@gravityforms/utils/src/data/update-query-var.js

JavaScript utilities for Gravity Forms development.

/**
 * @module updateQueryVar
 * @description Modify a URL string's query args, by either adding a new one, updating an existing one,
 * or removing an existing one.
 *
 * @since 1.0.0
 *
 * @param {string}      key   The URL param key.
 * @param {string|null} value The value for the key. Set to null to remove query arg.
 * @param {string}      url   An URL string to manipulate. Defaults to current.
 *
 * @return {string} Returns the updated URL.
 *
 * @example
 * import { updateQueryVar } from "@gravityforms/utils";
 *
 * function Example() {
 *   const url    = 'http://domain.com/?query1=val1';
 * 	 const newUrl = updateQueryVar( 'query2', 'val2', url );
 * }
 *
 */
export default function updateQueryVar( key, value, url = window.location.href ) {
	const separator = '?';

	const hashSplit = url.split( '#' );
	const hash = hashSplit[ 1 ] ? `#${ hashSplit[ 1 ] }` : '';
	const querySplit = hashSplit[ 0 ].split( '?' );
	const host = querySplit[ 0 ];
	const query = querySplit[ 1 ];
	const params = query !== undefined ? query.split( '&' ) : [];
	let updated = false;

	params.forEach( ( item, index ) => {
		if ( item.startsWith( `${ key }=` ) ) {
			updated = true;
			if ( ! value ) {
				// value is null, remove query arg
				params.splice( index, 1 );
			} else {
				// update query arg
				params[ index ] = `${ key }=${ value }`;
			}
		}
	} );

	if ( ! updated && value ) {
		// this is a new arg to add
		params[ params.length ] = `${ key }=${ value }`;
	}

	return `${ host }${ separator }${ params.join( '&' ) }${ hash }`;
}