src/Attribute.js

import * as asn1js from "asn1js";
import { getParametersValue, clearProps } from "pvutils";
//**************************************************************************************
/**
 * Class from RFC2986
 */
export default class Attribute {
	//**********************************************************************************
	/**
	 * Constructor for Attribute class
	 * @param {Object} [parameters={}]
	 * @property {Object} [schema] asn1js parsed value
	 */
	constructor(parameters = {})
	{
		//region Internal properties of the object
		/**
		 * @type {string}
		 * @description type
		 */
		this.type = getParametersValue(parameters, "type", Attribute.defaultValues("type"));
		/**
		 * @type {Array}
		 * @description values
		 */
		this.values = getParametersValue(parameters, "values", Attribute.defaultValues("values"));
		//endregion
		
		//region If input argument array contains "schema" for this object
		if("schema" in parameters)
			this.fromSchema(parameters.schema);
		//endregion
	}
	//**********************************************************************************
	/**
	 * Return default values for all class members
	 * @param {string} memberName String name for a class member
	 */
	static defaultValues(memberName)
	{
		switch(memberName)
		{
			case "type":
				return "";
			case "values":
				return [];
			default:
				throw new Error(`Invalid member name for Attribute class: ${memberName}`);
		}
	}
	//**********************************************************************************
	/**
	 * Compare values with default values for all class members
	 * @param {string} memberName String name for a class member
	 * @param {*} memberValue Value to compare with default value
	 */
	static compareWithDefault(memberName, memberValue)
	{
		switch(memberName)
		{
			case "type":
				return (memberValue === "");
			case "values":
				return (memberValue.length === 0);
			default:
				throw new Error(`Invalid member name for Attribute class: ${memberName}`);
		}
	}
	//**********************************************************************************
	/**
	 * Return value of asn1js schema for current class
	 * @param {Object} parameters Input parameters for the schema
	 * @returns {Object} asn1js schema object
	 */
	static schema(parameters = {})
	{
		// Attribute { ATTRIBUTE:IOSet } ::= SEQUENCE {
		//    type   ATTRIBUTE.&id({IOSet}),
		//    values SET SIZE(1..MAX) OF ATTRIBUTE.&Type({IOSet}{@type})
		//}
		
		/**
		 * @type {Object}
		 * @property {string} [blockName]
		 * @property {string} [type]
		 * @property {string} [setName]
		 * @property {string} [values]
		 */
		const names = getParametersValue(parameters, "names", {});
		
		return (new asn1js.Sequence({
			name: (names.blockName || ""),
			value: [
				new asn1js.ObjectIdentifier({ name: (names.type || "") }),
				new asn1js.Set({
					name: (names.setName || ""),
					value: [
						new asn1js.Repeated({
							name: (names.values || ""),
							value: new asn1js.Any()
						})
					]
				})
			]
		}));
	}
	//**********************************************************************************
	/**
	 * Convert parsed asn1js object into current class
	 * @param {!Object} schema
	 */
	fromSchema(schema)
	{
		//region Clear input data first
		clearProps(schema, [
			"type",
			"values"
		]);
		//endregion
		
		//region Check the schema is valid
		const asn1 = asn1js.compareSchema(schema,
			schema,
			Attribute.schema({
				names: {
					type: "type",
					values: "values"
				}
			})
		);
		
		if(asn1.verified === false)
			throw new Error("Object's schema was not verified against input data for Attribute");
		//endregion
		
		//region Get internal properties from parsed schema
		this.type = asn1.result.type.valueBlock.toString();
		this.values = asn1.result.values;
		//endregion
	}
	//**********************************************************************************
	/**
	 * Convert current object to asn1js object and set correct values
	 * @returns {Object} asn1js object
	 */
	toSchema()
	{
		//region Construct and return new ASN.1 schema for this object
		return (new asn1js.Sequence({
			value: [
				new asn1js.ObjectIdentifier({ value: this.type }),
				new asn1js.Set({
					value: this.values
				})
			]
		}));
		//endregion
	}
	//**********************************************************************************
	/**
	 * Convertion for the class to JSON object
	 * @returns {Object}
	 */
	toJSON()
	{
		return {
			type: this.type,
			values: Array.from(this.values, element => element.toJSON())
		};
	}
	//**********************************************************************************
}
//**************************************************************************************