xstate/dist/assign-c3259787.esm.js

Finite State Machines and Statecharts for the Modern Web.

import { V as ProcessingStatus, R as resolveReferencedActor, c as createActor, W as cloneMachineSnapshot } from './raise-b0a4e862.esm.js';

function createSpawner(actorScope, {
  machine,
  context
}, event, spawnedChildren) {
  const spawn = (src, options) => {
    if (typeof src === 'string') {
      const logic = resolveReferencedActor(machine, src);
      if (!logic) {
        throw new Error(`Actor logic '${src}' not implemented in machine '${machine.id}'`);
      }
      const actorRef = createActor(logic, {
        id: options?.id,
        parent: actorScope.self,
        syncSnapshot: options?.syncSnapshot,
        input: typeof options?.input === 'function' ? options.input({
          context,
          event,
          self: actorScope.self
        }) : options?.input,
        src,
        systemId: options?.systemId
      });
      spawnedChildren[actorRef.id] = actorRef;
      return actorRef;
    } else {
      const actorRef = createActor(src, {
        id: options?.id,
        parent: actorScope.self,
        syncSnapshot: options?.syncSnapshot,
        input: options?.input,
        src,
        systemId: options?.systemId
      });
      return actorRef;
    }
  };
  return (src, options) => {
    const actorRef = spawn(src, options); // TODO: fix types
    spawnedChildren[actorRef.id] = actorRef;
    actorScope.defer(() => {
      if (actorRef._processingStatus === ProcessingStatus.Stopped) {
        return;
      }
      actorRef.start();
    });
    return actorRef;
  };
}

function resolveAssign(actorScope, snapshot, actionArgs, actionParams, {
  assignment
}) {
  if (!snapshot.context) {
    throw new Error('Cannot assign to undefined `context`. Ensure that `context` is defined in the machine config.');
  }
  const spawnedChildren = {};
  const assignArgs = {
    context: snapshot.context,
    event: actionArgs.event,
    spawn: createSpawner(actorScope, snapshot, actionArgs.event, spawnedChildren),
    self: actorScope.self,
    system: actorScope.system
  };
  let partialUpdate = {};
  if (typeof assignment === 'function') {
    partialUpdate = assignment(assignArgs, actionParams);
  } else {
    for (const key of Object.keys(assignment)) {
      const propAssignment = assignment[key];
      partialUpdate[key] = typeof propAssignment === 'function' ? propAssignment(assignArgs, actionParams) : propAssignment;
    }
  }
  const updatedContext = Object.assign({}, snapshot.context, partialUpdate);
  return [cloneMachineSnapshot(snapshot, {
    context: updatedContext,
    children: Object.keys(spawnedChildren).length ? {
      ...snapshot.children,
      ...spawnedChildren
    } : snapshot.children
  }), undefined, undefined];
}
/**
 * Updates the current context of the machine.
 *
 * @example
 *
 * ```ts
 * import { createMachine, assign } from 'xstate';
 *
 * const countMachine = createMachine({
 *   context: {
 *     count: 0,
 *     message: ''
 *   },
 *   on: {
 *     inc: {
 *       actions: assign({
 *         count: ({ context }) => context.count + 1
 *       })
 *     },
 *     updateMessage: {
 *       actions: assign(({ context, event }) => {
 *         return {
 *           message: event.message.trim()
 *         };
 *       })
 *     }
 *   }
 * });
 * ```
 *
 * @param assignment An object that represents the partial context to update, or
 *   a function that returns an object that represents the partial context to
 *   update.
 */
function assign(assignment) {
  function assign(_args, _params) {
  }
  assign.type = 'xstate.assign';
  assign.assignment = assignment;
  assign.resolve = resolveAssign;
  return assign;
}

export { assign as a };