = JSON.parse(mySavedJSONState)

const MyComponent = () => (
  <Machine 
    config={myMachineConfig}
    savedState={mySavedState}
  >
    {({ service, state }) => (
      <>
        <button
          type="button"
          onClick={() => service.send({ type: 'PREVIOUS' })}
        >
          previous
      </button>
        <button
          type="button"
          onClick={() => service.send({ type: 'NEXT' })}
        >
          next
      </button>
        <p>
          state:
          {' '}
          {JSON.stringify(state.value)}
        </p>
      </>
    )}
  </Machine>
)

export default MyComponent

Example 4 - TypeScript

import React from 'react';
import {
  MachineConfig, Machine, State, Interpreter
} from 'react-xstate-js'

interface MyStateSchema {
  states: {
    step1: {}
    step2: {}
    step3: {}
  }
}

type MyEvent = { type: 'NEXT' }
  | { type: 'PREVIOUS' }

const myMachineConfig: MachineConfig<{}, MyStateSchema, MyEvent> = {
  key: 'example1',
  initial: 'step1',
  states: {
    step1: {
      on: {
        NEXT: 'step2',
      },
    },
    step2: {
      on: {
        PREVIOUS: 'step1',
        NEXT: 'step3',
      },
    },
    step3: {
      on: {
        PREVIOUS: 'step2',
      },
    },
  },
}

const mySavedJSONState = `{ "actions": [], "activities": {}, "meta": {}, "events": [], "value": "step3", "event": { "type": "NEXT" }, "historyValue": { "current": "step3", "states": {} }, "history": { "actions": [], "activities": {}, "meta": {}, "events": [], "value": "step2", "event": { "type": "NEXT" }, "historyValue": { "current": "step2", "states": {} }, "history": { "actions": [], "activities": {}, "meta": {}, "events": [], "value": "step1", "event": { "type": "xstate.init" } } } }`

const mySavedState: State<{}, MyEvent> = JSON.parse(mySavedJSONState)

const MyComponent: React.SFC = () => (
  <Machine 
    config={myMachineConfig}
    savedState={mySavedState}
  >
    {({ service, state }: { service: Interpreter<{}, MyStateSchema, MyEvent>, state: State<{}, MyEvent> }) => (
      <>
        <button
          type="button"
          onClick={() => service.send({ type: 'PREVIOUS' })}
        >
          previous
      </button>
        <button
          type="button"
          onClick={() => service.send({ type: 'NEXT' })}
        >
          next
      </button>
        <p>
          state:
          {' '}
          {JSON.stringify(state.value)}
        </p>
      </>
    )}
  </Machine>
)

export default MyComponent

API

\<Machine \/>

A React interpreter for xstate.

<Machine
  config={...}
  options={...}
>
  {({ service, state }) => (
    ...
  )}
</Machine>

Props

config: xstate machine config.

const mmyMachineConfig = {
  key: 'example1',
  initial: 'step1',
  states: {
    step1: {
      on: {
        NEXT: 'step2',
      },
    },
    step2: {
      on: {
        PREVIOUS: 'step1',
        NEXT: 'step3',
      },
    },
    step3: {
      on: {
        PREVIOUS: 'step2',
      },
    },
  },
};

options: xstate machine options.

const myMachineOptions = {
  actions: {
    myAction: () => {
      console.log('myAction fired');
    },
  },
};

savedState: xstate State.

const savedState = {
  "actions": [],
  "activities": {},
  "meta": {},
  "events": [],
  "value": "step3",
  "event": {
    "type": "NEXT"
  },
  "historyValue": {
    "current": "step3",
    "states": {}
  },
  "history": {
    "actions": [],
    "activities": {},
    "meta": {},
    "events": [],
    "value": "step2",
    "event": {
      "type": "NEXT"
    },
    "historyValue": {
      "current": "step2",
      "states": {}
    },
    "history": {
      "actions": [],
      "activities": {},
      "meta": {},
      "events": [],
      "value": "step1",
      "event": {
        "type": "PREVIOUS"
      },
      "historyValue": {
        "current": "step1",
        "states": {}
      }
    }
  }
};

Return

service: xstate interpreter.

<Machine {...} >
  {({ service }) => (
    ...
  )}
</Machine>

state: xstate state.

<Machine {...} >
  {({ state }) => (
    ...
  )}
</Machine>