1.12 Recipe enhancements

1-THOUGHTS

Basic loading.
To be done on ServerInit. This means things will load multiple times on the client.
  Benifits:
    Allows us to just nuke the custom recipes every server init
    Allows us to have save leve overrides.
    Primes us for syncing recipe types/contents S->C {Not gunna happen in 1.12, but I expect Mojang to work twards this in 1.13+}
  Cons:
    Increases single player server load time. No known stats at the moment but shouldn't be TO bad
    
Loading Process:
  BootStrap: Vanilla loads their internal recipes, we'll freeze this registry and revert to it at the beginning of ServerInit
  Gather Factories:
    Gather a list of IRecipe, and Ingredient factories. 
    Loop through all mod jars/directories and load /assets/MODID/recipes/_factories.json
    Names will automatically be prefixed with modid domains. Error if name contains : to dissallow overriding other's factories
  Gather Constants:
    Done as a second pass to allow modders to depend on other mods ingredient factories
    Loop through all mods, loading /assets/MODID/recipes/_constants.json
    Add to a central dictionary as modid:name, so mods can't overlap eachother. Again, error if people try to overwrite other's    
  Load jsons from Mod Jars:
    Loop through all mods, loading /assets/MODID/recipes/[!_factories && !_constants].json
    Register to central regirsty as modid:jsonFileName like vanilla does
  Fire RegistryEvent.Register<IRecipe>:
    Fire code event to allow people to create recipes in code?
  Loading from modpack/config folder?
    Check Forge config for a 'recipes_folder', or explicitly check GameDir/custom_recipes and load all recipes there.
    Loads from all asset domains, automatically skipping the ones that do not match a loaded modid.
    This should behave the same as loading from a single jar file.
    Should we add a global FACTORIES/CONSTANTS json?
  Loading from world folder?
    Same as loading from modpacks folder but happens afterwords so that worlds override both modpacks and jars.

Conditions:
  Simple conditions to determine if we should load the recipe, or set the constant. 
  All entries must return true.
  Allow custom condition types defined in FACTORIES?
  Types to add:
    mod_loaded: modid
    item_exists: itemname
    not: [conditions] -- Inverts a condition, can be nested
    or: condition1, condition2
    

_constants.json

[
  {
    "conditions": [
      {
        "type": "mod_loaded",
        "mod": "minecraft"
      }
    ],
    "name" : "PLANKS",
    "ingredient" : {
      "type" : "ore_dict",
      "ore" : "planks"
    }
  },
  {
    "conditions": [
      {
        "type": "mod_loaded",
        "mod": "xycraft"
      }
    ],
    "name": "PLANKS",
    "ingredient" : {
      "item" : "xycraft:planks"
    }
  },
  {
    "name": "OAK_OR_SPRUCE",
    "ingredient": [
      {
        "item": "minecraft:log",
        "data" : 0
      },
      {
        "item": "minecraft:log",
        "data" : 2
      }
    ],
  },
  {
    "name": "MIXED",
    "ingredient": [
      {
        "type": "ore_dict",
        "ore": "stick"
      },
      {
        "item": "minecraft:torch"
      }
    ]
  },
  {
    "name": "PigEgg",
    "ingredient": {
      "type": "itemstack_nbt",
      "item": "minecraft:mobegg",
      "nbt": {
        "entityId": "pig"
      }
    }
  }
]

_factories.json

{
  "ingredients" : {
    "ore_dict": "net.minecraftforge.oredict.OreIngredientFactory",
    "itemstack_nbt": "net.minecraftforge.util.NBTIngredientFactory",
  },
  "recipes" : {
    "shapeless_ore" : "net.minecraftforge.oredict.ShapelessOreRecipeFactory",
    "shaped_ore" : "net.minecraftforge.oredict.ShapedOreRecipeFactory"
  }
}

recipe.json

{
  "conditions": [
    {
      "type": "mod_loaded",
      "mod": "minecraft"
    }
  ],
  "type": "minecraft:crafting_shaped",
  "group": "random_things",
  "pattern": [
    "###",
    "XXX"
  ],
  "key": {
    "#": {
      "item": "#PLANKS"
    },
    "X": [
      {
        "item": "#PLANKS"
      },
      {
        "item": "#MIXED",
      },
      {
        "item": "minecraft:planks",
        "data": 2
      }
    ]
  },
  "result": {
    "item": "minecraft:bed",
    "data": 15
  }
}

I actually made a different recipes format as well; perhaps you could look into it, it may be of use to you too.
https://github.com/FVbico/MinecraftData/tree/master/minecraft/assets/server/recipes

alright, RegistryEvent you are my friend

Thanks for leaving RegistryEvent option :P

Don't expect it as of 1.13, Its only in because I know people will bitch if its removed directly.
This is a first round of the json format. Its not perfect but its functional for 99% of use cases.

i might be a bit late, but is there a way to set the amount of results? (e.g pumpkin -> pumpkin seeds)

Is there any update on the correct procedure for removing a vanilla recipe in 1.12?