A display holds information and ingredients for Categories to setup for.

<aside> 💡 It is also important to read Categories at the same time!

</aside>

Understanding the Display object

• getInputEntries() returns List<EntryIngredient>. This is used to resolve the relationships between stacks, and not necessarily how the category must render the display as. Each EntryIngredient is a list of possible variants of the ingredient. For example, if this method returns an oak plank, and a list of logs, it means that it requires one oak plank and any logs.
• getInputEntries(MenuSerializationContext, MenuInfo, boolean) returns List<InputIngredient<EntryStack<?>>>. This is used to resolve the list of inputs for this display, aligned for the menu. Each ingredient is provided with the corresponding slot-index, and the order of the list does not matter. This method is optional to override, learn more about display transfer here.
• getOutputEntries() returns List<EntryIngredient>. This is used to resolve the relationships between stacks, and not necessarily how the category must render the display as. Each EntryIngredient is a list of possible variants of the ingredient. For example, if this method returns an oak plank, and a list of logs, it means that it returns one oak plank and any logs.
• getRequiredEntries() returns List<EntryIngredient>. By default, this method returns the same list as getInputEntries(), but this method only affects the craftable filter, as the required items to have in the inventory to satisfy the display.
• getCategoryIndentifier() returns CategoryIndentifier<?>. This should return the identifier of the category, read Categories for more information.
• getDisplayLocation() returns Optional<ResourceLocation> (Mojmap) / Optional<Identifier>. If the backend of this display is a recipe, you should return the recipe identifier so REI knows the recipe id to allow users to copy the recipe identifier.

Implementing the Display object

Method 1: Manually implementing Display

Extend Display and override the methods.

Method 2: Use BasicDisplay

Extend BasicDisplay, in the constructor return the list of inputs, outputs and the possible display location.

For example, this is the stonecutting display:

public DefaultStoneCuttingDisplay(StonecutterRecipe recipe) {
	this(EntryIngredients.ofIngredients(recipe.getIngredients()), Collections.singletonList(EntryIngredients.of(recipe.getResultItem())),
		Optional.ofNullable(recipe.getId()));
}

public DefaultStoneCuttingDisplay(List<EntryIngredient> inputs, List<EntryIngredient> outputs, Optional<ResourceLocation> location) {
	super(inputs, outputs, location);
}

With BasicDisplay, it is super easy to create a DisplaySerializer.

BasicDisplay.Serializer.ofSimple(DefaultStoneCuttingDisplay::new)

More complex setup for BasicDisplay