In this tutorial you will learn different ways to make XML mods compatible and how to link existing and modded recipes, facilities and buildings with eachother.

What you'll learn

You'll learn:

How to implement your changes into existing Defs
How to fix compatibility between XML mods
How to make modded recipes and buildings interact with eachother without overwriting the base game
How to link facilities to buildings
How to add Biomes to animals for the sake of spawning them

Overwriting defs

Core defs

Don't.

Use xpath instead.

Mod defs

Template:Main Article Don't.

Use xpath instead. You can use PatchOperationFindMod or PatchOperationConditional to cleverly add your Defs and Patches.

Example

<?xml version="1.0" encoding="utf-8"?>
<Patch>
    <Operation Class="PatchOperationFindMod">
        <mods>
            <li>SomeOtherMod</li>
        </mods>
        <match Class="PatchOperationReplace">
            <xpath>/Defs/ThingDef[defName="ExampleDefFromSomeOtherMod"]/isTechHediff</xpath>
            <value>
                <isTechHediff>true</isTechHediff>
            </value>
        </match>
    </Operation>
</Patch>

Referencing defs

RecipeDef

In case your mod adds a new recipe for the Electric stove, you might think it's necessary to patch or overwrite part of its ThingDef. This is however completely unnecessary - the C# code base contains a tag which allows you to make your recipe choose which building to attach to (instead of the other way round):

<?xml version="1.0" encoding="utf-8"?>
<Defs>
	<RecipeDef>
		<defName>BakeBread</defName>
			<recipeUsers>
				<li>ElectricStove</li>
			</recipeUsers>
			<!-- more tags -->
		<!-- more tags -->
	</RecipeDef>
</Defs>

If you want your building to choose which recipes to display, you do the following:

<?xml version="1.0" encoding="utf-8"?>
<Defs>
	<ThingDef>
		<defName>BakeryOven</defName>
		<recipes>
			<li>BakeBread</li>
		</recipes>
		<!-- more tags -->
	</ThingDef>
</Defs>

The BakeBread recipe will now show up in both the BakeryOven and Electric Stove, without the mod having to modify Electric Stove's <recipes> list.

There's also the option to define the recipeUsers in the Bread ThingDef:

<?xml version="1.0" encoding="utf-8"?>
<Defs>
	<ThingDef>
		<defName>DeliciousBread</defName>
		<recipeMaker
			<recipeUsers>
				<li>BakeryOven</li>
				<li>ElectricStove</li>
			</recipeUsers>
		</recipeMakers>
		<!-- more tags -->
	</ThingDef>
</Defs>

And if all else fails, there's still xpath:

<?xml version="1.0" encoding="utf-8"?>
<Patch>
	<Operation Class="PatchOperationAdd">
		<xpath>Defs/ThingDef[defName="BakeryOven"]/recipes</xpath>
		<value>
			<li>BakeBread</li>
		</value>
	</Operation>
</Patch>

Facilities

Buildings with the "CompAffectedByFacilities" compClass can choose which facilities should link to them. In the base game it isn't used the other way round - facilities don't do this - but the C# code base has a tag for it:

<?xml version="1.0" encoding="utf-8"?>
<Defs>
	<ThingDef>
		<defName>BadIdeaShredder</defName>
		<comps>
			<li>
				<compClass>CompFacility</compClass>
				<statOffsets>
					<ResearchSpeedFactor>0.05</ResearchSpeedFactor>
				</statOffsets>
				<linkableBuildings>
					<li>ResearchBench</li>
				</linkableBuildings>
			</li>
		</comps>
		<!-- more tags -->
	</ThingDef>
</Defs>

Linking existing facilities to modded buildings is also possible by doing what existing buildings already do:

<?xml version="1.0" encoding="utf-8"?>
<Defs>
	<ThingDef>
		<defName>MyFirstWorkshop</defName>
		<comps>
			<li>
				<compClass>CompAffectedByFacilities</compClass>
				<linkableFacilities>
					<li>ToolCabinet</li>
				</linkableFacilities>
			</li>
		</comps>
		<!-- more tags -->
	</ThingDef>
</Defs>

BadIdeaShredder can now be attached to the vanilla ResearchBench, and the vanilla ToolCabinet can now be attached to MyFirstWorkshop.

Animals

If you want your animal to show up in certain biomes, you don't need patch those biomes. You can add the biomes by defName and the game will resolve the cross reference.

<Defs>
	<ThingDef>
		<defName>MyExampleAnimal</defName>
		<race>
			<wildBiomes>
				<TropicalRainforest>0.08</TropicalRainforest>
				<TemperateForest>0.09</TemperateForest>
				<BorealForest>0.09</BorealForest>
			</wildBiomes>
		</race>
		<!-- more tags -->
	</ThingDef>
</Defs>

Next up

Def Class Compatibility explains compatibility from the Def Class side of things.
Create a DLL patch continues explanations on compatibility patching and referencing existing items.

Modding Tutorials/Compatibility with defs

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