SystemJS: custom loader to help Angular 2 to `require()` parts of RxJS if these parts have already been loaded with a single file (eg: `Rx.js`)

rxjsLoader.js

// see: https://github.com/angular/angular/issues/9359
// in case all parts of RxJS are loaded with a single file (eg: Rx.js), Angular 2 may have
// difficulties using/requiring the various parts.
// this custom loader translates requests to these parts to the already loaded Rx entity.
//
// eg: Angular:
//      require('rxjs/observable/from')  -->  Rx.Observable
//      require('rxjs/operator/concatMap')  -->  Rx.Observable.prototype
//      require('rxjs/util/EmptyError')  -->  Rx
//
// Angular will access 'rxjs/observable/from' as rxjs_observable_from.from
// so, the last part of the included module (eg: 'from') denotes the property name to access
// the required value.
SystemJS.amdDefine(SystemJS.baseURL + "rxjsLoader.js", ["rxjs"], function (Rx) {
    'use strict';

    // custom loader for RX.js to instantiate the correct value
    // see: https://github.com/ModuleLoader/es-module-loader/blob/v0.17.0/docs/loader-extensions.md
    return {
        fetch: function fetch(loadData) {
            return ""; // no fetch - "Rx" is already loaded!
        },

        translate: function translate(loadData) {
            return "";
        },

        instantiate: function instantiate(loadData) {

            // loadData.name contains the full URL
            var propertyName = loadData.name.replace(/^.*\/rxjs-parts\/(.*)$/i, "$1").replace(/\.js$/i, "");

            // if property name is not empty, evaluate and use it
            if (propertyName.length > 0 && !(/^\s*$/.test(propertyName))) {
                var parts = propertyName.split("/"),
                    targetObject = Rx
                ;

                // Angular 2 expects the return value to be an object
                // and the last part of the name to be the property of that object

                for (var i=0; i < parts.length-1; i++) {
                     var partName = parts[i],
                         upperCaseName = partName.charAt(0).toUpperCase() + partName.slice(1)
                     ;

                     // handle special case for "operator/*"
                     if (partName === "operator") {
                         return Rx.Observable.prototype;

                     } else if (targetObject[partName] !== undefined) {
                         targetObject = targetObject[partName];

                     } else if (targetObject[upperCaseName] !== undefined) {
                         targetObject = targetObject[upperCaseName];

                     } else {
                         // skip name and try with next part name. eg: "utils"
                         continue;
                     }
                }

                return targetObject;

            } else {
                // return the Rx as default
                return Rx;
            }
        }
    };
});

systemjs-config-using-custom-rx-loader.js

SystemJS.config({

    baseURL: '/',

    map: {
        "rxjs": "Rx.js"
    },
    paths: {
        "Rx.js/*": "rxjs-parts/*"
    },
    packages: {
       "rxjs-parts": {
            meta: {
                "*": {
                    loader: "rxjsLoader"
                }
            }
        }
    }
});

I had to change loader: "rxjsLoader.js" (note the .js) thanks for this btw its a bit good!!