Question

I have a “comments” String field in my domain. On each save or update of the field I want to check if the field contains a sub string that matches a String from another field of the same domain (or different domain for that matter). I need to run through all the instances of that field to see if there is a match. If it matches I want to transform it into a link inside the comments field to a show action for that entry matching the sub string.

So for example, a comments field for a product with a serial number would note if the product has been replaced by another one by giving it’s serial number in the comments field. Like: “This product was replaced by SN1234”. I want to automatically transform SN1234 into a link to show the product with serial number SN1234.

What is the best way to go about this ? In the controller, in the GSP ? How ?

Answer 1

As long as the column you’re trying to match on is indexed, you’ll just need to do a query for the match and if found, modify your comment to include the URL. Controller or Service doesn’t really matter for the lookup (although I would probably put it in a service). You’ll want to be sure the search is not transactional so it will be as fast as it can be. No way I would do any of this in a GSP.

To insert the link, you could a simple find and replace. Once you know which text you want turned into the link, pseudo code follows:

def comment = "This product was replaced by SN1234" 
def match = "SN1234"
def link = g.link(action: "show", controller: "product", id: "${product.id}", match)
comment = comment.replace(match, link)

Which you would then end up with

"This product was replaced by <a href='/product/1234'>SN1234</a>"

There may be more efficient ways to do this, but this is a good place to start.