# Advanced Path Matching

By default, path matching in Zuplo uses the OpenAPI slug format, for example
`/pizza/{size}` where **size** would be a URL parameter, with the value passed
into the runtime as `request.params.size` property.

However, you can opt to use a more advanced path matching approach based on the
web standard
[URLPattern](https://developer.mozilla.org/en-US/docs/Web/API/URLPattern).

In order to use URLPattern matching you must set your route's
`x-zuplo-path.pathMode` to `url-pattern`.

The URLPattern matching mode can be set in the UI as shown below:

![Route ](../../public/media/advanced-path-matching/image.png)

Alternatively, you can set it in your OpenAPI file as follows:

```json {4-6} title="config/routes.oas.json"
{
  "paths": {
    "/files/:path*": {
      "x-zuplo-path": {
        "pathMode": "url-pattern"
      }
    }
  }
}
```

The most basic path is `/` which will simple match the root path. You can add
other static paths like `/foo` and `/foo/bar`

:::tip

Use [URLPattern.com](https://urlpattern.com) to test your URL Patterns in the
browser.

:::

## Trailing Slashes

In URLPattern, trailing slashes aren't accepted unless explicitly specified. For
example:

- `/cars/:manufacturer`

Would match `/cars/ford` but not `/cars/ford/`. If you want to support this you
must add a little regex to the end of your path, for example -
`/cars/:manufacturer{/}?`

Will match both example routes given above.

## Dynamic Paths

URLPattern supports dynamic matching including a feature that will parameterize
parts of the URL. For example:

Path: `/products/:productId/sizes/:size` will match the following paths

`/products/pizza/size/small` and set the `params` object on `request` to:

```json
{
  "productId": "pizza",
  "size": "small"
}
```

:::tip

Query-strings (or search parameters) won't affect path matching.

:::

## Regular Expressions and Wildcards

You can also use regular expressions in your paths. They must be contained in
`()`.

**Examples**

Path `/(.*)` will match anything.

:::note

This is a true wildcard route and can be used for custom 404s by making this the
last route in your OpenAPI file (and matching all methods).

:::

Path `/(a?b)` will match either `/ab` or `/b`.

Path `/main/(a|b)` will match `/main/a` or `/main/b`.

Path `/icon-(\d++).png` will match `/icon-1234.png` or any other series of
digits for 1234.

## Named groups

You can also name your regexp groups so that they appear as named parameters.

`name:(.*)` - will match a wildcard and call the parameter.

For example, the path `products/:productId/icons/icon-:imageIndex(\d+).png` will
match `/products/pizza/icons/icon-2.png` and produce a `request.params` object
as follows:

```json
{
  "productId": "pizza",
  "imageIndex": "2"
}
```

You can write a [URL Rewrite](../handlers/url-rewrite.mdx) that takes an
incoming wildcard and appends it to the backend request, for example Path:
`/foo/bar:path(/.*)` Incoming URL: `/foo/bar/apple/banana` URL Rewrite Pattern:
`https://example.com/x${params.path}` Outgoing URL:
`https://example.com/x/apple/banana`

## Not supported

Note that not all regex features are available, us of the following will either
be ignored or result in an error, including

- `(?:...)` - named matches
- `^` or `$` - start or end of string
- `[abc]` - character classes