Sorry to resurrect this old thread, but I'm still not clear on the answer to the question:
In 2014, can a metadata source plugin provide values for custom columns?
I'm working on a plugin and would love to be able to do this.
The "Download metadata fields" section of the "Configure metadata download" window seems to indicate that metadata source plugins can set these custom fields, as my custom fields are listed in that section. But setting the fields in my plugin doesn't seem to work:
Code:
mi = Metadata(title, authors)
# neither of these work
mi.set("#customfield", customvalue)
mi.set("customfield", customvalue)
mi.customfield = customvalue