Modifying Grails Scaffolded templates – I

In one of the sessions in SpringOne2GX, there was a session on Uber-Scaffolding by Jean Barmarsh. The session was quite incredible and opened up a world of possibilities. We all know that the scaffolded code generated by grails is modifiable if we install the base templates. This is done simply by saying:

[java]grails install-templates[/java]

The above command will create the following directory structure in the application’s src folder

As we can see, there are 3 main directories here :

1. Artifacts: This directory contains all the base files for creating various artifacts. For example, if you say “grails create-domain-class packageName.className”, then the file “src/artifacts/DomainClass.groovy” is taken as the template for creating this file. Same goes for other artifacts like filters, taglibs, controllers, etc.
2. Scaffolding: This directory contains the template files that are used for generating scaffolded code(controllers and views).
3. War : This just contains the web.xml file. If you need to add some configuration block(e.g. session-timeout, etc)

Now there are a lot of things that we may need to modify in the grails templates, the pagination size being one. So, the first change that I did was made the “max” parameter in controller be Config driven simply by replacing :

[java]

params.max = Math.min(params.max ? params.int(‘max’) : 10, 100)

[/java]

by

[java]

int pageSize = grailsApplication.config.grails.scaffolds.pageSize ?: 10
params.max = Math.min(params.max ? params.int(‘max’) : pageSize, 100)

[/java]

This was the simplest thing that was done.

In order to use the changed scaffolding, there are two ways of doing this:

1. [java]grails generate-all MyDomainClass[/java]
2. Create an empty controller, and put the following code in it : [java]def scaffold = MyDomainClass[/java]

Note: When playing around with grails templates, be very careful not to format this code using an IDE. The formatting will add unwanted spaces and the grails create-*/generate-* commands will start failing or produce wrong/unusable files.

Will be back with more 🙂

Regards
~~Himanshu Seth~~

http://www.tothenew.com