uniIM/node_modules/systemjs/dist/extras/named-register.js

(function () {

  /*
   * SystemJS named register extension
   * Supports System.register('name', [..deps..], function (_export, _context) { ... })
   *
   * Names are written to the registry as-is
   * System.register('x', ...) can be imported as System.import('x')
   */
  (function (global) {
    var System = global.System;
    setRegisterRegistry(System);
    var systemJSPrototype = System.constructor.prototype;
    var constructor = System.constructor;
    var SystemJS = function () {
      constructor.call(this);
      setRegisterRegistry(this);
    };
    SystemJS.prototype = systemJSPrototype;
    System.constructor = SystemJS;

    var firstNamedDefine, firstName;

    function setRegisterRegistry(systemInstance) {
      systemInstance.registerRegistry = Object.create(null);
      systemInstance.namedRegisterAliases = Object.create(null);
    }

    var register = systemJSPrototype.register;
    systemJSPrototype.register = function (name, deps, declare, metas) {
      if (typeof name !== 'string')
        return register.apply(this, arguments);
      var define = [deps, declare, metas];
      this.registerRegistry[name] = define;
      if (!firstNamedDefine) {
        firstNamedDefine = define;
        firstName = name;
      }
      Promise.resolve().then(function () {
        firstNamedDefine = null;
        firstName = null;
      });
      return register.apply(this, [deps, declare, metas]);
    };

    var resolve = systemJSPrototype.resolve;
    systemJSPrototype.resolve = function (id, parentURL) {
      try {
        // Prefer import map (or other existing) resolution over the registerRegistry
        return resolve.call(this, id, parentURL);
      } catch (err) {
        if (id in this.registerRegistry) {
          return this.namedRegisterAliases[id] || id;
        }
        throw err;
      }
    };

    var instantiate = systemJSPrototype.instantiate;
    systemJSPrototype.instantiate = function (url, firstParentUrl, meta) {
      var result = this.registerRegistry[url];
      if (result) {
        this.registerRegistry[url] = null;
        return result;
      } else {
        return instantiate.call(this, url, firstParentUrl, meta);
      }
    };

    var getRegister = systemJSPrototype.getRegister;
    systemJSPrototype.getRegister = function (url) {
      // Calling getRegister() because other extras need to know it was called so they can perform side effects
      var register = getRegister.call(this, url);

      if (firstName && url) {
        this.namedRegisterAliases[firstName] = url;
      }
      var result = firstNamedDefine || register;
      firstNamedDefine = null;
      firstName = null;
      return result;
    };
  })(typeof self !== 'undefined' ? self : global);

})();