The preview of a document (or url) is determined by the first eligable column in a table. When there are multiple columns in a table that could provide a preview, it is not possible to specify which of those columns to use. A possible work-a-round is to create multiple views were for each view the relevant column is the first one. This however is not an optimal solution because the end-user would have to switch tabs to navigate to the specific view with only a subset of the data.
In our situation we work with different renditions of the same document which can have different storage locations and with that different column types. Although every rendition is a separat record, the different storage types are available in the same record and only the first will be used for the preview. The list of documents can contain documents from different storage locations where only the first technical column shows the preview.
My proposal is to, in stead of the technical location, use the definition of a subject (or derived variant) as the base to determine which column to use for the preview. This could then be the first visibile column where a variant or layout procedure would determine the visibility of the column to view. This could mean that when there are two eligable columns in a subject, if the first is made hidden, the second column would be used for the preview.
