From e2443833eb6dfe0e3b45685e058d52ed4ac4d6fe Mon Sep 17 00:00:00 2001
From: Oliver-Akins <Oliver.akins1999@gmail.com>
Date: Sun, 7 Jan 2024 00:11:42 -0700
Subject: [PATCH] Add utility data field from the dnd5e system

---
 module/models/fields/MappingField.mjs | 132 ++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)
 create mode 100644 module/models/fields/MappingField.mjs

diff --git a/module/models/fields/MappingField.mjs b/module/models/fields/MappingField.mjs
new file mode 100644
index 0000000..9d62f66
--- /dev/null
+++ b/module/models/fields/MappingField.mjs
@@ -0,0 +1,132 @@
+/*
+This class was pulled from the official D&D 5e Foundry System
+
+Original Authors:
+	Jeff Hitchcock (https://github.com/arbron)
+	Andrew (https://github.com/aaclayton)
+
+Accessed on: 2024/01/06
+
+Source Code: https://github.com/foundryvtt/dnd5e/blob/677c6ae127aa885bd4cb9a83f95180a655a8623b/module/data/fields.mjs#L264
+*/
+
+
+/**
+ * A subclass of ObjectField that represents a mapping of keys to the provided DataField type.
+ *
+ * @param {DataField} model                    The class of DataField which should be embedded in this field.
+ * @param {MappingFieldOptions} [options={}]   Options which configure the behavior of the field.
+ * @property {string[]} [initialKeys]          Keys that will be created if no data is provided.
+ * @property {MappingFieldInitialValueBuilder} [initialValue]  Function to calculate the initial value for a key.
+ * @property {boolean} [initialKeysOnly=false]  Should the keys in the initialized data be limited to the keys provided
+ *                                              by `options.initialKeys`?
+ */
+export class MappingField extends foundry.data.fields.ObjectField {
+	constructor(model, options) {
+		if ( !(model instanceof foundry.data.fields.DataField) ) {
+			throw new Error("MappingField must have a DataField as its contained element");
+		}
+		super(options);
+
+		/**
+		 * The embedded DataField definition which is contained in this field.
+		 * @type {DataField}
+		 */
+		this.model = model;
+	}
+
+	/* -------------------------------------------- */
+
+	/** @inheritdoc */
+	static get _defaults() {
+		return foundry.utils.mergeObject(super._defaults, {
+			initialKeys: null,
+			initialValue: null,
+			initialKeysOnly: false
+		});
+	}
+
+	/* -------------------------------------------- */
+
+	/** @inheritdoc */
+	_cleanType(value, options) {
+		Object.entries(value).forEach(([k, v]) => value[k] = this.model.clean(v, options));
+		return value;
+	}
+
+	/* -------------------------------------------- */
+
+	/** @inheritdoc */
+	getInitialValue(data) {
+		let keys = this.initialKeys;
+		const initial = super.getInitialValue(data);
+		if ( !keys || !foundry.utils.isEmpty(initial) ) return initial;
+		if ( !(keys instanceof Array) ) keys = Object.keys(keys);
+		for ( const key of keys ) initial[key] = this._getInitialValueForKey(key);
+		return initial;
+	}
+
+	/* -------------------------------------------- */
+
+	/**
+	 * Get the initial value for the provided key.
+	 * @param {string} key       Key within the object being built.
+	 * @param {object} [object]  Any existing mapping data.
+	 * @returns {*}              Initial value based on provided field type.
+	 */
+	_getInitialValueForKey(key, object) {
+		const initial = this.model.getInitialValue();
+		return this.initialValue?.(key, initial, object) ?? initial;
+	}
+
+	/* -------------------------------------------- */
+
+	/** @override */
+	_validateType(value, options={}) {
+		if ( foundry.utils.getType(value) !== "Object" ) throw new Error("must be an Object");
+		const errors = this._validateValues(value, options);
+		if ( !foundry.utils.isEmpty(errors) ) throw new foundry.data.fields.ModelValidationError(errors);
+	}
+
+	/* -------------------------------------------- */
+
+	/**
+	 * Validate each value of the object.
+	 * @param {object} value     The object to validate.
+	 * @param {object} options   Validation options.
+	 * @returns {Object<Error>}  An object of value-specific errors by key.
+	 */
+	_validateValues(value, options) {
+		const errors = {};
+		for ( const [k, v] of Object.entries(value) ) {
+			const error = this.model.validate(v, options);
+			if ( error ) errors[k] = error;
+		}
+		return errors;
+	}
+
+	/* -------------------------------------------- */
+
+	/** @override */
+	initialize(value, model, options={}) {
+		if ( !value ) return value;
+		const obj = {};
+		const initialKeys = (this.initialKeys instanceof Array) ? this.initialKeys : Object.keys(this.initialKeys ?? {});
+		const keys = this.initialKeysOnly ? initialKeys : Object.keys(value);
+		for ( const key of keys ) {
+			const data = value[key] ?? this._getInitialValueForKey(key, value);
+			obj[key] = this.model.initialize(data, model, options);
+		}
+		return obj;
+	}
+
+	/* -------------------------------------------- */
+
+	/** @inheritdoc */
+	_getField(path) {
+		if ( path.length === 0 ) return this;
+		else if ( path.length === 1 ) return this.model;
+		path.shift();
+		return this.model._getField(path);
+	}
+}
\ No newline at end of file