Load Conditions

Load conditions decide whether a category, entry or page is loaded at all. If a load condition is not met when the book is loaded (on world load and /reload), the element is removed entirely, as if it was never defined. It is never parsed, so it cannot cause errors, e.g. due to items or recipes that do not exist.

This is different from the regular condition, which only controls whether the element is shown to a player.

Typical use cases:

• Content for optional mod integrations, using modonomicon:mod_loaded.
• Modpacks removing content via datapack, e.g. a page that shows a recipe that was removed, using modonomicon:false.

Usage

Load conditions are set via the load_condition field on category, entry or page JSONs (both file-based pages and inline pages):

"load_condition": {
    "type": "<type>",
    ... //condition specific fields
},

When a load condition is not met:

• for a category, all its entries and their pages are removed as well.
• for an entry, all its pages are removed as well.
• for a file-based page with a target, the targeted inline page in the entry JSON is removed as well. See File-based Pages.

Supported Condition Types

Only conditions that do not depend on a player or world can be used as load condition:

• modonomicon:mod_loaded
• modonomicon:true / modonomicon:false
• modonomicon:and / modonomicon:or / modonomicon:not, if all their children are supported as well.

Using any other condition type (e.g. advancement conditions) as load condition is reported as an error and the element is not loaded.

tip

For backwards compatibility the regular condition is still evaluated at load time with its historic behavior as well, so books made for older versions keep working. New content should use load_condition, which properly applies to all content types, including inline pages.

Removing Content via Datapack

To remove content of an existing book (e.g. from another mod), you do not need to override whole files. For pages, add a file-based page with a target and a failing load condition, using the same pages/ path scheme. The file only needs the target and the load condition:

data/<book-namespace>/modonomicon/books/<book>/pages/<category>/.../<entry>/<any-name>.json

{
  "id": "<page-id>",
  "load_condition": {
    "type": "modonomicon:false"
  }
}

Instead of id the page can also be targeted by anchor or index. See File-based Pages for the targeting rules.

The same works for category files (categories/<category>.json) and entry files (entries/<category>/<entry>.json) by overriding them with just a load_condition — categories and entries have no file-based patches, so those files do need to override the whole JSON.

Live samples that override and remove pages of the demo book entry modonomicon:features/file_pages: demo page files on GitHub

Datagen

Use withLoadCondition(...) on BookCategoryModel, BookEntryModel and page models:

entry.withLoadCondition(BookModLoadedConditionModel.create().withModId("theurgy"));

Custom Condition Types

Custom conditions can support load conditions by overriding BookCondition#supportsLoadTime() to return true and implementing BookCondition#testOnLoad(BookLoadConditionContext). See Custom Conditions.