Parallel.js

This looks some interesting tech, I should investigate more

Parallel.js

Technology Lead

Since taking on a new role as a technology lead in the digital marketing space I have had less and less to do with Grails and Groovy directly.
So I am going to branch out a bit on this blog to include all technology.

Grails dbconsole

A feature I have never used in Grails is the h2 web browser. A great way to see what the db structure and what the data looks like. This allows you to easily see the db structure your domain classes boil down to.

If you are running an application at

localhost:8080/appname

 You can browse to

localhost:8080/appname/dbconsole

For the JDBC URL use the setting from your DataSource.groovy in my case

jdbc:h2:mem:devDb

 And there we go all domain objects visible. Not only can you run sql queries but you can insert, modify, delete.

Using ExpandoMetaClass in unit tests

There is great power in the ExpandoMetaClass, particularly when doing unit tests.
I want to unit test a specific Domain but it uses a service (in this case springSecurityService.encodePassword()) in one of its methods (protected void encodePassword). Rather than have an integration test or mock out the whole service I can just override a method on the fly. This allows me to just test the logic I am interested in.

The code in my test looks like this.

    void setUp() {
        println "setUp()"
        User.metaClass.encodePassword = {->
            password
        }
       
        def user = new User(username: 'user', enabled: true, password: '123').save(flush: true)
        assert user
    }

What I have done is overridden the method encodePassword on the class User.

Domain event features

The Grails Domain class has some really nice event features in the afterUpdate, beforeUpdate.
What I wanted was if the domain.status was set to completed then domain.completedDate would be filled in with the current date. And if the domain.status was set to anything else, then domain.completedDate would be made null.
Was pretty easy to add this code to the domain

    def afterUpdate() {
        if (status == Status.COMPLETED) {
        if (completedDate)
        completedDate = new Date()
        } else {
        completedDate = null
        }
   }

Groovy Enums

Found a neat trick for matching a String back to its enum. For instance if we have the following enum

public enum Status {
INBOX { public String toString() {"Inbox"}},
NEXT { public String toString() {"Next Action"}},
SOMEDAY { public String toString() {"Someday"}} }

 So if you had a String and wanted to match the enum it is as easy as

def a = "Inbox" as Status

Groovy vs Java

Performance Test: Groovy 2.0 vs. Java

Groovy is catching up performance wise. Though speed has never really been it's goal.
I still maintain pure speed is not that important, and you can always drop down to pure Java.