I am curious how Javet handles import/export keywords in javascript.

[FrancescoJo]

Hello. First of all, I must say thanks for maintaining this project.

I'm planning to make a small game app which supports modding capability by javascript and reached to this project today.

What I wonder is, how Javet handles import statements with relative paths. How can I inject absolute execution path into Javet before running it via methods like executeXXX? I assume that we don't need to care in most cases like every script files are on some filesystem, but what if script files are located in compressed objects like ZIP or JAR? As you know, file URI is different if it is archived, so bottom line, how could I handle script execution in that cases?

Thanks for reading in advance.

[caoccao]

Thank you for raising this good question. I haven't tested that behavior, so V8 decides what to do for now.

Here are 3 general directions I'm thinking of.

1. Javet doesn't want to step into how and where to locate resource files so that Javet leaves all the freedom to applications. For instance, if I use Spring Boot, I may want to package the default resource in jar file and override that default one by putting the resource under classpath. Of course, in order to maintain this kind of purity, Javet has to cut the dependency to any other libraries off, which is not a challenge to me.
2. Javet has already exposed ways of registering interceptors, so applications may decide how to handle the import.
3. In the future, I plan to embed Node in Javet as Node is pretty much the standard so applications may just share the same module structure between Node and Javet.

Regarding (1) + (2), I think you may leverage custom class / resource loader to achieve your goal. Yes, that implies a bit of work.

Regarding (3), I think in the future you just need to tell Javet where to locate the JS entry file along with node_modules, you are good to go.

Hope that gives you some ideas. And your input may impact Javet in the future. Thank you.

[caoccao]

I just analyzed V8 + Node source code and found dynamic import is not supported by default, unless certain amount of C++ work backing V8 up. I think it might not be worthy of supporting dynamic import in Javet because once Node was embedded, that would be resolved.

[caoccao]

Stay tuned. NodeJS integration is on the way.

[caoccao]

Finally, Javet supports latest Node.js LTS. The short answer is: Yes, you can get identical behavior that Node.js has in Javet.

The detailed answer you are looking for is at this link.

[caoccao]

I've been asked quite a few times on how long I spent embedding Node.js. Well, it took almost 3 weeks to unlock Node.js v14.16.0 for Linux and Windows.

I started from the Windows one and it was quite hard. After settling down the Windows version, I jumped into the Linux one. It was a journey full of desperation that would almost kill this project. Finally, I made it.

That may partially explain why I don't intend to support MacOS / Android by myself. Any volunteers?

[FrancescoJo]

Thanks for your devotion

[Cormanz]

Doing testing with Javet es6 modules, it works with the exception of relative paths.

I think it might not be worthy of supporting dynamic import in Javet because once Node was embedded

I really would prefer to use native ES6 with relative imports in the newer V8 without the node version (unless I have to).
In the tutorial and reference I haven't found any way to do this, do you have any advice or reference?

[Cormanz]

Sure, I'll check out the post. Also one last thing - would Javet support URL imports?

[caoccao]

Sure, I'll check out the post. Also one last thing - would Javet support URL imports?

As I mentioned before, Javet doesn't care where to load the modules. It's applications' decision.

For instance:

1. App fetches https://abc.def/ghi.js to string a
2. App compiles module with name https://abc.def/ghi.js and code a
3. App executes a script with import {...} from 'https://abc.def/ghi.js'
4. It works

It is the application which defines how to load the modules.

[Cormanz]

How do I know which files to compile beforehand? Would I need to parse each file in a folder to see which ones are importing from URLs, so I can load those manually?

[caoccao]

How do I know which files to compile beforehand? Would I need to parse each file in a folder to see which ones are importing from URLs, so I can load those manually?

Good question. That's why I asked you if you need a callback API to inject arbitrary modules when they are being imported. With that API, application doesn't need to analyze the code for dependency. Of course, application is responsible for security check. Please think it over and open an issue if that's the one you want.

[Cormanz]

I'll probably open an issue then.