Showing Categorized Views in Web Applications

Categorized views are kind of a trademark of Lotus Notes (Client) applications. We like them, we build them, we love them. We also want to see them on the web. There is only one small issue: That display of information is pretty unique to Notes. You do find this tree/table combination in other applications only to display files (like Nautilus, Finder or KDE) but not data. So a categorized view is kind of odd on the web. I played around to find alternate displays for single and multiple category data. Here is what I came up with.

• Single Category view with Listbox
  The category isn't part of the view itself but a picklist on the left (which might be filled by a @DbColumn). The table shows the current selection matching the selection. Works out of the box already today. Interesting extension challenge: allow selection of multiple entries in the listbox.
  
• Single Category view with Combobox
  A variation of the first theme. Useful if you have a lot of view columns and need the real estate on the left. Variation: Instead of the dropdown: show a link that uses a popup to allow selection of the category to show.
  
• Multiple Categories with Combobox
  This actually works also with a sorted view since the limit key takes an array as entry. As variation similar to the previous example could be to show a breadcrumb link list that allow to click or hover to show the selection. Challenge: How to make it obvious that you need to select/narrow from left to right. Extra challenge: when you change box 2 and the value in box 3 is no longer an available value
  
• Multiple Categories in tree/table combination
  Looks like a file dialogue, so users should be familiar. You trade horizontal space for vertical space. Makes navigation in categories more accessible since all categories are available any time
  
• Pivot view on 3 categories
  Category 2 becomes the columns of the table, Category 3 the rows. Adds sums to rows and columns. Good base material for graphs. Challenge: decide on the aggregation mode: sum/average/percentage -or- optional display of such a column
  
• Pivot view on 3 categories with data rows
  Similar concept like the previous but with individual data rows displayed. Might show additional aggregation rows or columns
  

Now someone needs to build all these custom controls. All the images have been build using Balsamip Mockups