vcard4/src/parameters/BaseParameter.js

An RFC 6350 compliant JavaScript library for generating and parsing version 4.0 vCards. Can also generate RFC 6351 compliant XML vCards and RFC 7095 compliant jCards. TypeScript type declarations are provided.

export class BaseParameter {
  #abstractPropertiesAndMethods = [
    "param",
    "value",
    "valueXML",
    "valueJSON",
    "identifier",
  ];

  checkAbstractPropertiesAndMethods() {
    if (
      !this.#abstractPropertiesAndMethods.every(
        (abstractPropertyOrMethod) =>
          Object.prototype.hasOwnProperty.call(
            this,
            abstractPropertyOrMethod
          ) ||
          Object.prototype.hasOwnProperty.call(
            Object.getPrototypeOf(this),
            abstractPropertyOrMethod
          ) ||
          Object.prototype.hasOwnProperty.call(
            this.constructor,
            abstractPropertyOrMethod
          )
      )
    )
      throw new Error(
        "All abstract properties and methods in abstract base class must be defined in child class"
      );
  }

  repr() {
    return `${this.constructor.param || this.param}=${this.value}`;
  }

  reprXML() {
    const tag =
      this.constructor.param?.toLowerCase() || this.param?.toLowerCase();

    const knownTagRegExp =
      /^(?:altid|base|calscale|cc|geo|index|label|language|level|mediatype|pid|pref|sort-as|type|tz|value|x-[A-Za-z0-9]+)$/;

    if (!knownTagRegExp.test(tag))
      return `<unknown>${this.valueXML
        .replace(/<[a-z\-]+?>/g, "<text>")
        .replace(/<\/[a-z\-]+?>/g, "</text>")}</unknown>`;
    else if (tag === "value") return "";

    return `<${tag}>${this.valueXML}</${tag}>`;
  }

  reprJSON() {
    const key =
      this.constructor.param?.toLowerCase() || this.param?.toLowerCase();

    if (key === "value") return {};

    let value = this.valueJSON;
    value.shift();
    value = value.map((val) => val.toString());

    if (value.length === 1) value = value.pop();

    return { [key]: value };
  }

  constructor() {
    if (this.constructor === BaseParameter)
      throw new Error("Cannot create instance of base class");
  }
}

Object.freeze(BaseParameter);