Merge: Tnitter: read the latest tnits on the go with the new Tnitter portable app!

Intro a portable client for Tnitter listing the more recent 16 tnits. It is more of a test and example on using `AsyncHttpRequest` to do both simple request to a REST server and implement push notifications using an open request. By design, this client does not support posting Tnits, this feature would require much more code and it may be simplified by future services in the lib.

To support the client the server has a few new REST interfaces. One to list the tnits and the other for push notifications.

This PR also fixes a few bugs on the Tnitter server: losing the session on posting and empty post being accepted by the server.

-----

Note for the reviewers: You may be better to read commits individually. There are 2 bigs commits, one extracts the database logic from the model module and the other introduces code generated by Jwrapper for the native layer of that Android ui implementation.

Pull-Request: #1834
Reviewed-by: Jean Privat <jean@pryen.org>
Reviewed-by: Romain Chanoir <romain.chanoir@viacesi.fr>

Author: privat

contrib/tnitter/.gitignore

@@ -0,0 +1,2 @@
+res/
+tnitter.db

contrib/tnitter/Makefile

@@ -1,3 +1,27 @@
-all:
+SERVER ?= localhost:8080
+
+all: bin/tnitter_server bin/tnitter
+
+bin/tnitter_server: $(shell ../../bin/nitls -M src/tnitter.nit)
 	mkdir -p bin/
-	../../bin/nitc --dir bin src/tnitter.nit
+	../../bin/nitc -o bin/tnitter_server src/tnitter.nit -D tnitter_interface=$(SERVER)
+
+bin/tnitter: $(shell ../../bin/nitls -M src/tnitter_app.nit)
+	mkdir -p bin/
+	../../bin/nitc -o bin/tnitter src/tnitter_app.nit -m linux -D tnitter_server_uri=http://$(SERVER)
+
+android: bin/tnitter.apk
+bin/tnitter.apk: $(shell ../../bin/nitls -M src/tnitter_app_android.nit) res/drawable-ldpi/icon.png
+	mkdir -p bin/
+	../../bin/nitc -o bin/tnitter.apk src/tnitter_app_android.nit -D tnitter_server_uri=http://$(SERVER)
+
+android-release: $(shell ../../bin/nitls -M src/tnitter_app_android.nit) res/drawable-ldpi/icon.png
+	mkdir -p bin/
+	../../bin/nitc -o bin/tnitter.apk src/tnitter_app_android.nit --release -D tnitter_server_uri=http://tnitter.xymus.net
+
+res/drawable-ldpi/icon.png: art/icon.svg
+	mkdir -p res
+	../inkscape_tools/bin/svg_to_icons art/icon.svg --android --out res/
+
+clean:
+	rm -r res bin

contrib/tnitter/art/icon.svg

@@ -0,0 +1,10 @@
+Categories:Nit,Internet
+License:Apache2
+Web Site:http://tnitter.xymus.net/
+Source Code:http://nitlanguage.org/nit.git/tree/HEAD:/contrib/tnitter
+Issue Tracker:https://github.com/nitlang/nit/issues
+
+Summary:Minimal client for the Tnitter open source micro-blogging platform
+Description:
+Read the latest Tnits published on Tnitter and keep up to date with push notification support.
+This is a sample application to do asynchronous HTTP requests from portable Nit code.

contrib/tnitter/net.xymus.tnitter.txt

@@ -10,3 +10,4 @@ git.directory=contrib/tnitter/
 homepage=http://nitlanguage.org
 issues=https://github.com/nitlang/nit/issues
 tryit=http://tnitter.xymus.net/
+apk=http://nitlanguage.org/fdroid/apk/tnitter.apk

contrib/tnitter/package.ini

@@ -18,21 +18,23 @@
 module action
 
 import nitcorn
+import json::serialization
 
 import model
+import database
+
+# Path to the Sqlite3 database
+fun tnitter_db_path: String do return "tnitter.db"
 
 redef class Session
 	# User logged in
 	var user: nullable String = null
 end
 
 # Main Tnitter Action
-class Tnitter
+class TnitterWeb
 	super Action
 
-	var db_path = "tnitter.db"
-	var db = new DB.open(db_path)
-
 	# Header on pages served by this `Action`
 	#
 	# Keywords to `Text::replace`:
@@ -99,6 +101,8 @@ class Tnitter
 		# Error to display on page as a dismissable panel
 		var error = null
 
+		var db = new DB.open(tnitter_db_path)
+
 		# Login/logout
 		if turi == "/login" and request.post_args.keys.has("user") and
 		   request.post_args.keys.has("pass") then
@@ -132,14 +136,16 @@ class Tnitter
 			session = null
 		else if turi == "/post" and request.post_args.keys.has("text") and session != null then
 			var user = session.user
-			if user != null then
+			var text = request.post_args["text"].trim
+			if user != null and not text.is_empty then
 				# Post a Tnit!
-				var text = request.post_args["text"]
 				db.post(user, text)
+				db.close
 
 				# Redirect the user to avoid double posting
 				var response = new HttpResponse(303)
 				response.header["Location"] = request.uri
+				response.session = session
 				return response
 			end
 		end
@@ -203,7 +209,8 @@ class Tnitter
 		else error_html = ""
 
 		# Load the last 16 Tnits
-		var posts = db.latest_posts(16)
+		var posts = db.list_posts(0, 16)
+		db.close
 
 		var html_posts = new Array[String]
 		for post in posts do
@@ -235,3 +242,32 @@ class Tnitter
 		return response
 	end
 end
+
+# Tnitter RESTful interface
+class TnitterREST
+	super Action
+
+	redef fun answer(request, turi)
+	do
+		if turi == "/list" then
+			# list?from=1&count=2 -> Error | Array[Post]
+
+			var from = request.int_arg("from") or else 0
+			var count = request.int_arg("count") or else 8
+
+			var db = new DB.open(tnitter_db_path)
+			var posts = db.list_posts(from, count)
+			db.close
+
+			var response = new HttpResponse(200)
+			response.body = posts.to_json_string
+			return response
+		end
+
+		# Format not recognized
+		var error = new Error("Bad Request")
+		var response = new HttpResponse(400)
+		response.body = error.to_json_string
+		return response
+	end
+end