Apply System

The apply system handles the "Apply" button in inventories. This powers crafting (combining items into new items) and custom interactions (puzzle mechanics, item insertion, etc.).

How It Works

When a player clicks the Apply button:

The Apply button appears when an inventory has either:

• Recipes assigned to it
• A custom interactive value set

The Apply Button

The interactive field on inventory templates controls the Apply button:

The value also becomes a CSS class on the button, allowing custom styling per inventory.

Styling the Apply button:

/* Base styling for "combine" button */
.apply-button.combine {
  background-color: #4a90d9;
}

.apply-button.combine:hover {
  background-color: #3a70b9;
}

/* Set button text using ::before */
.apply-button.combine::before {
  content: "Combine";
}

Recipes

Recipes define how items transform into other items.

Recipe Template Fields

Input/Output Format

Learning Recipes

Recipes must be learned before they can be used.

Example - Learning from a book:

Crafting Flow

When the player clicks Apply with a selected recipe:

If any check fails, an appropriate notification is shown.

Recipe Selection UI

When an inventory has recipes:

Clicking a recipe automatically moves the required ingredients from party inventory to the crafting inventory.

Stacking Rules

Crafting respects item stacking:

The system calculates available space by considering:

• Slots freed by consuming ingredients
• Existing partial stacks that can be filled
• Max stack values from item templates

Custom Apply Logic

Use the inventory_apply event for custom behavior:

game.on("inventory_apply", (inventory) => {
  if (inventory.id === "puzzle_altar") {
    // Check if correct items are placed
    const gem = inventory.getFirstItemById("red_gem");
    const key = inventory.getFirstItemById("ancient_key");

    if (gem && key) {
      // Consume items
      inventory.removeItem(gem);
      inventory.removeItem(key);

      // Store result and notify
      game.getStore("puzzle").set("altar_activated", true);
      game.showNotification("The altar glows with ancient power!");
    }

    // Prevent other calls, including default crafting(if the inventory has any recipes assigned to it)
    return false; 
  }
});

Assigning Recipes to Inventories

In the inventory template:

Example - Blacksmith inventory:

The Apply button defaults to "craft" when recipes are assigned.

Events

Methods

Quick Reference

Next Steps

• Overview - Item basics and templates
• Exchange - Trading and shops