Call IDJS script from HTML file

Where your HTML Page will be loaded -

1. Is it Web Browser ?

2. CEP Panel 

3. UXP 

If it is CEP or UXP then it should be a straight forward task as these UI is loaded by InDesign and your scripts will work.

But if your HTML is loaded on web browser then there is no way you can run InDesign Scripts. This is because of security reasons of web browser and you can't access other system files/programs.

But still there is a workaround but that will require more work -

1. Create InDesign C++ Plugin that exposes REST API.

2. Then from the web browser, you can call InDesign REST API and passing the script and C++ Plugin can execute your script.

3. Only drawback is that you can't launch InDesign from web browser. But atleast, you will be able to detect if InDesign is running or not by calling REST API.

It sounds like you are just trying to make a panel for indesign since they are based in html? If so, this is basically what a UXP or CEP plugin does. From my experience CEP plugins will not run IDJS scripts. With the UXP plugin, it should be the same code, it just does not need to be called an idjs. You can just call it a js. If you are trying to run it from a web browser onto the same computer, write a plugin instead. If you are trying to run it through a web browser on another computer, that does not sound legal.

In theory you can build jsx and run it from python. At least 10 years ago it worked. On windows.

import win32com.client
from win32com.client import Dispatch

app = win32com.client.dynamic.Dispatch('Indesign.Application')

def foo(param):
    app.DoScript(' some jsx code to which you can pass a parameter like param = % ' % param,1246973031)

I might be wrong but I don't think you can by the sole construction of an idjs script from an HTML Page. idjs scripts will basically be executed on demand (typically by the user). So your puzzle is missing a piece, i.e. a listener that reacts from the html call and run something.

What you can do at the moment is:

- Wait for UXP plugins and see if they offer some kind of "webhook" that you can use to activate the idjs script on demand.

- Work with CEP plugins. Those can easily set a webhook. But those work typically with ExtendScript. So you could either work with ExtendScript scripts, or have one that will run the idjs script (but the latter I never tried).

- Have some process of yours that catches requests and run InDesign from command line: https://stackoverflow.com/questions/37320580/how-to-execute-an-indesign-extendscript-from-command-line but I am not sure that can work with idjs file (nor the whole thing to be frankly honest).

- Use some whatever code (VB?) that both can receive http requests and drive InDesign.

My personal take at the moment would be the CEP plugin. But be aware you are at legal risk here. If the person that clicks on the HTML page that runs the idjs script is not the InDesign License owner, you are infringing Adobe InDesign's EULA. Or you need InDesign Server.