Creating REST enabled Swing mashups just got a bit easier. I'm happy to announce that a REST plugin is now available for Griffon. This plugin wraps handy client and builder classes provided by the awesome HTTPBuilder project.

Let me walk you through a simple example. It seems that nowadays a Twitter demo is the way to go so let's follow that path. We'll build a trivial application that will query the followers of an authenticated user, these are the steps:

1. First, grab a copy of Griffon 0.2-BETA (or newer) if you haven't done so already.
   
   
2. Let's create the app, type griffon create-app gritter on your command prompt.
   
   
3. Go into the app's directory and type griffon install-plugin rest, this will install the latest version of the REST plugin.
   
   
4. Edit griffon-app/models/GritterModel.groovy by adding the following text
   import groovy.beans.Bindable import ca.odell.glazedlists.EventList import ca.odell.glazedlists.BasicEventList import ca.odell.glazedlists.SortedList import java.beans.PropertyChangeListener class GritterModel { @Bindable String username @Bindable String password @Bindable boolean enabled = false EventList followers = new SortedList( new BasicEventList(), {a, b -> a.name <=> b.name} as Comparator) GritterModel() { addPropertyChangeListener({ e -> if(e.propertyName == "enabled") return if(username && password) enabled = true } as PropertyChangeListener) } }
   
5. Edit griffon-app/views/GritterView.groovy, add the following text
   import ca.odell.glazedlists.* import ca.odell.glazedlists.gui.* import ca.odell.glazedlists.swing.* import net.miginfocom.swing.MigLayout def createTableModel() { def columnNames = ["Name", "Location"] new EventTableModel(model.followers, [ getColumnCount: {columnNames.size()}, getColumnName: {index -> columnNames[index]}, getColumnValue: {object, index -> object."${columnNames[index].toLowerCase()}" }] as TableFormat) } actions { action(id: "lookupFollowersAction", name: "Lookup followers", enabled: bind{ model.enabled }, closure: controller.lookupFollowers) } application(title:'gritter', size:[320,400], locationByPlatform: true, iconImage: imageIcon('/griffon-icon-48x48.png').image, iconImages: [imageIcon('/griffon-icon-48x48.png').image, imageIcon('/griffon-icon-32x32.png').image, imageIcon('/griffon-icon-16x16.png').image]) { panel(layout: new MigLayout("fill","[left]")) { label("Credentials", constraints: "split, span, gaptop 10") separator( constraints: "growx, wrap, gaptop 10") label("Username:") textField(columns: 30, constraints: "wrap", text: bind(target: model, targetProperty: "username", mutual: true)) label("Password:") passwordField(columns: 30, constraints: "wrap", text: bind(target: model, targetProperty: "password", mutual: true)) button(lookupFollowersAction, constraints: "span, grow, wrap") label("Followers", constraints: "split, span, gaptop 10") separator(constraints: "growx, wrap, gaptop 10") scrollPane(constraints: "span, grow, wrap") { table(id: "followersTable", model: createTableModel()) } new TableComparatorChooser(followersTable, model.followers, AbstractTableComparatorChooser.SINGLE_COLUMN) } }
   
6. Fetch a copy of GlazedLists and MigLayout and place them inside $basedir/lib. That should take care of all required dependencies.
   
   
7. Edit griffon-app/controllers/GritterController.groovy, this is where the magic happens
   class GritterController { def model def lookupFollowers = { evt = null -> model.enabled = false doOutside { try { withRest(id: "twitter", uri: "http://twitter.com/statuses/") { auth.basic model.username, model.password def response = get(path: "followers.json") def followers = [] if(response.status == 200) { response.data.each { user -> followers << [name: user.screen_name, location: user.location ?: ""] } doLater { model.followers.clear() model.followers.addAll followers } } else { // TODO display an error dialog } } } finally { doLater {model.enabled = true } } } } }The Rest plugin will inject a few dynamic methods, withRest() is one of them. This method uses a RESTClient under the covers. Notice that the Twitter request is performed outside the EDT, followers are collected on a background thread, then the model is updated inside the EDT.
   
   
8. Run the application by typing griffon run-app. Upon entering valid Twitter credentials you should see a similar screen like the following one
   
   
   
   
That's it! The plugin comes with other nifty features like reusable clients (using an id: property) and proxy settings shortcuts. Feedback is always appreciated.

Keep on Groovying!