minecraft-bedrock-json-schemas/source/resource/ui/general/item_ref.json

{
  "$schema": "http://json-schema.org/draft-07/schema",
  "anyOf": [
    {
      "title": "Element reference",
      "description": "A reference to an element: using the following syntax: [element_name]@[namespace_reference].[element_name_reference]",
      "type": "string",
      "examples": ["button@minecraft", "button@minecraft.ui"],
      "pattern": "^[a-zA-Z0-9_]*@[a-zA-Z0-9_]+(\\.[a-zA-Z0-9_]+)?$"
    },
    {
      "title": "Element reference",
      "description": "A reference to an element: using the following syntax: [namespace_reference].[element_name_reference]",
      "type": "string",
      "examples": ["button@minecraft", "button@minecraft.ui"],
      "pattern": "[a-zA-Z0-9_]+(\\.[a-zA-Z0-9_]+)?$"
    },
    {
      "title": "Variable reference",
      "description": "A variable is a reference to a value that can be used in the UI.",
      "type": "string",
      "anyOf": [
        {
          "pattern": "^\\$[a-zA-Z0-9_]+$"
        },
        {
          "pattern": "^#[a-zA-Z0-9_]+$"
        },
        {
          "pattern": "^\\(.*\\)$"
        }
      ]
    }
  ]
}