Vaadin Grails Plugin

Daniel · August 10, 2009, 7:20am

Hi All,
I finally tried integrating Vaadin with Grails to see if it was possible to develop a Vaadin application without having to constantly redeploy in order to see my progress. The result is a new Vaadin Grails plugin, and I was very impressed with the increase in productivity. For details, check out the plugin
here
, or install the it in your Grails app like this:

grails install-plugin vaadin

Have fun!

Daniel

Henry · August 10, 2009, 8:55am

Great work Daniel!

Henry · August 10, 2009, 9:03am

Added a short notice about it on the wiki:
http://vaadin.com/wiki/-/wiki/Main/Grails%20plugin

Daniel · August 10, 2009, 9:21am

Thanks Henry

Joe1 · September 14, 2009, 3:59pm

Daniel,

Can you post a simple Hello World on integrating Vaadin and Grails using your plugin?

Also, what are your plans for maintaining the plugin, going forward … as new versions of Vaadin and Grails become available?

Joet

Daniel · September 27, 2009, 8:11am

Hi Joe,
My original plans for the plugin were dependent on the response that it received. Recently a few people have requested information about the plugin, so I’ve decided to actively maintain it, starting this week. You can track my progress, or vote for features or issues for the plugin
on its Codehaus JIRA page
. My first priority is to update the plugin to the latest version of Vaadin. After that, I plan to write a Hello World example and post it
on the wiki here
. Hopefully that will be some time this week.

Regards,
Daniel

Michael2 · October 4, 2009, 11:50am

Hi Daniel,

I tried Vaadin Grails Plugin but I get following exception when accessing a one-to-one|many mapped relation in Vaadin application. Did you ran into same issue? Are there any workarounds? It may be related to http://jira.codehaus.org/browse/GRAILS-5076 but I’m not sure. Thanks!

Michael

java.lang.RuntimeException: javax.servlet.ServletException: org.hibernate.LazyInitializationException: could not initialize proxy - no Session
at com.opensymphony.sitemesh.webapp.decorator.BaseWebAppDecorator.render(BaseWebAppDecorator.java:40)
at org.codehaus.groovy.grails.web.sitemesh.GrailsPageFilter.doFilter(GrailsPageFilter.java:135)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.codehaus.groovy.grails.web.servlet.filter.GrailsReloadServletFilter.doFilterInternal(GrailsReloadServletFilter.java:101)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:76)
…

Daniel · October 5, 2009, 10:52am

Hi Michael,
I’ve not come across the problem you’re describing while working with Vaadin in Grails. I have come across the same error in other applications though. Usually I’ve been able to fix them by changing the relationship to use eager loading instead of lazy loading, or accessing the collection that defines the relationship while the Hibernate session is still open.

Cheers,
Daniel

Daniel · October 5, 2009, 10:56am

Hi Joe,
I just posted a simple Hello World application to the wiki
here
that uses the current version of the plugin. I’ve added some extra features to the plugin over the past week, and I’ll be releasing it as soon as I get the chance to test it properly.
Cheers,
Daniel

Lars1 · December 3, 2009, 11:34am

Hi Daniel,

Thank you for the Vaadin Grails plugin and an overall great tutorial. It is really cool way to enable the developer to write Vaadin apps with Groovy. I do however have some problems using e.g. Button events within the Groovy/Vaadin setup. Is there anyway for you to extend the Hello World example and show how to use events within Groovy/Vaadin?

Kind regards,

Lars

Peter10 · February 14, 2010, 1:00pm

Hi,

and foremost, thanks for providing the grails plugin.

However, I have a somewhat trivial newb question, which relates more to grails than Vaadin, though. How do you inject a grails service so that it can used in the Vaadin Application class?

A simple:

class MyApplication extends Application {
   def someService

   ....
}

doesn’t seem to work. someService is null when I call it. Any ideas how to solve this?

Peter10 · February 15, 2010, 7:29pm

Nevermind, I found a solution for this. I’ll share it, as this might save someone a minute or two.

You can get a handle to your service, for example, by using a factory class like this:

import org.codehaus.groovy.grails.commons.ApplicationHolder

class ServiceFactory {

    def getSomeService() {
        return this.getBean('someService')
    }

    private def getBean(beanName) {
        return ApplicationHolder.getApplication().getMainContext().getBean(beanName)
    }

}

Then you would use this class in a vaadin component, like this:

...
def serviceFactory = new ServiceFactory()
def service = serviceFactory.getSomeService()
...

nat-nat · February 26, 2010, 5:04am

Vaadin plugin is already working but I want to access grails controllers from the browser?
how can we access grails domain objects or controllers like the (index,list,etc…) ?

nat-nat · March 2, 2010, 5:55am

Hi Daniel,

How can we change the URL mapping on Vaadin application so that I could access grails controller in the browser.

Actually I could now access grails controllers and vaadin application in the browser by changing the url mapping
in VaadinGrailsPlugin.groovy from “/" into "/VAADIN/”.

If I change it to other pattern like “/MainApp/" , I get widgetset not loaded error. It only works on this pattern ("/VAADIN/”).

def servletMappings = webXml.“servlet-mapping”
servletMappings[servletMappings.size() - 1]

{
“servlet-mapping” {
“servlet-name”(“VaadinServlet”)
“url-pattern”(“/VAADIN/*”)
```
     }
 }
```

Is there other way I could change this pattern (“/VAADIN/*”) to access grails controller and access vaadin application

Thanks

nat nat

Drew · March 13, 2010, 4:47am

I used your modifications to the plugin as a starting point, with the following changes:

Update the web.xml generation to set the URL mapping from a config property, instead of always using “/*” (otherwise it won’t play well with Grails controllers; it prevents you from ever seeing them).
Added another url mapping using the vaadin servlet to the URL pattern “/VAADIN/*”. Without this, you can never reach the widgetset URLs and your Vaadin app won’t run.

Hope that helps!

nat-nat · March 15, 2010, 6:53am

What are the class I need to change or update? or do have a any code sample or a script we could follow?

Thanks.

Abiel · April 19, 2010, 4:39am

Thank you very much Daniel,
VGrails framework uses your plugin in a very intensive way

http://vaadin.com/forum/-/message_boards/message/146536

Abiel
@West Java, Indonesia

Drew · April 21, 2010, 6:07am

It’s the VaadinGrailsPlugin.groovy file that has to change, which is what manipulates the web.xml. Here’s a snippet of the main change, though I also modified the logging block under “getConfig” to show the currently configured urlValue.


        def vaadinApplicationClass = config.applicationClass
        def vaadinProductionMode = config.productionMode
		def vaadinUrlPattern = config.urlPattern
		
        def contextParams = webXml."context-param"
        contextParams[contextParams.size() - 1]
 +  {
                        "context-param" {
                            "description"("Vaadin production mode")
                            "param-name"("productionMode")
                            "param-value"(vaadinProductionMode)
            }
        }

        def servlets = webXml."servlet"
        servlets[servlets.size() - 1]
 +  {
                    "servlet" {
                            "servlet-name"("VaadinServlet")
                            "servlet-class"("com.vaadin.terminal.gwt.server.GrailsAwareApplicationServlet")
                            "init-param" {
                                    "description"("Vaadin application class to start")
                                    "param-name"("application")
                                    "param-value"(vaadinApplicationClass)
                }
                "load-on-startup"("1")
            }
        }

        def servletMappings = webXml."servlet-mapping"
        servletMappings[servletMappings.size() - 1]
 + {
                    "servlet-mapping" {
                            "servlet-name"("VaadinServlet")
                            "url-pattern"(vaadinUrlPattern)
            }
                    "servlet-mapping" {
                            "servlet-name"("VaadinServlet")
                            "url-pattern"("/VAADIN/*")
            }
        }

krishvaadin · May 3, 2010, 10:40am

Server running. Browse to http://localhost:8090/hello-vaadin
[groovyc]
Compiling 1 source file to
C:\Java\test\GrailsTests\hello-vaadin\target\classes
[groovyc]
Compiling 2 source files to
C:\Java\test\GrailsTests\hello-vaadin\target\classes
[delete]
Deleting directory C:\Documents and
Settings\admin.grails\1.2.1\projects\hello-vaadin\tomcat
2. When I load the page in browser, the page is sometimes unavailable
(error 503).
Maybe this has something to do with the first problem.
Has anyone seen the same problem?

Daniel · May 18, 2010, 2:55pm

Hey Abiel,
Thanks for the feedback . I’m glad it’s been useful for you. Congratulations on VGrails: it looks great!
Daniel