Building architecture, allowing modular addition of services.

Makefile

@@ -1,6 +1,6 @@
 NAME = webshell.exe
 
-SRC  = parser.opa editor.opa webshell.opa login.opa facebook.opa search.opa dropbox.opa config.opa
+SRC  = service.opa parser.opa editor.opa webshell.opa login.opa facebook.opa search.opa dropbox.opa config.opa
 SRCS = $(SRC:%=src/%)
 
 all: $(NAME)

src/dropbox.opa

@@ -123,8 +123,8 @@ Please re-run your application with: --dropbox-config option")
   function ls() {
     match (get_creds()) {
       case {some: creds}:
-        acc_info = DB.Account.info(creds)
-        Log.info("Dropbox", "Account info: {acc_info}")
+        files = DB.Files("dropbox", "/").metadata(DB.default_metadata_options, creds)
+        Log.info("Dropbox", "Files: {files}")
       default:
         authentication_failed()
     }

src/service.opa

@@ -0,0 +1,67 @@
+// license: AGPL
+// (c) MLstate, 2011, 2012
+// author: Adam Koprowski
+
+ // service response to a command
+type Service.response('t) =
+  { xhtml response, 't new_state }
+
+ // specification of a single service
+type Service.spec('t) =
+  { 't initial_state,
+    ('t -> Parser.general_parser(Service.response('t))) parse_cmd
+  }
+
+ // implementation of a service
+abstract type Service.t =
+  Cell.cell(string, {cannot_handle} or {xhtml response})
+
+server module Service {
+
+   // builds a service from its specification
+  function Service.t make(Service.spec('t) spec) {
+    function process_cmd(state, cmd) {
+      cmd_parser = spec.parse_cmd(state)
+      match (Parser.try_parse(cmd_parser, cmd)) {
+      case {some: res}:
+        { return: {response: res.response},
+          instruction: {set: res.new_state}
+        }
+      default:
+        { return: {cannot_handle},
+          instruction: {unchanged}
+        }
+      }
+    }
+    Cell.make(spec.initial_state, process_cmd)
+  }
+
+}
+
+// implementation of a system (consisting of a bunch of services)
+abstract type System.t = list(Service.t)
+
+server module System {
+
+  function System.t build(list(Service.t) services) {
+    services
+  }
+
+  function xhtml process(System.t sys, string cmd) {
+    recursive function aux(services) {
+      match (services) {
+      case []:
+          <>Unknown command</>
+      case [x | xs]:
+        match (Cell.call(x, cmd)) {
+        case ~{response}:
+          response
+        default:
+          aux(xs)
+        }
+      }
+    }
+    aux(sys)
+  }
+
+}

src/webshell.opa

@@ -3,7 +3,7 @@
 // author: Henri Binsztok
 // author: Adam Koprowski (adding Facebook-connectivity)
 
-import stdlib.themes.bootstrap
+import stdlib.themes.bootstrap.v1.4.0
 import stdlib.widgets.bootstrap
 
 WB = WBootstrap