I noticed an interesting problem today when using the out of the box connection/filtering capabilities of list web parts.
First I created two lists. One contains a list of training materials and the other comments regarding specific items in the training list. I place these both on a web part page in their list web part forms and select the relevant views. I then configured a connection such that a selected training item filters the comments list web part to show only those comments associated with the selected training item. On the training list I am using a view that groups the training materials by role and then category. Using the grouping function I am able to drill down through all 900 odd items in the list even though SharePoint has a default limit of 100 items configured behind the screens.
When you select a training item that is within the first 100 on the list the filter function works beautifully. The problem occurs when you select a training item above the first 100. When you do this it seems that even though you can see the item on the grouped view the connection between the two web parts can’t and hence the filter stops working, in fact the filter seems to disappear completely and you are presented with all comments on all training items.
So then, how do we fix it. The answer is fairly simplistic. Modify the view and set the number of items displayed to some arbitrary number that is large enough that the problem shouldn’t be an issue. In my case I set it to 1000 as it is unlikely for a while to come that the list of training items will exceed this.
By the way I also discovered that the SharePoint List Filter Web Part also has a limit of 100 items but decided I didn’t need to use this as the web part connection filtering approach was more suitable for my requirements.