The last aspect is displaying either the summary or line item data. In fact all portal lines include both data but using some conditional formatting we can hide or display data based on the underlying type of the record. At the simplest level the portals have the ‘details’ displayed under the summary fields. The summary fields are in fact calcs defined to evaluate to empty unless the are a sub-summary or grand-summary.
The conditional formatting on the fields is simply:
The fields are set to transparent as default so usually the underlying data is visible. So with no data to display and the type not setting the conditional formatting to grey for line items the line items are visible, flag a row as a sub-summary or grand total and the formatting kicks in, hides the underlying fields. The calculation fields now return values which display.