In the angular2 5 min tutorial they use "system" as the module in the tsconfig. I have systemjs as a node_module but when trying to start my server I get System is not defined, from the first line of the compile js-file which looks like this:
System.register(['http', 'express', './config/index', 'path'], function(exports_1) {
Why is System undefined even though I have it as a node dependency?
I was trying to change it to commonjs, then the compiled js looks much simpler. But then I get errors in the angular application.
What am I missing in order for it to work with SystemJs?
Edit
I think I was bad at explaining my problem. When changing from importing modules into my server.ts file "javascript style" (var http = require('http');) to I guess "typescript style" (import * as http from 'http';) I start getting the error specified above. When doing it javascript style the compiled js looks just the same as the ts (var http = require('http');) however when doing it "typescript style" it gets compiled with modules being imported using System (the line of code specified above). So i'm getting this error when trying to start the node server and not in the browser.
I tried changing the compilerOption "module" to "commonjs" instead of "system" in tsconfig.json, doing that causes errors in the browser (this error, only the solutions doesn't seem to fit) for some weird reason so i figured i'd try with "system". But then I ran into the problem of not have System defined. So how do I get access to System when starting the node server?
It looks like you are missing reference to system.js in your index.html. Angular is meant to be run by browsers so its not enough to have it as node dependency, browser will not load it automatically. And of course do not try to run angular application on server side in node.js. What you want to do on server-side (node.js) is to run some web server that will serve content to the browser (http-server, lite-server, etc). And then open your index.html served by web server in browser that in turn will run angular2 application using system.js for module loading.
If you do have system.js referenced in index.html and you are not trying to run it on node.js server side - make sure the path is correct and it does get loaded - by using development tools of any modern browser.
Related
A Brief Backstory
I have been implementing several upgrades to an Angular 8 application such as server-side rendering, and Google Analytics. As most developers do, I would code then test then move on to the next task. Typically I use ng serve to run the application as I am developing.
With Server-side rendering, to test speed, lazy-loaded images, etc, you need to use a node express server running on a generated JS file. After building, etc, I use Node prerender (my js file is prerender.js) to see what the application will look like prerendering on the server.
When I run this command, I should not get any errors, and I know my prender file will start a local server on port 4000.
The Problem
I get errors when running a node express server that I do not get when running with ng serve I recently got an error that said:
Unhandled Promise rejection: Cannot read property 'subscribe' of undefined ; Zone: <root> ; Task: Promise.then ; Value: TypeError: Cannot read property 'subscribe' of undefined
at new ApplicationRef (C:\4towerdevelopment\dist-stage\server\main.js:45910:37)
at _createClass (C:\4towerdevelopment\dist-stage\server\main.js:37184:20)
at _createProviderInstance (C:\4towerdevelopment\dist-stage\server\main.js:37138:26)
at initNgModule (C:\4towerdevelopment\dist-stage\server\main.js:37044:32)
at new NgModuleRef_ (C:\4towerdevelopment\dist-stage\server\main.js:38176:9)
at Object.createNgModuleRef (C:\4towerdevelopment\dist-stage\server\main.js:38159:12)
at NgModuleFactory_.create (C:\4towerdevelopment\dist-stage\server\main.js:50821:25)
at C:\4towerdevelopment\dist-stage\prerender.js:29175:43
at ZoneDelegate.invoke (C:\4towerdevelopment\dist-stage\prerender.js:481:26)
at Object.onInvoke (C:\4towerdevelopment\dist-stage\prerender.js:28683:33) TypeError: Cannot read property 'subscribe' of undefined
at new ApplicationRef (C:\4towerdevelopment\dist-stage\server\main.js:45910:37)
at _createClass (C:\4towerdevelopment\dist-stage\server\main.js:37184:20)
at _createProviderInstance (C:\4towerdevelopment\dist-stage\server\main.js:37138:26)
at initNgModule (C:\4towerdevelopment\dist-stage\server\main.js:37044:32)
at new NgModuleRef_ (C:\4towerdevelopment\dist-stage\server\main.js:38176:9)
at Object.createNgModuleRef (C:\4towerdevelopment\dist-stage\server\main.js:38159:12)
at NgModuleFactory_.create (C:\4towerdevelopment\dist-stage\server\main.js:50821:25)
at C:\4towerdevelopment\dist-stage\prerender.js:29175:43
at ZoneDelegate.invoke (C:\4towerdevelopment\dist-stage\prerender.js:481:26)
at Object.onInvoke (C:\4towerdevelopment\dist-stage\prerender.js:28683:33)
The closest this gets me to figuring what actually is causing the problem is letting me know that a provider somewhere is causing this error. Looks like something should be an observable rather than a subscription. Beyond that, I guess I just start looking through my providers. My question is:
How can I force Angular to possibly throw this error when developing using ng serve?
If I can't, is there a better way to debug this current error besides combing through each provider? Or at least a way to tell what service is causing the issue?
Thank you.
UPDATE: Basic repo with problem here. I made a new angular project, made sure dependencies were up to date, installed ngUniversal per this post, and received this same Unhandled promise message when running node prerender
Verbatim I went to to the Angular cli website, made a new project (default Angular version installed was 8.3), installed Angular Universal, and tried to build. Same error message as above.
This looks like it was ApplicationRef that triggered the error, and that class is provided internally by the Angular core.
It could be failing in the constructor of the class, and there are a few calls to subscribe on Zone observables. I don't think you're going to find anything in your source code that directly relates to this error. It looks like a build configuration problem.
https://github.com/angular/angular/blob/bb52fb798c8578c461d21aee2b7623232184a5d3/packages/core/src/application_ref.ts#L562
I do not know what could possibly produce this problem, but I would start a new project with SSR and compare the differences to your current project.
Eventually, I dropped the angular 6 approach using pre-render, and went with the latest universal package. There seems to be no problem building using npm run build:ssr and serving dist/server.js in an express server. I am not sure what the problem was with the pre-render approach, but it seems to be outdated anyways. #Reactgular thanks for the feedback.
This is somewhat related to an issue I'm having with CF on IBM Cloud here. My question after playing around with the folder structures is how exactly is CF building the app when it comes to relative paths?
For example, if i have the following folder structure
when I add <script type = 'text/javascript' src = '../index.js'></script> to the index.html file, I get GET https://simple-toolchain-20190320022356947.mybluemix.net/index.js net::ERR_ABORTED 404. This error does not happen when I move index.js into the public folder and change <script type = 'text/javascript' src = 'index.js'></script>.
The problem I have then is that when I try to require() any modules when the index.js file is in a sub-directory, it returns a Require is not defined error indicating that it is not getting the module from the node_modules cache which CF is suppose to build. Requiring any files in the same sub-directory also throws the same error. This does not seem to be a problem when the require() is used in the default app.js as the application loads without any errors.
I'm relatively new to the IBM Cloud Foundry tool but I'm following the same structure as when I pushed apps via Cloud9 IDE and didn't have any such issues there. I feel I might be missing something ridiculously simple like configuration of endpoint or package.json. However, I've been searching around for days and can't seem to find a solution.
Appreciate if you have any pointers. Thanks!
Due to my lack of understanding, I was trying to use require() on the client side hence the errors. Going to figure out how to use Browserify now. ;)
I have a Node.js project written in TypeScript. In my project, I have a folder named "public" which contains the client side code & HTML and also a file named classes.ts which is supposed to be shared to the server side.
The problem is that I need to add "export" before the classes declaration in order to make them accessible in the server, but then in the browser I get this Error:
Uncaught ReferenceError: exports is not defined
I found these questions:
https://github.com/Microsoft/TypeScript/issues/5094,
Setup a Typescript project with classes shared between client and server apps?,
Share module between client and server with TypeScript,
which suggests using commonjs in the server but amd in the client. The problem with this solution is that they have 3 different projects (server, client and shared) whereas I only have one project in which I use commonjs.
Another suggestion is:
the other option, which is more convoluted and will require a post
build step to massage the code; if you can not use module loaders in
your client code, is to isolate all module dependencies in your server
code, then in the shared, they are just classes. Build the shared
files without --module, and no exports or imports, but all inside a
single namespace, say namespace MyApp { ... }; in your client code,
you include them directly, and emit using --out. in your server code,
you first emit the shared code to a single file, shared.js, and a
single .d.ts shared.d.ts, augment these with some code to export them
as a module, e.g. append exports = MyApp at the end of your shared.js
and shared.d.ts, then import them from your server code.
But I don't want to deal with updating .d.ts files all the time, and I'm also not sure it will work in one project.
Any suggestion how to make a TypeScript class accessible both in browser and server?
Any help will be profoundly appreciated!
This is absolutely possible.
I have a project containing both SPA client application that runs in browser and server running in node.js that both share common typescript classes. For all of this I have just one tsconfig.json file (I am still not sure that this is the best approach but for now it works just fine)
Here are parts of my setup:
Use modules (previously called external modules). No need for namespaces and d.ts files for your own modules.
module = "commonjs" in tsconfig.
On client side use System.js as module loader (this will solve your 'Uncaught ReferenceError: exports is not defined'). You can use angular2 5 min quickstart as reference how to setup system.js.
It works like a charm.
In my nwjs application i am using React to build my UI. Currently, React is being loaded via a <script> tag in the main file, index.html. index.html has another <script> tag which loads main.js containing code which defines and renders my React components as well as requiring (require()) a few Node modules such as "fs" and "McFly".
This all seems to be working, however when i try using another node module (react-inlinesvg) i get an error, "document is undefined".
Having looked online for help, i have come to the conclusion that React now believes that it is being run on the server? Which is odd, as before i started using the react-inlinesvg module it was happily rendering components using React.render (clientside rendering).
If you need any more context or information then please ask.
It could be that you are rendering on the server side, or also that you are rendering both sides. In the second case you could simple nest the line that is causing you error with:
if (process.env.BROWSER) {
the line causing the error
}
If the error disappears, it means that you are on the server side also!
I hope this helps...
Basically if you code is universal (or isomorphic, if you want...) with this check you can execute the code only on client side, you want to do this to use a particular style-sheet for example:
if (process.env.BROWSER) {
require("../style/main.scss");
}
Naturally if you want to do stuff server-side you can check
if (!process.env.BROWSER) {
}
if any one face this he can solve it in 2 ways:
Solution 1: if you are using nw.js 15 or above try to enable mix context mode:
in your package.json add this flag:
"chromium-args": "--mixed-context"
Solution 2: expose document to the global object using this hack:
global.document = window.document;
I am working on an AngularJS application that is delivered by a SocketStream/node.js server.
I have an AngularJS service that calls api functions on the SocketStream server and progress has been good so far.
But now the time has come to start writing the first tests and the first testing framework that came to mind is Karma/Jasmine, since this is the recommend AngularJS set up.
So far so good, but since my AngularJS modules are imported using 'require' (SocketStream's version, not require.js) and server api calls are part of the test, I need to configure Karma to load SocketStream (at least its client side).
I took a good look at 'https://github.com/yiwang/angular-phonecat-livescript-socketstream' but when I run this example I get run time errors, possibly because I have later versions of variuous dependencies installed.
I managed to get 'required' resolved by packing my SocketStream app by adding 'ss.client.packAssets()' to app.js and run 'SS_PACK=1 node app.js', but when I start karma it logs an error message saying:
'Chrome 23.0 (Linux) ERROR
Uncaught TypeError: undefined is not a function
at /the...path/client/static/assets/app/1368026081351.js:25'
'1368026081351.js' is the SocketStream packed assets file. If I don't load it the error message is something like 'require is undefined', so my best guess is that the error is happening somewhere inside the SocketStream require code. Also because I run karma in DEBUG mode and can see all the files being served.
I have been trying different approaches as to find out what is happening but to now avail. So my questions are:
Is anybody else successfully testing AngularJS/SocketStream using Karma?
Does anybody have any suggestions as to how I can fix, or at least debug this problem?
Are there any alternatives/better solutions?
Time to answer, sort of, my own question:
Sort of, because I came to the conclusion that Karma and node.js/SocketStream have a lot of overlap, so I decided to see if I can omit Karma altogether and deliver the Jasmine testing platform through SocketStream. It turns out that that is possible and here's how I did it:
I defined a new SocketStream route and client in my 'app.js' file:
ss.client.define( 'test', {
view: 'SpecRunner.html',
css: ['libs/test'],
code: ['libs', 'tests', 'app'],
tmpl: 'none'
});
ss.http.route( '/test', function(req, res) {
res.serveClient( 'test' );
});
I downloaded jasmine-standalone-1.3.1.zip and copied 'SpecRunner.html' to the 'client/views' folder. I then edited it to make it load AngularJS and all SocketStream client files, like all other views:
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.0.6/angular.min.js"></script>
<script src="//ajax.googleapis.com/ajax/libs/angularjs/1.0.6/angular-resource.min.js"></script>
<SocketStream/>
I removed the 'script' tags that import the sample source files ( 'Player.js' and 'Song.js' ) and specs but let the last 'script' block in place unmodified.
I then created a new folder inside 'client/css/libs' called 'test' and copied 'jasmine.css' in there unmodified.
Then I copied 'jasmine.js' and 'jasmine-html.js' renamed to '01-jasmine.js' and '02-jasmine-html.js' but otherwise unmodified, into '/client/code/libs'.
Now Jasmine is in place and will be invoked by using the '/test' route. The slightly unsatisfactory bit is that I haven't found an elegant place to store my spec files. They only work so far if I place them inside the 'libs' folder. Anywhere else and they are served by SocketStream as modules and are not run.
But I can live with that for now. I can run Jasmine tests without having to configure a special Karma setup.