Two improvement requests for the new bibliography subsystem:

1. Tag titles (and subtitles) with the language explicitly provided in the bib entry.
2. Add editor and translator to fields supported in \cite[field][tag].

An example follows. It shows that the title generated by the \cite[title][tag] does not have an associated language, even though the bib entry specifies one and the publications manual indicates that this is intended for the rendering and hyphenation of the title. It is apparently used for that in the bibliography, but it is needed as well in the text. (And yes, Formenwandlungen does have the same hyphenation points in both German and English; this was just a convenient example.)

It also shows that [translator] is not inserted into the text.

NOTE that when \cite[editor][tag] is attempted (and present in the bib entry) compilation halts with the Lua error  no string to print, but continues to completion when allowed.

 \mainlanguage[en]

 \startbuffer[TestBib]
    @BOOK{Tschichold1953,
      author       = {Jan Tschichold},
      title        = {Formenwandlungen der \&-Zeichen},
      year         = {1953},
      publisher    = {D. Stempelag},
      address      = {Frankfurt am Main},
      language     = {german},
    }
    @BOOK{Plaat1957,
      author       = {Jan Tschichold},
      translator   = {Frederick Plaat},
      title        = {The Ampersand: Its origin and development},
      year         = {1957},
      publisher    = {Woudhuysen},
      address      = {London},
      note         = {Translation by F.\ Plaat of \cite{Tschichold1953}.},
    }
 \stopbuffer
 
 \loadbtxdefinitionfile[apa]
 \usebtxdataset        [TestBib]
                       [TestBib.buffer]
 \definebtxrendering   [TestBib]
                       [apa]
                       [dataset=TestBib]

 \setupspellchecking   [state=start,
                        method=3]
 \definecolor          [word:de]
                       [r=.85]

 \starttext
     \startparagraph
         \cite[title][TestBib::Plaat1957]
         is a translation by \cite[translator][TestBib::Plaat1957]
         of \cite[title][TestBib::Tschichold1953]
         by \cite[author][TestBib::Tschichold1953].
     \stopparagraph
     \startparagraph
         {\it The Ampersand: Its origin and development}
         is a translation by Frederick Plaat
         of {\it\de Formenwandlungen der \&-Zeichen}
         by Jan Tschichold.
     \stopparagraph
     \blank[big]

     \placebtxrendering[TestBib][method=dataset]
 \stoptext

Rik