Deep and nested query parameters for Angular, for use with things like Strapi

ngDeepQuery.js

class DeepQuery {
  constructor(public query: any) {

  }

  private isObj(obj: any): boolean {
    return (
      typeof obj === 'object' &&
      obj !== null
    )
  }

  private toQPK(crumbs: string[]): string {
    if (crumbs.length == 0) {
      throw new Error(`Parameter without key`)
    }
    return crumbs[0] + crumbs.slice(1).map(s => `[${s}]`).join("");
  }

  private parse(obj: any, crumbs: string[] = [], memo: {[key: string]: any} = {}) {
    if (!this.isObj(obj)) {
      memo[this.toQPK(crumbs)] = obj;
    } else if (Array.isArray(obj)) {
      for (let i = 0; i < obj.length; i++) {
        crumbs.push(i.toString());
        this.parse(obj[i], crumbs, memo);
        crumbs.pop();
      }
    } else {
      for (let key in obj) {
        if (obj.hasOwnProperty(key)) {
          crumbs.push(key);
          this.parse(obj[key], crumbs, memo)
          crumbs.pop();
        }
      }
    }
    return memo;
  }

  public encode() {
    return this.parse(this.query);
  }
}