Question

I have just gotten started with Grails and I have a very basic application running. I want to pre-populate a hidden form field with a random string.

What is the best way to do this? I have looked at the taglib but I am not sure what the best practice is for this sort of thing. Should I create a class in the src/java or src/groovy folder or is there a better way to get this done?

Lastly, and I know this is a very basic question, but if I do create a class or taglib, how exactly is that called from within the .gsp page?

Thanks!

Answer 1

If your action looks like this

def create() { [orgInstance: new Org(params)] }

it means that a new Org object is passed to your view which can be referenced as orgInstance

Since the model [orgInstance: new Org(params)] is a map, you can simply add another parameter:

def create() { [orgInstance: new Org(params), hiddenValue: 'something random'] }

This can be used in your .gsp in the following way:

<input type="hidden" name="test" value="${hiddenValue}" />

Regarding your other question: a custom taglib is used in the same way as the other Grails-Tags: <g:myTag ...>...</g:myTag> . You can change the namespacegto whatever you like -g` is the default. See the documentation for more details: http://grails.org/doc/latest/ref/Tag%20Libraries/Usage.html