From 3cb32c5ec9e2c5331d3a9c19678defe226ef7bba Mon Sep 17 00:00:00 2001
From: "Alexander \"Arav\" Andreev" <me@arav.su>
Date: Fri, 11 Aug 2023 18:42:28 +0400
Subject: [PATCH] Sub-path implemented, now you can make a sub for a section
 using Router's Sub(root) method and then write only what this section
 contains. Like s := Sub("/api/v1") and then s.Handler("/").

---
 httpr.go | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/httpr.go b/httpr.go
index 0c12dc5..5dcbef0 100644
--- a/httpr.go
+++ b/httpr.go
@@ -212,6 +212,34 @@ func (rr *Router) ServeStatic(path string, root http.FileSystem) error {
 	})
 }
 
+// subPath contains a root path that is being attached in front of a pattern
+// passed by a Handler() func.
+type subPath struct {
+	r    *Router
+	root string
+}
+
+// Sub returns a sub-path with a root path, after that you can shorten patterns.
+//
+// E.g. instead of writing each time "/api/something/other" create a
+// sub-router with a root path "/api/something" and then pass just "/other" in
+// a Handler() func of subPath struct.
+func (rr *Router) Sub(root string) *subPath {
+	if root[len(root)-1] == '/' {
+		root = root[:len(root)-1]
+	}
+
+	return &subPath{
+		r:    rr,
+		root: root,
+	}
+}
+
+// Handler attaches root path to a given pattern and pass it to a router.
+func (sp *subPath) Handler(method, pattern string, handler http.HandlerFunc) error {
+	return sp.r.Handler(method, sp.root+pattern, handler)
+}
+
 // Param returns a URL parameter (that is set like `/a/b/:key/d`) with a key
 // or an empty string if no such parameter found.
 func Param(r *http.Request, key string) string {