Add mod loading from maven-style repository

[dscalzi]

Premise:
I have a repository of mods stored maven-style which can be used throughout many different launch configurations. I want to pass the maven identifiers to the mod loader so that it only loads the mods I specify. The loader needs two things:

1. The path to the maven root: ex. C:/repo
2. A list of maven identifiers: ex. com.author:mymod:1.1.1;com.author2:anothermod:4.1.2

This feature is supported by other mod loaders. In my opinion the implementation for fabric should look like Forge's 1.13+ system. The fabric implementation should take input from a file so that the cli length limit is not exceeded when loading a large number of mods.

1. Forge 1.13+ [1.13.2] Feature Request: --modListFile equivalent MinecraftForge/MinecraftForge#5495 (comment)
2. Forge 1.12- https://github.com/MinecraftForge/FML/wiki/New-JSON-Modlist-format
3. Liteloader http://develop.liteloader.com/liteloader/LiteLoader/issues/34

If more information is required, please let me know. Looking to add fabric support to a popular launcher I maintain and this would be a prerequisite.

[modmuss50]

Passing all the mods over the command line might not be ideal solution as I believe (please prove me wrong) some OS's have a max lenght of a command line.

I do see the uses of being able to run with specific mod jars from elsewhere.

[Scotsguy]

On Windows, commandlines can be up to 8191 characters, Linux has limits around the 2MiB range (according to xargs --show-limits on my machine)

[dscalzi]

I havent had a problem with the command line only interface for forge 1.13, but granted there are not many large modpacks available so it could be a potential issue in the future.

[jordanamr]

A path to a json file providing the maven identifiers works too.

[ydainna]

indeed it would be good

[Yousinski]

It would be really cool

[modmuss50]

Im failing to see the benfit of taking in mods maven sytle? Why not just a list of paths?

[jordanamr]

Im failing to see the benfit of taking in mods maven sytle? Why not just a list of paths?

This make it so launchers and/or toolsets can have a local maven-like repo for caching purposes I guess ?

[jordanamr]

It is actually useful for a launcher with multiple public modpacks, instead of redownloading the mods that are present in different modpacks, the launcher just maintains a maven-like repo in it's folder and then check if a mod is already in cache instead of redownloading it for each modpack that have that same mod. This also makes instance reinstallation way quicker

[modmuss50]

The launcher could still do that, why does the loader need to enforce a maven style dir structure when it could just take in a list of paths to jars (that could stored in what ever way the launcher intended)

[jordanamr]

It does not need to be enforced, it could support more ways of loading mods from a different folder, I am just seeing that the Forge --fml.mavenRoots and --fml.mods works very good.

For example, using the fml style:
--altModsDir "C:\Blabla\repo" --altMods com.author:mymod:1.1.1;com.author2:anothermod:4.1.2

Using a list of paths to jars (considering the loader will scan subfolders too, to make any folder structure works):
--altModsDir "C:\Blabla\repo" --altMods mymod-1.1.1+build.1-1.16.1.jar;anothermod-4.1.2+build.2-1.16.1.jar

Is this what you meant?
The only issue I see is that maven identifiers are smaller than having the whole file name.

[Player3324]

I am not a fan of the maven layout either, it should suffice to specify a path list, absolute or relative to the working dir. Something like --fabric-add-mods /some/path/to/MyMod.jar:/some/path/to/MyOtherMod.jar (note the os specific path separator). This could be complemented by --fabric-args-file /some/file.txt to pass additional program args (fabric or mc) beyond the os limit.

Alternatively you could just hard- or symlink the mods into mods/, which would be quite a bit nicer for the users to handle imo.

[jordanamr]

Alternatively you could just hard- or symlink the mods into mods/, which would be quite a bit nicer for the users to handle imo.

I really don't like this idea... I approve the rest of your comment tho

[modmuss50]

I think having both methods of passing paths stright over the command line, or via a text file should be fine. The symlink stuff is already there (fixed in 0.9) so can be used if you want to.