Trying to create a popup-menu-based nav structure...

I havea client who is moving to a CMS. I’ve chosen MODx Revolution as the CMS (I’ve used Evo in the past, and MODx seems like the best fit for their needs). However, the client has asked for a very specific navigation system that’s got me stumped.

They want a navigation system based on popup menus. Essentially, imagine this:

There is a Container called "Products." Under that container are resources:
Lawn Mowers
Hedge Trimmers
Laser Cannons

There’s another Container called "Services." Under that container are resources:
Massage
House Painting
Satellite Launching

There’s a third Container called "Men’s Clothing." Under that are resources:
Pants
Shirts
Shoes
Socks
Body Armor

What they want are two popup menus. The first popup menu lists the containers:
Products
Services
Men’s Clothing

The second popup menu automatically updates with all the resources under the chosen container. So if a user clicks on the first popup and chooses Services, the second popup automatically populates with
Massage
House Painting
Satellite Launching

Then if the user says "No, wait, I was looking for products" and changes the first popup to Products, the second popup clears and populates with
Lawn Mowers
Hedge Trimmers
Laser Cannons

Under this would be a Go button, so if the user chooses Products, then Hedge Trimmers, and clicks Go, he goes to the Hedge Trimmers page.

Any ideas? Is this doable, or should I tell my client to forget it?

I don’t know about the "popup" part, that sounds like it would take some javascript. However, using Wayfinder with its &hideSubMenus parameter will do the trick. You have your top-level menu, and submenus only show when you’ve clicked on one of the top menu level items.

With a bit of javascript, you can make accordions or popups or slide-outs or whatever you want. Wayfinder just generates nested unordered lists, which most of the javascript libraries require.