So I need to make classes that implement IRecipe to use the new system?

Forge already provides those classes for you. ShapedRecipes, ShapelessRecipes, ShapedOreRecipe and ShapelessOreRecipe exist in the version of forge I've mentioned. You should however use the json recipe system as that is the suggested way of doing recipes now (since it makes it easier for the end-user to edit recipes on demand which is common nowdays and Mojang may introduce S->C json recipe sync in the future versions).

How can I use json?

Mod example:

https://github.com/McJty/RFTools/tree/1.12/src/main/resources/assets/rftools/recipes

Vanilla example:

See at %forgelibrary%/assets/minecraft/recipes.

For some reason I can't find any info on json recipe format on the official mc wiki, maybe I'm just too tired at the moment. You can try, maybe you'll have better luck. The syntax is very similar, forge just introduces a couple new types you can use. 

Here is the original gist by Lex with some examples and clarifications but it might be outdated as there were changes to the system, use at your own risk.

Edited June 21, 20178 yr by V0idWa1k3r

How can I use json files with the event?

I've found ShapedRecipes.deserialize(JsonObject), should I use this?

Just create JSON files for your recipes in the assets/<modid>/recipes directory and Forge will automatically load them. You don't need to tell it to do so.

 

I have some examples of recipe files here and the recipe/ingredient classes used by them (apart from the Vanilla/Forge ones) here.

Edited June 21, 20178 yr by Choonster

I think that you simply put your jsons in the recipes folder in your assets/modid/ folder and they just work, no registration required.

Registry event is for adding recipes via code.

 

Edit: well, as Choonster answered your first question first I'll edit my answer to relate to your new question

Edited June 21, 20178 yr by V0idWa1k3r

So, I don't need any registry events or anything?

Okay, so how about smelting recipes?

Just now, Kokkie said:

Okay, so how about smelting recipes?

 

Those haven't changed in 1.12, add them in init as you would in earlier versions.

Okay, thanks!

Actually, they aren't working D:

For my code etc. go to my github.

https://github.com/KokkieBeer/Auto-Miner/tree/master/src/main/resources/assets/am/recipes

Edited June 21, 20178 yr by Kokkie

27 minutes ago, Kokkie said:

Okay, thanks!

Actually, they aren't working D:

For my code etc. go to my github.

https://github.com/KokkieBeer/Auto-Miner/tree/master/src/main/resources/assets/am/recipes

 

There should be an error in the log telling you why your recipes failed to load.

 

You can't use "block" for ingredients/results (since Blocks don't exist in inventories), you need to use "item" with the registry name of the Block's Item form.

 

Make sure you're using a recent version of Forge, recipe loading wasn't in the first few 1.12 versions.

 

Your Git repository should contain everything necessary to build your mod, including the Gradle buildscript and wrapper. See my mod and its .gitignore file for an example of which files to include.

Edited June 21, 20178 yr by Choonster