Class HttpParams

packages/common/http/src/params.ts:165–357

 * @publicApi
 */
export class HttpParams {
  private map: Map<string, string[]> | null;
  private encoder: HttpParameterCodec;
  private updates: Update[] | null = null;
  private cloneFrom: HttpParams | null = null;

  constructor(options: HttpParamsOptions = {} as HttpParamsOptions) {
    this.encoder = options.encoder || new HttpUrlEncodingCodec();
    if (options.fromString) {
      if (options.fromObject) {
        throw new RuntimeError(
          RuntimeErrorCode.CANNOT_SPECIFY_BOTH_FROM_STRING_AND_FROM_OBJECT,
          ngDevMode && 'Cannot specify both fromString and fromObject.',
        );
      }
      this.map = paramParser(options.fromString, this.encoder);
    } else if (!!options.fromObject) {
      this.map = new Map<string, string[]>();
      Object.keys(options.fromObject).forEach((key) => {
        const value = (options.fromObject as any)[key];
        // convert the values to strings
        const values = Array.isArray(value) ? value.map(valueToString) : [valueToString(value)];
        this.map!.set(key, values);
      });
    } else {
      this.map = null;
    }
  }

  /**
   * Reports whether the body includes one or more values for a given parameter.
   * @param param The parameter name.
   * @returns True if the parameter has one or more values,
   * false if it has no value or is not present.
   */
  has(param: string): boolean {
    this.init();
    return this.map!.has(param);
  }

  /**
   * Retrieves the first value for a parameter.
   * @param param The parameter name.
   * @returns The first value of the given parameter,
   * or `null` if the parameter is not present.
   */
  get(param: string): string | null {
    this.init();
    const res = this.map!.get(param);
    return !!res ? res[0] : null;
  }

  /**
   * Retrieves all values for a  parameter.
   * @param param The parameter name.
   * @returns All values in a string array,
   * or `null` if the parameter not present.
   */