UPDATE (04/2008): Magnum hoc blog introitu ostendit a bono javascript dicentur aditus ad hoc problema: http://webborg.blogspot.com/2008/04/add-functions-and-events-to-sharepoint.html

UPDATE II: (04/2008): Hoc blog introitu spectat tam promittens: http://www.cleverworkarounds.com/2008/03/13/free-mosswss-2007-web-part-hide-controls-via-javascript/

Plures temporibus a septimana, si minus quotidie,, forum users describe a requirement that would normally be met via cascading drop-downs. Verbigratia, Habeo duas occumbo-down imperium:

• List of U.S. civitatium
• List of U.S. urbes.

Author UI ut suggero, sic operari volumus:

• Paulus deligit U.S. state from the drop-down.
• This causes the cities drop-down to filter only those cities that belong to the selected state.
• Paulus deligit a civitate hac percolantur album.

There is no out-of-the-box support for this feature. In facto, there is no OOB support for any kind of direct intra-form communication. This includes programmatically hiding/enabling/disabling fields in response to field changes elsewhere on the form.

Hic articulus ad describeret obiectiva rerum solutionum possibilis, et haec sunt bene ut ego cognosco eas,:

1. Develop a custom column type. As a custom-column-developer, you have full control over the "world" of that custom column. You can implement a cascading drop-down that way.
2. Consider using workflow. In some cases, you want to automatically assign a value to field based on another field’s value. In hoc, vos Northmanni conantur uti ratione agmen, sed interdum, it just won’t get the job done. SharePoint Designer workflow is a relatively administer-friendly alternative to dropping down into code and visual studio. If you go this route, Quaestio salutari sentire hoc articulum (http://paulgalvin.spaces.live.com/blog/cns!CC1EDB3DAA9B8AA!405.entry).
3. Tracto vicis: Sicut workflow, this is an after-the-fact solution. Your event handler is a .NET assembly (C #, VB.NET) to which SharePoint passes control. The object you develop has access to the data of the list (et totum illud exemplar,) et potest facere aliquod opus calculus.
4. Use SharePoint Designer to create custom entry forms. I don’t have direct experience with this approach, but I hear they are doing good things with NewForm.aspx these days 🙂
5. Volvite introitu tuo ASP.NET notitia muneris (ut stet-solus textus partem aut paginae) et quod utor instead.

Si quis scit et / vel potius bene, Vestibulum eget velit et corpus, consectetur adipiscing elit felis.

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