URLPattern: hasRegExpGroups property

{{APIRef("URL Pattern API")}} {{AvailableInWorkers}}

The hasRegExpGroups read-only property of the {{domxref("URLPattern")}} interface is a boolean indicating whether or not any of the URLPattern components contain regular expression capturing groups.

You can use the hasRegExpGroups property to check if a URLPattern object is usable with certain web platform APIs which do not allow regular expression capturing groups. For example:

• The match directive in the {{HTTPHeader("Use-As-Dictionary")}} HTTP header prohibits regular expression capturing groups, as well as
• the urlPattern condition when adding static routes using the {{domxref("InstallEvent.addRoutes()")}} method.

Value

A boolean.

Examples

Using hasRegExpGroups

In the following example, a {{domxref("URLPattern")}} object is used with a group delimiter containing named capturing groups called "id" and "title". The hasRegExpGroups property returns true in this case.

const pattern = new URLPattern({ pathname: "/blog/:id(\\d+){-:title}?" });
console.log(pattern.hasRegExpGroups); // true
const result = pattern.exec({ pathname: "/blog/123-some-article" });
console.log(result.pathname.groups); // {id: '123', title: 'some-article'}

It also works with anonymous capturing groups.

const pattern = new URLPattern({ pathname: "/blog/(\\d+)" });
console.log(pattern.hasRegExpGroups); // true
const result = pattern.exec({ pathname: "/blog/123" });
console.log(result.pathname.groups); // {0: '123'}

For other non-capturing groups, for example when using wildcard tokes (*), hasRegExpGroups will return false.

const pattern = new URLPattern({ pathname: "/blog/*" });
console.log(pattern.hasRegExpGroups); // false
const result = pattern.exec({ pathname: "/blog/123" });
console.log(result.pathname.groups); // {0: '123'}

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}