Hello,

First of all, I am working from a Standard Edition, and there is no sensitive information in this thread.

I am trying to copy data from a data page to a property. I am referring to this section from a Pega article:

"Optional data mapping on the property form – On the Edit Property form, the Optional Data Mapping field appears when you select Copy data from a data page. Use this data transform to copy a subset of the data from the data page to the property. If you do not specify a data transform, the system copies all of the data from the data page to the property."
https://docs-previous.pega.com/application-development/87/data-transforms

I created a data page D_PageToMapPropertyFromDTUn which uses a data transform to get the page AccessGroup (Data-Admin-Operator-AccessGroup) to its Primary property (so it will copy the whole page). I created a property MapPropertyFromDTDeux of type Single Page, set its data access to 'Copy data from a data page,' and set the data page to D_PageToMapPropertyFromDTUn. I created a test case type, then I updated the pySetFieldDefaults data transform of the case type as follows:
Update page .MapPropertyFromDTDeux
    Set Param.void = "Param.void"

I assumed that I did not have to map any property since it should be done by the 'Copy data from a data page' option, and there would be no purpose in setting that data access if I had to map the property anyway.

When running the case type, the page D_PageToMapPropertyFromDTUn is properly set identically to the AccessGroup page, but the property MapPropertyFromDTDeux is blank; it only contains the pxObjClass property.

I would like to know why it did not work as I expected. Did I misunderstand the purpose of the 'Copy data from a data page' data access?