mongodb

The Mongodb plugin enables lightweight access to Mongodb databases. This plugin does NOT provide domain classes nor dynamic finders like GORM does.

Usage

Upon installation the plugin will generate the following artifacts in $appdir/griffon-app/conf:

• MongodbConfig.groovy - contains the database definitions.
• BootstrapMongodb.groovy - defines init/destroy hooks for data to be manipulated during app startup/shutdown.

A new dynamic method named withMongodb will be injected into all controllers, giving you access to a com.gmongodb.GMongo object, with which you'll be able to make calls to the database. Remember to make all database calls off the EDT otherwise your application may appear unresponsive when doing long computations inside the EDT.

This method is aware of multiple databases. If no databaseName is specified when calling it then the default database will be selected. Here are two example usages, the first queries against the default database while the second queries a database whose name has been configured as 'internal'

package sample
class SampleController {
    def queryAllDatabases = {
        withMongodb { databaseName, database -> ... }
        withMongodb('internal') { databaseName, database -> ... }
    }
}

This method is also accessible to any component through the singleton griffon.plugins.mongodb.MongodbConnector. You can inject these methods to non-artifacts via metaclasses. Simply grab hold of a particular metaclass and call MongodbEnhancer.enhance(metaClassInstance, mongodbProviderInstance).

Configuration

Dynamic method injection

The withMongodb() dynamic method will be added to controllers by default. You can change this setting by adding a configuration flag in griffon-app/conf/Config.groovy

griffon.mongodb.injectInto = ['controller', 'service']

Events

The following events will be triggered by this addon

• MongodbConnectStart[config, databaseName] - triggered before connecting to the database
• MongodbConnectEnd[databaseName, database] - triggered after connecting to the database
• MongodbDisconnectStart[config, databaseName, database] - triggered before disconnecting from the database
• MongodbDisconnectEnd[config, databaseName] - triggered after disconnecting from the database

Multiple Stores

The config file MongodbConfig.groovy defines a default database block. As the name implies this is the database used by default, however you can configure named databases by adding a new config block. For example connecting to a database whose name is 'internal' can be done in this way

databases {
    internal {
        host = 'server.acme.com'
    }
}

This block can be used inside the environments() block in the same way as the default database block is used.

Example

A trivial sample application can be found at https://github.com/aalmiray/griffon_sample_apps/tree/master/persistence/mongodb

Testing

The withMongodb() dynamic method will not be automatically injected during unit testing, because addons are simply not initialized for this kind of tests. However you can use MongodbEnhancer.enhance(metaClassInstance, mongodbProviderInstance) where mongodbProviderInstance is of type griffon.plugins.mongodb.MongodbProvider. The contract for this interface looks like this

public interface MongodbProvider {
    Object withMongodb(Closure closure);
    Object withMongodb(String serverName, Closure closure);
    <T> T withMongodb(CallableWithArgs<T> callable);
    <T> T withMongodb(String serverName, CallableWithArgs<T> callable);
}

It's up to you define how these methods need to be implemented for your tests. For example, here's an implementation that never fails regardless of the arguments it receives

class MyMongodbProvider implements MongodbProvider {
    Object withMongodb(String serverName = 'default', Closure closure) { null }
    public <T> T withMongodb(String serverName = 'default', CallableWithArgs<T> callable) { null }
}

This implementation may be used in the following way

class MyServiceTests extends GriffonUnitTestCase {
    void testSmokeAndMirrors() {
        MyService service = new MyService()
        MongodbEnhancer.enhance(service.metaClass, new MyMongodbProvider())
        // exercise service methods
    }
}