pdc

Persistent Data Container (PDC) Utility Expressions for Skript

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Overview

This document describes a set of Skript expressions and helpers for interacting with Bukkit's PersistentDataContainer (PDC).

It supports:

• Native PersistentDataType (PDT) values
• Arbitrary object storage via Java serialization into BYTE_ARRAY

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Requirements

• Paper server
• Skript
• skript-reflect

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Key Features

1. Unified key … in pdc Expression

• Read, write, and delete PDC entries using a single expression
• Automatically resolves:
  • PersistentDataHolder → PersistentDataContainer

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2. Native and Arbitrary Object Storage

• When a PersistentDataType is provided: → Values are stored natively using that PDT
• When omitted: → Values are serialized and stored as PersistentDataType.BYTE_ARRAY

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3. Built-in NamespacedKey Handling

There is no standalone NamespacedKey expression.

Instead, namespaced keys are handled directly by the main expression using string input.

Key strings must be in the form:

namespace:key

Example:

"minecraft:foo"
"myplugin:data"

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4. Safety and Validation

• Runtime validation ensures correct types for:

  • Key string
  • Container / holder
  • PersistentDataType (if provided)

• Invalid expressions fail silently to avoid hard Skript errors

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Serialization Notes

• Arbitrary objects are serialized using BukkitObjectOutputStream
• Data is stored directly as byte[] via PersistentDataType.BYTE_ARRAY
• Objects must implement java.io.Serializable

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Syntax Summary

Core Expression

expression [devdinc] [namespaced]( |-)key %string% [with]in %pdcholder/pdc% [for %-pdt%]

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Reading

set {_value} to key "plugin:test" within player's pdc
set {_value} to key "plugin:test" in player's pdc for pdt string

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Writing

set key "plugin:test" within player's pdc to {_object}
set key "plugin:test" in player's pdc for pdt integer to 5

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Deleting

delete key "plugin:test" within player's pdc

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Behavior Notes

• If no PersistentDataType is specified, BYTE_ARRAY storage is used
• Setting a key to null removes the entry
• Deleting a key removes it regardless of storage type

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Caveats

• Deserialization failures will propagate runtime errors
• Class definition changes may break previously serialized data
• Stored objects must remain compatible with Java serialization

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