Comments on: Neo4j Grails Plugin

By: Stefan Armbruster

Stefan Armbruster — Sat, 03 Oct 2009 16:13:39 +0000

withTransaction is part of the domain class extensions being provided by the persistence plugin. The Neo4j plugin currently does not implement this.

By: Mustang

Mustang — Sat, 03 Oct 2009 13:29:39 +0000

This is more elegant, does it work too?

http://grails.org/doc/1.1.x/ref/Domain%20Classes/withTransaction.html

By: Stefan Armbruster

Stefan Armbruster — Sat, 03 Oct 2009 10:56:34 +0000

Every call to the Neo API has to be done within a transaction. During normal requests the plugin uses a similar approach to Hibernate's OpenSessionInView with the difference that it opens a Transaction. This works fine so far, but I think there might be a better solution. Regarding your question, here's a Bootstrap.groovy from one of my internal projects:

import org.springframework.transaction.PlatformTransactionManager
import org.springframework.transaction.support.TransactionTemplate
import org.springframework.transaction.support.TransactionCallback

class BootStrap {

     PlatformTransactionManager transactionManager

     def init = { servletContext ->

         def result = new TransactionTemplate(transactionManager).execute({ status ->
             // setup Roles
             if (!Role.list()) {
                 log.error "added roles"
                     new Role(authority:"ROLE_USER").save()
             }
         } as TransactionCallback)
     }
     def destroy = {
     }
}

By: Stig Lau

Stig Lau — Sat, 03 Oct 2009 10:00:22 +0000

Very nice, worked like a charm.
The next question is; do you have an example of what the code has to look like when you write it in “grails console” or grails-app/conf/BootStrap?

My test:
new Car(colour:”Blue”).save()

Results in:
Exception thrown: No transaction found for current thread
org.neo4j.api.core.NotInTransactionException: No transaction found for current thread
at org.neo4j.impl.persistence.PersistenceManager.getCurrentTransaction…

I believe this has to be done in the context of a transaction, and Grails doc does not tell me how.

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By: Armbruster IT Blog » Example for using Neo4j with Grails

Armbruster IT Blog » Example for using Neo4j with Grails — Fri, 02 Oct 2009 20:07:02 +0000

[...] reply to my today’s annoncement of the Neo4j Grails plugin, @StigLau asked me to provide an example for using the Neo4j Grails [...]

By: Tweets die Armbruster IT Blog » Neo4j Grails Plugin erwähnt -- Topsy.com

Tweets die Armbruster IT Blog » Neo4j Grails Plugin erwähnt -- Topsy.com — Fri, 02 Oct 2009 17:18:38 +0000

[...] Dieser Eintrag wurde auf Twitter von Peter Neubauer und darthvader42 erwähnt. darthvader42 sagte: just release the initial version of the #neo4j #grails plugin: http://bit.ly/d74uQ [...]