"Conditional" field layout - hiding or showing fields based on another field is it somehow possible to conditionally show or hide fields in the entry editor based on the value of another previously entered field? 

An example of this use would be:


A section has Lightswitch field "hasVideo"
User is populating a new entry for this section and sets "hasVideo" to the value of choice.
If user sets hasVideo to true, show a text field "productVideo" so that the user can set a link to a youtube video, but hide assets field "productImage".
If user sets hasVideo to false, how Assets field "productImage" so that the user can upload an image, but hide "productVideo" field.


This would really help from a usability perspective since the client will only be shown the fields that need to be filled based on what was filled earlier on - creating a sort of entry creation "wizard". 

Naturally there might be an alternative route to achieve the same level of usability that I'm missing.

Thanks in advance!
The feature request for this has been very popular since day one, so hopefully it's something P&amp;T adds to the core some day.

For the interim I just published a small plugin called Reasons, which will add simple field/value based conditionals to entry type field layouts - pretty much exactly like the OP describes it.

Download from GitHub: https://github.com/mmikkel/Reasons-Craft

Edit
P&amp;T retired the UserVoice page; here is the new home for the feature request