Hi Vicente and welcome to our :)

Are you trying to expand the fucntionality of Umbraco using your own datatype? Or do I misunderstand?

You should be able to simply define some regex when you define the properties of your document type.

Btw what version of Umbraco are you using?

/Jan

Sorry, I was in a rush on Thursday and I didn't give all the information I should.

Jan, I'm using the Media Picker, not a custom control. I tried using some regex but any of them was use it.

About my second question. I'm using a umbracoUrlAlias and I'd like to check that is unique between the pages. Is it possible?

I'm using Umbraco 4.7.2

Hi Vicente, not really sure you can do the first item because when you save the page the media picker only stores the ID of the associated media item.

What i would look to do is create an extension which fires when you click publish (or save), you would need to create a class that inherits from IApplicationEventHandler and then in the inherited methods you can do something like

        public void OnApplicationStarting(UmbracoApplication httpApplication, ApplicationContext applicationContext)
        {
            Document.AfterSave += Document_AfterSave;
        }

where the Document_AfterSave mehtod is your own code which does the checking, take a look at

http://our.umbraco.org/wiki/reference/api-cheatsheet/using-iapplicationeventhandler-to-register-events

hope that helps

is working on a reply...