> For the complete documentation index, see [llms.txt](https://ondrej-kvasnovsky-2.gitbook.io/vaadin-on-grails-3/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ondrej-kvasnovsky-2.gitbook.io/vaadin-on-grails-3/chapter1/plugin_configuration.md).

# Plugin Configuration

When we add dependency to [Vaadin plugin](http://grails.org/plugin/vaadin) into `BuildConfig.groovy` and run `gradle quick-start` or `gradle quick-start-spring` the plugin generates the following files inside our Grails application.

* `MyUI.groovy` - main Vaadin UI file
* `VaadinConfig.groovy` - is main configuration file for Vaadin application

And removes URL mapping from UrlMapping.groovy.

## VaadinConfig.groovy

Vaadin configuration file `grails-app/conf/VaadinConfig.groovy` contains all the configuration that is required by the plugin.

We will explore what all can be configured in `VaadinConfig.groovy`.

### mappingExtras

We need to define extra mapping in case we need to 'reserve' a URL that should not be mapped to, for example, `/*` by Vaadin.

For example, we need to enable [console](http://grails.org/plugin/console) plugin. First we add plugin dependency `compile ":console:1.4.4"` into `BuildConfig.groovy`.

Then we provide mapping for `/console/*` pattern.

```
mappingExtras = [
    '/console/*'
]
```

To get console plugin working, you need to apply [this hack](https://github.com/ondrej-kvasnovsky/grails-console/commit/f2e302d879e8c8ba1643f78b4cf3e78f21984e6e).

### productionMode

When [production mode](https://vaadin.com/book/vaadin6/-/page/advanced.debug-production-modes.html) is set to false, it enables debug mode. So, we can easily inspect application in browser by adding `?debug` to the end of URL.

By default, the productionMode is set to false also inside Grails.

```
productionMode = false
```

In order to enable `productionMode` in production, make sure the following code is present.

```
environments {
    production {
        vaadin {
            productionMode = true
        }
    }
}
```

### asyncSupported

Set this property to true to enable asynchronous communication, so you can use [Vaadin push](https://vaadin.com/book/vaadin7/-/page/advanced.push.html).

```
asyncSupported = true
```

### themes

You can provide name of the [themes](https://vaadin.com/book/vaadin7/-/page/themes.creating.html), which is a directory name in web-app/VAADIN/themes folder.

```
themes = ['sample']
```

### sassCompile

You can specify exact version of Vaadin for SASS compilation.

```
sassCompile = '7.6.1'
```

### widgetset

In order to use your own widget set, for example, if you need to use add-ons.

```
widgetset = 'com.mycompany.widgetset'
```

If `widgetset` is not set, the default widget set from Vaadin is used.

### servletClass

There is a default servlet, [`com.vaadin.grails.server.DefaultServlet`](https://github.com/ondrej-kvasnovsky/grails-vaadin-plugin/blob/master/grails-vaadin7-plugin/src/groovy/com/vaadin/grails/server/DefaultServlet.groovy), provided by Vaadin plugin that makes actually possible to run Vaadin inside Grails.

If you need to create your own servlet, you can do it by extending [`com.vaadin.grails.server.DefaultServlet`](https://github.com/ondrej-kvasnovsky/grails-vaadin-plugin/blob/master/grails-vaadin7-plugin/src/groovy/com/vaadin/grails/server/DefaultServlet.groovy). Then set `servletClass` to your custom servlet.

```
servletClass = "com.app.MyGrailsAwareApplicationServlet"
```

### packages

We can define a package name where Spring will search for components.

```
packages = ['com.mycompany.vaadin']
```

This is optional, all packages will get scanned by default.

### uiProvider

We can create own implementation of [`com.vaadin.server.UIProvider`](https://vaadin.com/wiki/-/wiki/Main/Creating+an+application+with+different+features+for+different+clients).

```
uiProvider = "com.mycompany.MyGrailsAwareUIProvider"
```

This is optional, default is [`com.vaadin.grails.server.DefaultUIProvider`](https://github.com/ondrej-kvasnovsky/grails-vaadin-plugin/blob/master/grails-vaadin7-plugin/src/groovy/com/vaadin/grails/server/DefaultUIProvider.groovy).

### openSessionInViewFilter

In order to activate Open Session in View for Hibernate 3.

```
openSessionInViewFilter = 'org.springframework.orm.hibernate3.support.OpenSessionInViewFilter'
```

Or this for Hibernate 4.

```
openSessionInViewFilter = 'org.springframework.orm.hibernate4.support.OpenSessionInViewFilter'
```


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