Unity 5 WebGL: Communicating with external javascript from C#

Question

I'm trying to get a Unity 5 WebGL project integrated with SCORM 1.2. This involves the Unity WebGL build communicating with some external javascript.

I found this page:
https://docs.unity3d.com/Manual/webgl-interactingwithbrowserscripting.html
...which suggests placing the external js in an Assets/Plugins/WebGL folder and saving the file as a .jslib file. Here's how my temporary SCORM.jslib file looks:

var SCORM = {
    Hello: function()
    {
        window.alert("Hello, world!");
        console.log("Hello function in SCORM.jslib has been called.");
    }
}

Then, in a C# script attached to my gameObject trigger (a cube):

using UnityEngine;
using System.Collections;
using System.Runtime.InteropServices;

public class CompletionTrigger : MonoBehaviour {    

    [DllImport("__Internal")]
    private static extern void Hello();

    void Start () {

        Hello();

    }    

    void Update () {

    }
}

The problem is I'm getting an 'EntryPointNotFoundException' error at the line where 'Hello()' is called.

I've googled and searched here, but the answers seem to relate to developing C++ dlls or RoR.

Does anyone know what's causing this error? Thanks.

EDIT
I saw a comment on another page that said the error appeared only in the editor so I thought I'd run a WebGL build again. I get the following error:

Failed running "C:\Program Files\Unity\Editor\Data\PlaybackEngines\WebGLSupport/BuildTools/Emscripten_Win/python/2.7.5.3_64bit/python.exe" "C:\Program Files\Unity\Editor\Data\PlaybackEngines\WebGLSupport/BuildTools/Emscripten/emcc" @"D:/Projects/Unity 3D/Packaging Test/Assets/../Temp/emcc_arguments.resp"
stdout:
WARNING: sanity check failed to run [Errno 13] Permission denied: 'C:\\Program Files\\Unity\\Editor\\Data\\PlaybackEngines\\WebGLSupport/BuildTools/emscripten.config_sanity'
stderr:
WARNING  root: did not see a source tree above or next to the LLVM root directory (guessing based on directory of C:\Program Files\Unity\Editor\Data\PlaybackEngines\WebGLSupport/BuildTools/Emscripten_FastComp_Win\llc), could not verify version numbers match
INFO     root: (Emscripten: Running sanity checks)
WARNING  root: java does not seem to exist, required for closure compiler, which is optional (define JAVA in ~/.emscripten if you want it)
error: failure to execute js library "D:\Projects\Unity 3D\Packaging Test\Assets\Plugins\WebGL\SCORM.jslib": ReferenceError: window is not defined,,ReferenceError: window is not defined

The error message continues for a while, but the last line I've included here seems to suggest the compiler doesn't know what to do with 'window', saying it's not defined. There's also mention of a 'sanity check' in there, which seems quite apt.

Once again, if anyone has any pointers, it would be much appreciated.

Answer 1

In case anyone has the same problem, I've managed to dodge this issue:

I used the first option on that Unity Manual page instead, so now my SCORM.js file is loaded into the index.html WebGL template.

(To make a custom WebGL template, create a 'WebGLTemplates' folder in your Assets folder. Any folders in Assets/Templates containing index.html files will be available as templates in the Edit > Project Settings > Player inspector panel).

So, having added...

<script src="js/SCORM.js"></script>

...to my index.html and put SCORM.js in a folder called 'js' - adjacent to the final build index.html file, I can now call SCORM.js functions from C#, like this:

Application.ExternalCall("initialiseSCORM", "This could specify an id");

The next step will be getting SCORM information from SCORM.js, but as that page suggested, I should be able to use:

SendMessage ('MyGameObject', 'MyFunction', 'foobar');

...in SCORM.js to pass information into the Unity game.