Golink

The Golink crate is an engine for resolving URLs for link shortening services. You provide a link to expand and a function for mapping short URLs to long URLs, and this crate will:

• Normalize your input to ignore case and hyphenation: http://go/My-Service and http://go/myservice are treated as the same input into your mapping function

• Append secondary paths to your resolved URL: if your mapping function returns http://example.com for the given shortlink foo, then a request to http://go/foo/bar/baz will resolve to http://example.com/foo/bar/baz

• Apply templating, when applicable: Using a simple templating language, your long URLs can powerfully place remaining path segments in your URL ad-hoc and provide a fallback value when there are no remaining path segments. For example, if your mapping function returns for the given shortlink prs the following URL:

  text https://github.com/pulls?q=is:open+is:pr+review-requested:{{ if path }}{ path }{{ else }}@me{{ endif }}+archived:false

  then a request to http://go/prs returns the URL to all Github PRs to which you are assigned:

  text https://github.com/pulls?q=is:open+is:pr+review-requested:@me+archived:false

  and a request to http://go/prs/jameslittle230 returns the URL to all Github PRs to which I (@jameslittle230) am assigned:

  text https://github.com/pulls?q=is:open+is:pr+review-requested:jameslittle230+archived:false

This resolver performs all the functionality described in Tailscale's Golink project

This crate doesn't provide a web service or an interface for creating shortened links; it only provides an algorithm for resolving short URLs to long URLs.

Usage

The Golink crate doesn't care how you store or retrieve long URLs given a short URL; you can store them in memory, in a database, or on disk, as long as they are retrievable from within a closure you pass into the resolve() function:

```rust fn lookup(input: &str) -> Option { if input == "foo" { return Some("http://example.com".to_string()); } None }

let resolved = golink::resolve("http://go/foo", &lookup)

match computed { Ok(GolinkResolution::RedirectRequest(url)) => { // Redirect to url }

Ok(GolinkResolution::MetadataRequest(key)) => { // key is the original shortlink. // Return JSON that displays metadata/analytics about key }

Err(e) => { // Return a 400 error to the user, with a message based on e } } ```