Javascript routing regex

Question

I need to build a router, that routes a REST request to a correct controller and action. Here some examples:

POST /users
GET /users/:uid
GET /users/search&q=lol
GET /users
GET /users/:uid/pictures
GET /users/:uid/pictures/:pid

It is important to have a single regular expression and as good as possible since routing is essential and done at every request.

we first have to replace : (untill end or untill next forward slash /) in the urls with a regex, that we can afterwards use to validate the url with the request url.

How can we replace these dynamic routings with regex? Like search for a string that starts with ":" and end with "/", end of string or "&".

This is what I tried:

var fixedUrl = new RegExp(url.replace(/\\\:[a-zA-Z0-9\_\-]+/g, '([a-zA-Z0-0\-\_]+)'));

For some reason it does not work. How could I implement a regex that replaces :id with a regex, or just ignores them when comparing to the real request url.

Thanks for help

Answer 1

I'd use :[^\s/]+ for matching parameters starting with colon (match :, then as many characters as possible except / and whitespace).

As replacement, I'm using ([\\w-]+) to match any alphanumeric character, - and _, in a capture group, given you're interested in using the matched parameters as well.

var route = "/users/:uid/pictures";
var routeMatcher = new RegExp(route.replace(/:[^\s/]+/g, '([\\w-]+)'));
var url = "/users/1024/pictures";

console.log(url.match(routeMatcher))