Host Parsing

[PorterHoskins]

Sometimes parsing the host value is needed when working with multiple server environments or distributed enterprise systems. The urls that I need to parse are as follows:

https://<server>.company.io/
https://<server>.stage.company.io/
https://<server>.int.company.io/

Parsing the server value in the host is needed to understand which server I should be pointing my url requests at. Currently I don't believe there is a way to run a parser on the host value of a URLRequestData. The Host parser requires a static string for the entire host.

Is there a way I am not thinking about to run a parser on the host without getting the .host off the URLRequestData and running it through its own parser?

[abear247]

I just ran into the same issue today, I found a workaround that works for at least my case so I thought I would share. We needed to set different server codes depending on the host. As you are aware, we can't parse a host similar to how we would parse a Path for example. So you kind of want to invert the setup to parse this.

I have an enum

enum ServerCode: String {
    case us = "US"
    case ca = "CA"
}

I then added an extension to this

extension ServerCode {
    static let parser = OneOf {
        Parse(.case(Self.ca)) {
            Host("app-ca.example.com")
        }
        Parse(.case(Self.us)) {
            OneOf {
                Host("app.example.com")
                Host("staging.example.com")
            }
        }
    }
}

This is now usable like so

struct ExampleParser: Parser {
    var body: some Parser<URLRequestData, AppRoute> {
       Route(.case(AppRoute.example(serverCode:))) {
            ServerCode.parser
            // everything else you want to parse
       }
    }
}

I know this discussion was posted a long time ago, but hope this helps someone!