Migrating from v0.1.0 to v0.5.0

Rewriting JSON merge files

In v0.5.0, the system for merging into JSON files was fundamentally reworked. Any mods which used this system previously need to refactor these files in order to work properly.

In your mod's _merge folder, look for any json files and rewrite their contents.

// This is the format used by older versions of the game.
{
    "merge": [
        // Set `data.difficulty` to "super_hard"
        {
	        "target": "data.difficulty",
	        "payload": "super_hard"
	    },
        // In the second element of the `data.nested.enemies` array, set `weapon` to "minigun"
	    {
	        "target": "data.nested.enemies[1].weapon",
	        "payload": "minigun"
	    }
    ]
}

// This is the format which will be used starting with v0.5.0.
[
  { "op": "replace", "path": "/playData/characters/opponent", "value": "monster" }, // Replace the value of opponent with monster.
  { "op": "add", "path": "/playData/characters/girlfriend", "value": "nene" }, // Add a new key girlfriend with the value Nene.
  { "op": "add", "path": "/playData/difficulties/1", "value": "funky" }, // Add a new value funky to the difficulty array, after easy
  { "op": "add", "path": "/playData/difficulties/-", "value": "expert" }, // Add a new value expert to the end of the difficulty array.
  { "op": "remove", "path": "/playData/garbageValue" }, // Remove the key garbageValue from the data entirely
  { "op": "test", "path": "/playData/garbageValue", "value": 37 } // Test that a given value is in the JSON. If this operation fails, the patches will be rejected.
]

More information about this new system can be found at Merging Files.

Removal of Flixel UI

Flixel UI is a library used for developing creating UI elements and managing UI events in HaxeFlixel. In the past, this was used to power the UI of the Chart Editor, but the development team regularly found the library to be frustrating to use, and eventually switched to HaxeUI for most of its user interfaces.

In Friday Night Funkin' v0.5.0, the last places that the game used this library were refactored, and the game now exclusively uses a combination of manual sprite placement and HaxeUI for its user interfaces. As a result, Flixel UI was removed as a dependency.

Any mods which utilized functions and classes provided by Flixel UI may need refactoring to compensate.

Updating the API version

Once all the migration steps above have been performed, the last step is to modify your mod's API version string. In your mod's _polymod_meta.json file, locate the "api_version" property and set it to "0.5.0".

{
    // ...

    // Change this value from "0.1.0" to "0.5.0"
    "api_version": "0.5.0",

    // ...
}

NOTE: For versions of Friday Night Funkin' between v0.3.0 and v0.4.1, the modding system always looked for "0.1.0" for the api_version and refused to load the mod in all other cases. With the v0.5.0 update, this version will now change to match the game version with every update, but only breaking changes will forcibly disable mods. Those breaking changes will be documented on this page.