Friday, May 23, 2008

Grails + email service

Alright, finally getting back into to grails coding after a long time away. For my test pet store application, I decided to take a day and create newsletter sender. Basically, it just takes an email address (submitted via a little form widget thingy), and stores it in a separate table the database. I'm not bothering with user accounts yet for the site, so I'm just keeping it in a stupidly simple table with just a database id and the address itself. There's also a controller function for removing an address from the list (handy I should think).

Now that I've got email addresses to send to, I need to actually send the newsletters. Before tackling that, though, I want to send out the newsletters on a periodic basis, so i need a scheduling/cron like component. I decided to use the Quartz plugin for Grails. We use it at my $DAYJOB, and it's been an excellent workhorse there. After installing the plugin (grails install-plugin quartz), and creating a job (app-home/grails-app/job/SendNewletterJob.groovy), I was 80% done. I just had to define my scheduling and implement the execute() method, which calls my message send service. Easy! Here's my source:

class SendNewsletterJob {
def timeout = 9000l //runs every nine seconds (only for testing!)
def emailService

def execute() {

Now for actually pushing the newsletter to the users. I created an app-home/grails-app/services/EmailService.groovy. In Grails parlance, from what I understand, a "service" is not a web-service (REST or SOAP), per se, but more like the Eric Evans DomainDrivenDesign notion of a service. Currently (May 2008) there is no nice plugin for sending email, but there is a nice document on the Grails site that describes how to create a mechinism that wraps Spring mail. I just ripped off the example EmailService, dropped my smtp host values into my grails-app/conf/spring/resources.xml, and I'm business.

Altogether, this project took less than four hours, most of which was fishing around playing with config settings and such. I'm trying to think what the parallel time investment would have been for a straight-up Java implementation. Hmmmmm.........

Thursday, May 8, 2008

Pat Helland speech

Wow - another reason why Pat is truly one of my heros: Speech from 2007 TechEd EMEA