Grails link with additional parameters

As I have said before, I love how easy it is to create links in Grails. However, when I was starting out I could never remember the syntax when I needed more information on the URL than just the ID.

Lets say I have a UrlMapping (grails-app/conf/UrlMapping.groovy) of:

"/player/photos/$id?/matchReport/$matchReportId?" {
     controller = "player"
     action = "photos"
 }

I always had problems remembering how to get the matchReportId onto the URL. As with so many things in Grails it turns out to be very simple; use the params parameter:

<g:link controller="player" action="photos" id="${matchPlayer.player.id}" params="[matchReportId:matchPlayer.matchReport.id]">

and good ol’ Grails is smart enough to build the URL like

rfw/player/photos/6/matchReport/26

Creating a link in a Grails Service

I love how easy it is to create a link in Grails but often I want to use this same mechanism to create a link in a Service. For example, I have a service that sends out a News Report to a list of subscribers. There a links in the generated email back to the website.

Creating a link in a service turns out to be quite simple. I found this work around at http://jira.codehaus.org/browse/GRAILS-2605.

def g = new org.codehaus.groovy.grails.plugins.web.taglib.ApplicationTagLib()
 def visitUs = g.createLink(controller: 'site', action: 'index', absolute: 'true')
 def manageSubscriptions = g.createLink(controller: 'comm', action: 'index', absolute: 'true')

The absolute: ‘true’ is really important as I am embedded these links in an email.