[REST] Simplify @path handling

Ultimately, we want to make @rootPathAttribute the default for interface (it's already the default behavior for methods), and remove the @rootpath attribute, because it's redundant with @path, and they currently don't overlap, @rootpath being dedicated to interfaces, and @path to method.

This commit:
- Document future deprecation of @rootpath and redefine @rootpath and @rootPathFromName in terms of @path;
- Documents @path better;
- Communicate the settings to the sub-interface;

examples/rest/source/app.d

@@ -154,6 +154,7 @@ interface Example3API
 	int getMyID(int id);
 }
 
+@path("/")
 interface Example3APINested
 {
 	/* In this example it will be available under "GET /nested_module/number"

source/vibe/web/common.d

@@ -260,7 +260,7 @@ unittest
 
 
 /**
-    UDA to defeine the ContentType for methods returning an InputStream or ubyte[]
+    UDA to define the ContentType for methods returning an InputStream or ubyte[]
 */
 ContentTypeAttribute contentType(string data) 
 {
@@ -291,11 +291,20 @@ MethodAttribute method(HTTPMethod data)
 }
 
 /**
-	User Defined Attribute interface to force specific URL path n REST interface
-	for function in question. Path attribute is relative though, not absolute.
+	UDA to force a specific URL path for REST interfaces.
+
+	This attribute can be applied either to an interface itself, in which
+	case it defines the root path for all methods within it,
+	or on any function, in which case it defines the relative path
+	of this method.
+	Path are always relative, even path on interfaces, as you can
+	see in the example below.
+
+	See_Also: $(D rootPathFromName) for automatic name generation.
 
 	Example:
 	---
+	@path("/foo")
 	interface IAPI
 	{
 		@path("info2") getInfo();
@@ -305,8 +314,10 @@ MethodAttribute method(HTTPMethod data)
 	
 	shared static this()
 	{
+		// Tie IAPI.getInfo to "GET /root/foo/info2"
 		registerRestInterface!IAPI(new URLRouter(), new API(), "/root/");
-		// now IAPI.getInfo is tied to "GET /root/info2"
+		// Or just to "GET /foo/info2"
+		registerRestInterface!IAPI(new URLRouter(), new API());
 	}
 	---	
 */
@@ -319,51 +330,23 @@ PathAttribute path(string data)
 
 
 /**
-	UDA to define root URL prefix for annotated REST interface.
-	Empty path means deducing prefix from interface type name (see also rootPathFromName)
+	Will be deprecated in the next release.
+	Use @$(D path) instead.
  */
-RootPathAttribute rootPath(string path)
+PathAttribute rootPath(string path)
 {
 	if (!__ctfe)
 		assert(false, onlyAsUda!__FUNCTION__);
-	return RootPathAttribute(path);
-}
-///
-unittest
-{
-	import vibe.http.router;
-	import vibe.web.rest;
-
-	@rootPath("/oops")
-	interface IAPI
-	{
-		int getFoo();
-	}
-
-	class API : IAPI
-	{
-		int getFoo()
-		{
-			return 42;
-		}
-	}
-
-	auto router = new URLRouter();
-	registerRestInterface(router, new API());
-	auto routes= router.getAllRoutes();
-
-	assert(routes[0].pattern == "/oops/foo" && routes[0].method == HTTPMethod.GET);
+	return PathAttribute(path);
 }
 
 
-/**
-	Convenience alias
- */
-@property RootPathAttribute rootPathFromName()
+/// Convenience alias to generate a name from the interface's name.
+@property PathAttribute rootPathFromName()
 {
 	if (!__ctfe)
 		assert(false, onlyAsUda!__FUNCTION__);
-	return RootPathAttribute("");
+	return PathAttribute("");
 }
 ///
 unittest

source/vibe/web/rest.d

@@ -79,7 +79,7 @@ void registerRestInterface(TImpl)(URLRouter router, TImpl instance, RestInterfac
 
 	string url_prefix = settings.baseURL.path.toString();
 
-	enum uda = findFirstUDA!(RootPathAttribute, I);
+	enum uda = findFirstUDA!(PathAttribute, I);
 	static if (uda.found) {
 		static if (uda.value.data == "") {
 			auto path = "/" ~ adjustMethodStyle(I.stringof, settings.methodStyle);
@@ -129,10 +129,12 @@ void registerRestInterface(TImpl)(URLRouter router, TImpl instance, RestInterfac
 					ParameterTypeTuple!overload.length == 0,
 					"Interfaces may only be returned from parameter-less functions!"
 				);
+				auto subSettings = settings.dup;
+				subSettings.baseURL = URL(concatURL(url_prefix, url, true));
 				registerRestInterface!RT(
 					router,
 					__traits(getMember, instance, method)(),
-					concatURL(url_prefix, url, true)
+					subSettings
 				);
 			} else {
 				// normal handler
@@ -180,6 +182,7 @@ void registerRestInterface(TImpl)(URLRouter router, TImpl instance, string url_p
 */
 unittest
 {
+	@path("/")
 	interface IMyAPI
 	{
 		// GET /api/greeting
@@ -287,7 +290,7 @@ class RestInterfaceClient(I) : I
 		}
 
 		URL url = settings.baseURL;
-		enum uda = findFirstUDA!(RootPathAttribute, I);
+		enum uda = findFirstUDA!(PathAttribute, I);
 		static if (uda.found) {
 			static if (uda.value.data == "") {
 				url.path = Path(concatURL(url.path.toString(), adjustMethodStyle(I.stringof, settings.methodStyle), true));
@@ -474,6 +477,7 @@ class RestInterfaceClient(I) : I
 ///
 unittest
 {
+	@path("/")
 	interface IMyApi
 	{
 		// GET /status
@@ -1251,11 +1255,11 @@ unittest {
 	enum FuncId = "vibe.web.rest.__unittestLXXXX_XXX.IGithubPR.getPullRequests";
 	enum msg = ": Path contains ':owner', but not parameter '_owner' defined.";
 
-	@rootPath("/repos/")
-		interface IGithubPR {
-			@path(":owner/:repo/pulls")
-			string getPullRequests(string owner, string repo);
-		}
+	@path("/repos/")
+	interface IGithubPR {
+		@path(":owner/:repo/pulls")
+		string getPullRequests(string owner, string repo);
+	}
 	static assert(getInterfaceValidationError!(IGithubPR)
 		      && msg == getInterfaceValidationError!(IGithubPR)[FuncId.length..$],
 		      getInterfaceValidationError!(IGithubPR));