I'm in the need to create a custom field type that renders like a LinkValue field. Instead of forwarding the browser to a different page, I would like to execute JavaScript code (in order to use OpenPopUpPage) depending on several parameters (maybe stored in SPFieldMultiColumnValue?).
What is the best way to approach the requirement?
This has to be the best reference on custom field types from Bjorn Furuknap
Customizing the User Experience of SharePoint: Custom fields deep dive
There is some pain involved in custom fields types though, in his own words