Getting closer

As I'm getting closer to finishing up the essential code for GrailsCrowd, I noticed that I'm doing on the fly refactorings more seamlessly than I was able to do when I first started hacking with Groovy/Grails. And Groovy Closures are my friends these days :-)

Here's a small example from the GrailsCrowd code base - 2 simple controller actions to query for Grails projects by tags, only with the difference that the first action gets all the projects within a system for a specified tag (globally) and the other one gets projects for a tag for a specific member. Both actions operate on the Tag instance, so I refactored the common functionality of querying for Tags into a method which takes a closure:

class GrailsProjectController {
 
  ...
  private def withTag(callable) {
       if (!params.selectedTag) {
           redirect(uri: '/notAllowed')
       }       
       def tag = Tag.findByName(params.selectedTag)
       callable(tag)
   }
   ...
}

And then the above mentioned actions became:

class GrailsProjectController {
 
  ...
  def findByTagGlobally = {
       def total = 0
       def projects = []
       withTag {tag ->
           if (tag) {
               total = Tagging.countByTag(tag)
               //Using CrieteriaBuilder here, so we could query by 'taggings' association
               projects = GrailsProject.createCriteria().list(params) {
                   taggings {
                       eq('tag', tag)
                   }
               } //Criteria builder
               //Sort by name since GrailsProject implements Comparable and the name property is its natural order
               projects.sort()

           } //if
       } //Closure
       render(view: 'list', model: [projects: projects, navMenu: 'discoverNavigationByTag',
               paginatingController: controllerName, paginatingAction: actionName, total: total,
               menuContext: [tag: params.selectedTag]])
   }
  
   def findByTagForMember = {
       def total = 0
       def projects = []
       def member = Member.findByName(params._name)
       withTag {tag ->
           if (tag) {
               if (!member) {
                   redirect(uri: '/notAllowed')
               }
               total = Tagging.countByTagAndMember(tag, member)
               //Using CrieteriaBuilder here, so we could query by 'taggings' association
               projects = GrailsProject.createCriteria().list(params) {
                   taggings {
                       eq('tag', tag)
                       eq('member', member)
                   }
               } //Criteria builder
               //Sort by name since GrailsProject implements Comparable and the name property is its natural order
               projects.sort()
           } //if
       } //Closure
       render(view: 'list', model: [projects: projects, navMenu: 'memberProjectsNavigationByTag',
               paginatingController: controllerName, paginatingAction: actionName, total: total,
               menuContext: [tag: params.selectedTag, member: member]])
   }
   ...
}

Also notice the use of GORM CriteriaBuilder which allowed to nicely query m:n 'Tagging' association class!

Keep Groovying.

Later...