====== Spark | Alpha Preview ======

[[Spark|Project Page]] | **SparkAlpha**

Here are some instructions for getting running with the spark preview.

  * SVN: http://svn1.cvsdude.com/osflash/spark/trunk/ 
  * EXPORT: http://dev.codegent.com/spark_export.zip 

  - checkout from svn or download zip above
  - create a mysql db called spark_example
  - edit /webapps/example/WEB-INF/spark.properties and change the db connection details
  - run start.sh (linux/mac) or start.bat (win) in the /bin/ directory.
  - the first time spark loads it will create the db, this is done by the script /webapps/exmaple/WEB-INF/services/PopulateModel.js
  - if it looks like everything is working point your browser at http://localhost:8080/example/resources/remoting-test.swf
  - now you can call the scripts in /webapps/exmaple/WEB-INF/services/ 

===== Right so what does the example do? =====


It shows how scripts work in spark, and different ways you can connect to the database using hibernate in spark. The client is pritty simple, something I built quickly to test the remoting methods. 

===== Exposing remoting methods =====

To expose a method for remoting you use the **meta** object.
This object is only in the context during compile. 

<code javascript>
addMethod(String methodName, String paramTypes, String returnType)
addInterface(String className)
setExtends(String className)

Examples:

// add a business interface, all these methods will be exposed to remoting clients 
meta.addInterface('some.business.package.MyBusinessObject');

// add a method which will be exposed to remoting clients
meta.addMethod('myRemotingFunc','String,Integer','java.util.List');
function myRemotingFunc(someStr,someNum){
  var list = new Packages.java.util.LinkedList();
  list.add(someStr);
  list.add(someNum);
  return list;
}

</code>

Why is this needed? Its used by the compiler to generate a interface used to expose the script to remoting.

===== Script object model =====

This is how scripts access beans in the spring application context, access the http session, etc.

This is exposed to scripts as the **spark** object. Here is the api.

<code javascript>
getCookie(req,name)
getResources(path)
getResource(file)
getMessageSource()
getApplicationContext()
getBeans()
addCookie(cookie)
createCookie(name, value)
getCookieByName(name)
getCookies()
getSession(create)
getSession()

/*
Note: Need to add access to all or part of http request object. DONE in SVN.
Examples:
*/

var isAuth = spark.session.getAttribute('user_auth');
var someService = spark.beans.getBean('serviceInSpring');


</code>

As this java api is called from js you can call get methods as properties so spark.getSession() and spark.session will both work.

===== Logging =====

Each script also has a **log** object. This is just a standard log4j logger. so have all the normal methods. debug(msg), isDebugEnabled() etc. For more info see log4j.

The other option is print() this prints values via System.out.println();. You should try to avoid it.

more info to follow.