Hacking on liftweb 2.5 and sbt 0.12

Tweets about "scala lift"

STEP 1 Download the ‘Lift Basic’ template

prayag@prayag:/backup/workspace.programming/workspace.scala$ git clone git://github.com/lift/lift_25_sbt.git
Cloning into 'lift_25_sbt'...
remote: Counting objects: 881, done.
remote: Compressing objects: 100% (506/506), done.
remote: Total 881 (delta 301), reused 839 (delta 259)
Receiving objects: 100% (881/881), 3.03 MiB | 20 KiB/s, done.
Resolving deltas: 100% (301/301), done.

Going through the liftweb app structure

prayag@prayag:/backup/workspace.programming/workspace.scala/lift_25_sbt/scala_29$ ls -l lift_basic/
total 1100
-rw-rw-r-- 1 prayag prayag    1159 Nov 16 16:33 build.sbt
drwxrwxr-x 2 prayag prayag    4096 Nov 16 16:33 project
-rwxrwxr-x 1 prayag prayag     116 Nov 16 16:33 sbt
-rw-rw-r-- 1 prayag prayag     137 Nov 16 16:33 sbt.bat
-rw-rw-r-- 1 prayag prayag 1103617 Nov 16 16:33 sbt-launch-0.12.jar
drwxrwxr-x 4 prayag prayag    4096 Nov 16 16:33 src

There is sbt-launch-0.12.jar, which means the Lift Basic template comes with a SBT launcher, so there’s no need to install sbt separately.

The src/main structure is 

prayag@prayag:/backup/workspace.programming/workspace.scala/lift_25_sbt/scala_29$ ls -l lift_basic/src/main/
total 12
drwxrwxr-x 3 prayag prayag 4096 Nov 16 16:33 resources
drwxrwxr-x 4 prayag prayag 4096 Nov 16 16:33 scala
drwxrwxr-x 6 prayag prayag 4096 Nov 16 16:33 webapp

The MVC looking architecture of liftweb is 

prayag@prayag:/backup/workspace.programming/workspace.scala/lift_25_sbt/scala_29$ ls -l lift_basic/src/main/scala/code/
total 20
drwxrwxr-x 2 prayag prayag 4096 Nov 16 16:33 comet
drwxrwxr-x 2 prayag prayag 4096 Nov 16 16:33 lib
drwxrwxr-x 2 prayag prayag 4096 Nov 16 16:33 model
drwxrwxr-x 2 prayag prayag 4096 Nov 16 16:33 snippet
drwxrwxr-x 2 prayag prayag 4096 Nov 16 16:33 view

STEP 2 : Building an app
Add Lift and Jetty to project dependencies:
#The build.sbt file is

name := "Lift 2.5 starter template"

version := "0.0.1"

organization := "net.liftweb"

scalaVersion := "2.9.1"

resolvers ++= Seq("snapshots"     at "http://oss.sonatype.org/content/repositories/snapshots",
                "releases"        at "http://oss.sonatype.org/content/repositories/releases"
                )

seq(com.github.siasia.WebPlugin.webSettings :_*)

scalacOptions ++= Seq("-deprecation", "-unchecked")

libraryDependencies ++= {
  val liftVersion = "2.5-M3"
  Seq(
    "net.liftweb"       %% "lift-webkit"        % liftVersion        % "compile",
    "net.liftweb"       %% "lift-mapper"        % liftVersion        % "compile",
    "net.liftmodules"   %% "lift-jquery-module" % (liftVersion + "-2.0"),
    "org.mortbay.jetty" % "jetty" % "6.1.22"    % "container",
    "org.eclipse.jetty" % "jetty-webapp"        % "8.1.7.v20120910"  % "container,test",
    "org.eclipse.jetty.orbit" % "javax.servlet" % "3.0.0.v201112011016" % "container,test" artifacts Artifact("javax.servlet", "jar", "jar"),
    "ch.qos.logback"    % "logback-classic"     % "1.0.6",
    "org.specs2"        %% "specs2"             % "1.12.1"           % "test",
    "com.h2database"    % "h2"                  % "1.3.167"
  )
}

The project/plugins.sbt file is 

libraryDependencies <+= sbtVersion(v => "com.github.siasia" %% "xsbt-web-plugin" % "0.12.0-0.2.11.1")

//Uncoment this line to enable the sbt idea plugin
addSbtPlugin("com.github.mpeltonen" % "sbt-idea" % "1.1.0")

//Uncoment this line to enable the sbt eclipse plugin
addSbtPlugin("com.typesafe.sbteclipse" % "sbteclipse-plugin" % "2.1.0")

The sbt script is 

prayag@prayag:/backup/workspace.programming/workspace.scala/lift_25_sbt/scala_29/lift_basic$ sudo vi sbt


java -Xmx1024M -Xss2M -XX:MaxPermSize=512m -XX:+CMSClassUnloadingEnabled -jar `dirname $0`/sbt-launch-0.12.jar "$@"

The command ‘sbt update ~jetty-run’ will download all necessary libraries (Scala, Lift, Jetty, etc) like mvn install does in maven, compile the application, and then launch Jetty as an embedded application – there’s no need to install Jetty separately, (~jetty-run isn't working in my case).

prayag@prayag:/backup/workspace.programming/workspace.scala/lift_25_sbt/scala_29/lift_basic$ ./sbt update ~jetty-run

STEP 3 : Run app with sbt
sbt tasks can be viewed with $ sbt tasks command.

prayag@prayag:/backup/workspace.programming/workspace.scala/lift_25_sbt/scala_29/lift_basic$ ./sbt
> update
> container:start
[info] Compiling 4 Scala sources to /backup/workspace.programming/workspace.scala/lift_25_sbt/scala_29/lift_basic/target/scala-2.9.1/classes...
[info] 'compiler-interface' not yet compiled for Scala 2.9.1.final. Compiling...
[info]   Compilation completed in 37.636 s
2012-11-16 23:14:24.820:INFO::Logging to STDERR via org.mortbay.log.StdErrLog
[info] jetty-6.1.22
[info] NO JSP Support for /, did not find org.apache.jasper.servlet.JspServlet
[info] Started SelectChannelConnector@0.0.0.0:8080
[success] Total time: 56 s, completed 16-Nov-2012 23:14:30

Open http://localhost:8080 in a web browser to see the application running.


References
Getting Started, https://www.assembla.com/spaces/liftweb/wiki/Getting_Started