Hi Sharon,
The use case is basically a mashup with a collection, and mashups inside that collection with new collections. This involves a service in the top level mashup which returns nested infotables being passed down into the collections. This means some mashups meant to be used in collections have infotables as a mashup parameter.
In one of the mashups I wanted to show/hide something based on the value of a field in one of the infotable parameters, so I created an expression and wanted to pass the field into that expression.
This is a bit of a special situation of course since it relies on the fact that the infotable from which I want to get the field only contains a single row (which it does, because it's a parameter to the service returning the nested structure and it's the selected row from a dropdown). The solution is of course to add the field to the data shape of a higher-level infotable in the nesting structure, adding the value in the service, adding an extra parameter to the mashup and using that.In my use case those are just a bunch of unneeded columns in a datashape and parameters in a mashup.
So:
- user selects row in dropdown
- selected row passed to service
- service returns infotable "resultinfotable", with a column ("selectedrow") of type infotable
- selected row is assigned to selectedrow column.
- infotable is passed to collection, mapping "selectedrow" to a mashup parameter.
- nested mashup needs selectedrow.keyfield in an expression.
I can get to the product.productid from pretty much everywhere I need to, except expressions, and have to add selectedrowkeyfield to the resultinfotable and mashup parameters only to make the expression work.
I think that worked in previous versions and I just wondered why I could bind the column to a bunch of things, but not to an expression (and as it turns out not to another mashup parameter either).
