Reset WordPress add term form after save.

add-term-reset-form.js

/**
 * Add ajaxprefilter to reset the form
 */
function initAjaxPreFilter() {
    // Add callback
	$( document ).on( 'term:added', function() {
		// Do reset form related stuff here
	} );

    // Register ajaxprefilter
    $.ajaxPrefilter( function( options, originalOptions, jqXHR ) {

        // Convert query string to object
        if ( 'string' === typeof( originalOptions.data ) ) {
            originalOptions.data = parseQuery( originalOptions.data );
        }

        // Modify options, control originalOptions, store jqXHR, etc
        if ( null === originalOptions.data || 'undefined' === typeof ( originalOptions.data ) || 'undefined' === typeof ( originalOptions.data.action ) ) {
            return true;
        }
        if ( 'add-tag' === originalOptions.data.action ) {
            var orignalSuccess = originalOptions.success;
            options.success = function( response ) {
                orignalSuccess( response );

                // Reset image field
                $( document ).trigger( 'term:added', response );
            };
        }
    });
}

/**
 * Convert query string to object
 * @param qstr
 * @returns {{}}
 */
function parseQuery( qstr ) {
	var query = {};
	var a = qstr.substr( 0 ).split( '&' );
	for ( var i = 0; i < a.length; i++ ) {
		var b = a[i].split( '=' );
		query[decodeURIComponent( b[0] )] = decodeURIComponent( b[1] ||
			'' );
	}
	return query;
}