vcard4/src/properties/BaseProperty.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 BaseProperty {
  #abstractPropertiesAndMethods = [
    "prop",
    "cardinality",
    "acceptableParamTypes",
    "acceptableValTypes",
    "params",
    "paramsXML",
    "paramsJSON",
    "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 base class must be defined in child class"
      );
  }

  repr() {
    const contentLine =
      this.params === ""
        ? `${this.constructor.prop || this.prop}:${this.value}`
        : `${this.constructor.prop || this.prop};${this.params}:${this.value}`;

    const LINEBREAK = "\r\n" + " ";
    const MAXWIDTH = 75;

    if (contentLine.length <= MAXWIDTH) return contentLine;

    let foldedContentLine = "";

    for (let index = 0; index < contentLine.length; index++) {
      if (index > 0 && index % MAXWIDTH === 0)
        foldedContentLine += LINEBREAK + contentLine[index];
      else foldedContentLine += contentLine[index];
    }
    return foldedContentLine;
  }

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

    if (tag === "xml") return this.valueXML;

    return this.paramsXML === ""
      ? `<${tag}>${this.valueXML}</${tag}>`
      : `<${tag}><parameters>${this.paramsXML}</parameters>${this.valueXML}</${tag}>`;
  }

  reprJSON() {
    return [
      this.constructor.prop?.toLowerCase() || this.prop?.toLowerCase(),
      this.paramsJSON,
      ...this.valueJSON,
    ];
  }

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

Object.freeze(BaseProperty);