vtils/utils/signal.js

一个面向业务的 JavaScript/TypeScript 实用程序库。

/**
 * 信号。
 */
export function signal() {
  var value;
  var isOk = false;
  var error;
  var isFail = false;
  var $resolve = [];
  var $reject = [];
  var setValue = function setValue(_value) {
    value = _value;
    if ($resolve.length) {
      $resolve.forEach(function (resolve) {
        return resolve(value);
      });
      $resolve.length = 0;
      $reject.length = 0;
    }
    isOk = true;
    isFail = false;
  };
  var throwError = function throwError(_error) {
    error = _error;
    if ($reject.length) {
      $reject.forEach(function (reject) {
        return reject(error);
      });
      $resolve.length = 0;
      $reject.length = 0;
    }
    isOk = false;
    isFail = true;
  };
  var getValue = function getValue() {
    if (isOk) {
      return Promise.resolve(value);
    }
    if (isFail) {
      return Promise.reject(error);
    }
    return new Promise(function (resolve, reject) {
      if (isOk) {
        return resolve(value);
      }
      if (isFail) {
        return reject(error);
      }
      $resolve.push(resolve);
      $reject.push(reject);
    });
  };
  return {
    set: setValue,
    get: getValue,
    throw: throwError
  };
}