SearchQuery.ts

import {parse, stringify} from 'query-string';

export class SearchQuery {
    private params: Object = {};

    /**
     * Class constructor
     *
     * @param {string} query Query string
     */
    constructor(query: string) {
        this.params = parse(query);
    }

    /**
     * Check if the specified parameter exists
     *
     * @param {string} name Name of the parameter
     * @return {boolean}
     */
    has(name: string): boolean {
        return name in this.params;
    }

    /**
     * Get value of the specified parmeter or fallback value if not found
     *
     * @param {string} name Name of the parameter
     * @param {any} fallback Fallback value
     * @return {any}
     */
    get(name: string, fallback: any = null): any {
        let {params} = this;

        // param exists
        if (this.has(name)) {
            return params[name];
        }

        return fallback;
    }

    /**
     * Get all specified parameters
     *
     * @return {Object}
     */
    getParams(): Object {
        return {...this.params};
    }

    /**
     * Convert current query parameters to a string
     *
     * @return {string}
     */
    toString(): string {
        return stringify(this.getParams());
    }
}