Im looking at trying to add validation to a DataObject using the ImageDataObjectManager. Basically I want to verify if an Image width and size is correct before allowing a file to be uploaded. However I am stumped as in where I need to add this, I thought using the getCMSValidator method in the DataObject would work but doesn't seem to even be recognised using the ImageDataObjectManager at all.
I noticed that there is a setDetailFormValidator which is from ComplexTableField but doesn't seem to actually work with what I want to do (again didnt seem to be recognised).
There's only one way to do that and it's not too easy. You need to set up a custom controller with a handleswfupload() method and do the validation there. If you need some help with it, you can contact me through my website to schedule a time for hands-on support.
Thanks UncleCheese, I seem to have it sort of working now. However the current way I have it working is to output a a string with just a space. This causes the upload to fail (which is correct) however a minor annoyance is that i can add files to the list but cannot actually upload any files anymore unless I close the popup window and do it again.