Updating List based on portal filtering and using results in conditional format
I have a portal with a list of companies, sorted alphabetically by name. I use some conditional formatting to show a single letter at the top and to the left of each letter group (e.g. an "A" at the first company that begins with "A", a "B" at the first company that begins with "B", etc.). I want to have each of these letter sections alternate between two colors, so that all the "A's" have the first color, all the "B's" have the second color, etc. I tried using a conditional calc like this:
// when true, it changes the fill color
This works great…unless there are no companies that begin with a certain letter. In that case, I get two consecutive sections with the same color. I realize I need to do something like create a list which is a summary of all the first letters used and then replace my formula with one that looks at the number where the letter occurs in that list, but am unsure of how to best go about this. And, to make things even tricker, this needs to update based on the filtering of the list at any given time, meaning the value list would need to update based on the current portal filtering. Any ideas?
UPDATE: I'm now able to create a list that does not include missing first letters using a custom function from Brian Dunning's site (Value_Dedupe, http://www.briandunning.com/cf/1109 ). Still having trouble filtering it so it matches the filtered portal set.