Commas in Compojure routes

clojure, compojure, ring

Solution

Compojure uses `clout` for routing. From `clout`'s `README`:

Clout supports both keywords and wildcards. Keywords (like `:title`) will match any character but the following: `/ . , ; ?`.

By default, `clout` treats commas as path segment separators. You can work around that by passing a custom regex to the route. The following would make `:tag-names` match any character except `/`:

(GET ["/tags/multiple/:tag-names" :tag-names #"[^/]+"] [tag-names] multiple-tags)

Problem

I'm trying to create a route that has a parameter which contains commas in compojure ``` (GET "/tags/multiple/:tag-names" [tag-names] multiple-tags) ``` but for some reason, whenever I include a comma in the `:tag-names` field, it 404s. It works fine when there are no commas. Does anyone know what causes this and how I can work around it?

Original source