WorkspaceGroup pointer cannot be used as input to an algorithm

[Martyn Gigg]

Basically this means that you can't use a pointer to a WorkspaceGroup in a child algorithms the WorkspaceProperty won't accept it.

Sample code that won't work:

    Mantid::API::FrameworkManager::Instance().exec("Load", 4, "Filename", "CSP79590.raw", "OutputWorkspace", "test_ws");

    auto ws = Mantid::API::AnalysisDataService::Instance().retrieveWS<Mantid::API::Workspace>("test_ws");

    Mantid::API::IAlgorithm * alg = Mantid::API::FrameworkManager::Instance().createAlgorithm("Scale");
    alg->initialize();
    alg->setChild(true);
    alg->setProperty("InputWorkspace",ws);
    alg->setPropertyValue("OutputWorkspace","__anonymous");
    alg->execute();

The problem lies with the WorkspaceProperty around these lines (253-261):

            try 
            {
              wksp = AnalysisDataService::Instance().retrieve(m_workspaceName);
            }
            catch( Kernel::Exception::NotFoundError &)
            {
              // Check to see if the workspace is not logged with the ADS because it is optional.
              return isOptionalWs();
            }

They correctly check for a group but the only way to satisfy the property is to have a string value, which it won't have if its been set by pointer.

[Nick Draper]

Moved to r2.6 at the end of r2.5

[Martyn Gigg]

Batch move to 2.7

[Russell Taylor]

I came across this while looking at #8226 and really not liking the specific rather than general solution implemented there.

It seems like what we need to do here is somehow enable the WorkspaceProperty to hold the value as a base class pointer. I guess this is either by changing the type of PropertyWithValue::m_value (very tricky) or by adding a member (which then leads to holding the value in two places and having to keep them synchronized).

[Nick Draper]

Bulk move to assigned at the introduction of the triage step

[Nick Draper]

Moved to the backlog at the code freeze of R3.3

[Stuart Campbell]

This ticket has been transferred to github issue ​7103