When providing custom UI in the ASP report viewer (may also include other viewers) to facilitate the selection of report parameter values, it would be useful to be able to get the available values.  Currently only the definition of available values can be read from a report, there is no mechanism to actually get them without reading that definition and generating your own SQL query etc from the SQLDataSource.

Resolving the values ourselves is dangerous, from a data integrity point of view.  We are re-writing the mechanism to get the values which may not fully reflect the report designer’s intention as we may miss duplicating all of the functionality the report engine does when it processes available values.

The reason why this would be useful is that the current report parameter UI supplied by the viewer is extremely basic and limited.  For example, sometimes we may want to select values from a tree view.  We may wish resolve them through a series of wizard steps.  Either way, being limited to the basic UI doesn’t fit well with individual solutions.

I base this request on the currently available functionality in Microsoft’s reporting service.  This does currently have a function we can call for the reasons described above.