bpmn-elements/src/eventDefinitions/CancelEventDefinition.js

Executable workflow elements based on BPMN 2.0

import { cloneContent, shiftParent } from '../messageHelper.js';

const kCompleted = Symbol.for('completed');
const kExecuteMessage = Symbol.for('executeMessage');

export default function CancelEventDefinition(activity, eventDefinition) {
  const { id, broker, environment, isThrowing } = activity;
  const type = eventDefinition.type;

  this.id = id;
  this.type = type;
  this.reference = { referenceType: 'cancel' };
  this.isThrowing = isThrowing;
  this.activity = activity;
  this.environment = environment;
  this.broker = broker;
  this.logger = environment.Logger(type.toLowerCase());
}

Object.defineProperty(CancelEventDefinition.prototype, 'executionId', {
  get() {
    return this[kExecuteMessage]?.content.executionId;
  },
});

CancelEventDefinition.prototype.execute = function execute(executeMessage) {
  return this.isThrowing ? this.executeThrow(executeMessage) : this.executeCatch(executeMessage);
};

CancelEventDefinition.prototype.executeCatch = function executeCatch(executeMessage) {
  this[kExecuteMessage] = executeMessage;
  this[kCompleted] = false;

  const executeContent = executeMessage.content;
  const { executionId, parent } = executeContent;
  const parentExecutionId = parent.executionId;

  const broker = this.broker;

  this._debug('expect cancel');

  broker.subscribeTmp('api', `activity.#.${parent.executionId}#`, this._onApiMessage.bind(this), {
    noAck: true,
    consumerTag: `_api-${executionId}`,
  });

  const expectRoutingKey = `execute.cancelled.${executionId}`;
  broker.subscribeOnce('execution', expectRoutingKey, this._onCatchMessage.bind(this), {
    consumerTag: `_onattached-cancel-${executionId}`,
  });

  broker.publish(
    'execution',
    'execute.expect',
    cloneContent(executeContent, {
      pattern: 'activity.execution.cancel',
      exchange: 'execution',
      expectRoutingKey,
    })
  );

  const waitContent = cloneContent(executeContent, {
    executionId: parentExecutionId,
    condition: this.condition,
    expect: 'cancel',
  });
  waitContent.parent = shiftParent(parent);

  broker.publish('event', 'activity.wait', waitContent);
};

CancelEventDefinition.prototype.executeThrow = function executeThrow(executeMessage) {
  const executeContent = executeMessage.content;
  const { executionId, parent } = executeContent;

  this.logger.debug(`<${executionId} (${this.activity.id})> throw cancel`);

  const broker = this.broker;
  const cancelContent = cloneContent(executeContent, {
    executionId: parent.executionId,
    state: 'throw',
  });
  cancelContent.parent = shiftParent(parent);

  broker.publish('event', 'activity.cancel', cancelContent, { type: 'cancel' });

  return broker.publish('execution', 'execute.completed', cloneContent(executeContent));
};

CancelEventDefinition.prototype._onCatchMessage = function onCatchMessage(_, message) {
  const content = message.content;
  this._debug(`cancel caught from <${content.id}>`);
  return this._complete(content.message);
};

CancelEventDefinition.prototype._complete = function complete(output) {
  this[kCompleted] = true;
  this._stop();
  this._debug('completed');
  const content = cloneContent(this[kExecuteMessage].content, {
    output,
    state: 'cancel',
  });
  return this.broker.publish('execution', 'execute.completed', content);
};

CancelEventDefinition.prototype._onApiMessage = function onApiMessage(routingKey, message) {
  switch (message.properties.type) {
    case 'discard': {
      this[kCompleted] = true;
      this._stop();
      const content = cloneContent(this[kExecuteMessage].content);
      return this.broker.publish('execution', 'execute.discard', content);
    }
    case 'stop': {
      this._stop();
      break;
    }
  }
};

CancelEventDefinition.prototype._stop = function stop() {
  const broker = this.broker,
    executionId = this.executionId;
  broker.cancel(`_onattached-cancel-${executionId}`);
  broker.cancel(`_api-${executionId}`);
};

CancelEventDefinition.prototype._debug = function debug(msg) {
  this.logger.debug(`<${this.executionId} (${this.activity.id})> ${msg}`);
};