add subdomains section

Home.md

@@ -14,6 +14,7 @@ This wiki is the main source of documentation for **developers** working with (o
     * [[Reverse Lookups|Routing-reverse-lookups]]
     * [[Middleware|Routing-middleware]]
     * [[Handle HTTP errors|Routing-error-handlers]]
+    * [[Subdomains|Routing-subdomains]]
     * [[Wrap the Router|Routing-wrap-the-router]]
     * [[Dependency Injection|Routing-dependency-injection]]
 * [[Cookies]]

Routing-subdomains.md

@@ -0,0 +1,62 @@
+
+Iris has the simplest known form for subdomains registration to a single application. Of course you can always use nginx or caddy for managment in production.
+
+Subdomains are separated into two categories: **static** and **dynamic/wildcard**.
+
+* Static : when you know the subdomain, i.e : `analytics.mydomain.com`
+* Wildcard : when you don't know the subdomain but you know its form, i.e : `user_created.mydomain.com`, `otheruser.mydomain.com` like the  `username.github.io`
+
+We use the `Subdomain` and `WildcardSubdomain` methods of an `iris.Party` or `iris.Application` to register subdomains.
+
+The `Subdomain` method returns a new `Party` which is responsible to register routes to
+his specific "subdomain".
+
+The only difference from a regular `Party` is that if called from a child party then the subdomain will be prepended to the path instead of appended.
+So if `app.Subdomain("admin").Subdomain("panel")` then the result is: `"panel.admin."`.
+
+```go
+Subdomain(subdomain string, middleware ...Handler) Party
+```
+
+The `WildcardSubdomain` method returns a new `Party` which is responsible to register routes to
+a dynamic, wildcard(ed) subdomain. A dynamic subdomain is a subdomain which
+can handle any subdomain requests. Server will accept any subdomain
+(if not static subdomain found) and it will search and execute the handlers of this `Party`.
+
+```go
+WildcardSubdomain(middleware ...Handler) Party
+```
+
+To prove that subdomains works like any other regular `Party` you can also register a subdomain using the alternative method below:
+
+```go
+adminSubdomain:= app.Party("admin.")
+// or
+adminAnalayticsSubdomain := app.Party("admin.analytics.")
+// or for a dynamic one:
+app.Party("*.")
+```
+
+There is an `iris.Application` method which allows to register a global redirection rule for subdomains as well.
+
+The `SubdomainRedirect` sets (or adds if used more than one time) a router wrapper which
+redirects(StatusMovedPermanently) a (sub)domain to another subdomain or to the root domain as fast as possible,
+before the execution of the route's handler(s).
+
+It receives two arguments, they are the from and to/target locations,
+'from' can be a wildcard subdomain as well (app.WildcardSubdomain())
+'to' is not allowed to be a wildcard for obvious reasons,
+'from' can be the root domain(app) when the 'to' is not the root domain and visa-versa.
+
+```go
+SubdomainRedirect(from, to Party) Party
+```
+
+**Usage**:
+```go
+// [app := iris.New...]
+www := app.Subdomain("www")
+app.SubdomainRedirect(app, www)
+```
+
+The above will redirect all http(s)://mydomain.com/%anypath% to http(s)://www.mydomain.com/%anypath%.

_Sidebar.md

@@ -8,7 +8,8 @@
     * [[Path Parameter Types|Routing-path-parameter-types]]
     * [[Reverse Lookups|Routing-reverse-lookups]]
     * [[Middleware|Routing-middleware]]
-    * [[Custom error handlers|Routing-error-handlers]]
+    * [[Handle HTTP errors|Routing-error-handlers]]
+    * [[Subdomains|Routing-subdomains]]
     * [[Wrap the Router|Routing-wrap-the-router]]
     * [[Dependency Injection|Routing-dependency-injection]]
 * [[Cookies]]