Hello again,

after fiddling around some more, I stumbled across \getvalue which
seems to solve my problems - for whatever reason ... I guess it does
some preprocessing.

I now got my bibliography enhancements (I needed so far) running. If
someone else needs it, here it is:

\def\mycite{\dodoubleempty\domycite}
\def\defaultciterepeat{Ebenda}
\def\defaultciteprefix{Vgl. }
\def\defaultcitepage{S. }
\def\defaultcitechapter{Kap. }

\def\domycite[#1][#2]{%
  \ifsecondargument
    \getparameters[MCP][prefix=\defaultciteprefix,page=,chapter=,suffix=,#1]
    \doinsertmycite[#2]{\MCPprefix}{%
      \expandoneargafter\doifnotempty{\MCPpage}{\
\defaultcitepage\MCPpage.}%
\expandoneargafter\doifnotempty{\MCPchapter}{\
\defaultcitechapter\MCPchapter.}%
\expandoneargafter\doifnotempty{\MCPsuffix}{\ \MCPsuffix}% } \else
    \doinsertmycite[#1]{\defaultciteprefix}{}
  \fi
}

\def\doinsertmycite[#1]#2#3{%
  \footnote{%
    #2%prefix
    \doifelse{\getvalue{mycitelast}}{#1}%
      {\defaultciterepeat\doifempty{#3}{.}}%
      {\doifelse{\getvalue{mycitepast #1}}{used}%
        {\bgroup%
         \getcitedata[arttitle][#1] to \bibtitle
         \cite[alternative=authoryear][#1]. \bibtitle.%
         \egroup}%
        {\cite[alternative=data][#1]}}%
    #3%suffix
  }
  \setvalue{mycitelast}{#1}
  \setvalue{mycitepast #1}{used}
}

Essentially all it does is: wrap \mycite around \cite to process the
output depending on the circumstances:
  * if the citation is the first of this bib-entry, it is places
    completely into the footnote (alternative=data)
  * if the citation was used before, in the document, it is only
    referenced rather short (author, year, title)
  * if the citation was used _directly_ before, it is not repeated but
    only referenced with the word "Ebenda" (meaning more or less "see
    above")
It is also able to prepend text (like "Vgl. " [="Compare"]) and append
text (like page or chapter number, or a custom string).

Examples:
  \mycite[some_bib_entry]
  \mycite[prefix={Vgl. }, page=123, chapter={Introduction},
  suffix={some more text.}][some_bib_entry]

The only thing it doesn't handle (yet) is, if a citation was
directly used before on a previous page. Then mycitelast should be
reset so that at least the short citation is used. But I wasn't able to
find a safe way to do this. I fiddled around with
\insertpagebreakhandler for a while, but apart from not yielding any
result, I don't believe, that it is intended for stuff like this.

So if someone knows a way to handle that last case (page break) too, I
would be glad to hear about it.

Regards,
Andreas.


On Mon, 29 Jun 2009 21:41:49 +0200
Andreas Schneider <aksdb@gmx.de> wrote:

> Hi,
> 
> I'm currently trying to make a command that outputs different text
> depending on the situation it has been called, but I'm absolutely
> stuck there (I'm not very familiar with TeX, so it's probably obvious
> to most of you :-/). It currently looks like this:
> 
> \doassign[mycite][last=]
> \def\mycite[#1]{%
>   \footnote{%
>      \doifelse{\mycitelast}{#1}{Ebenda}{\cite[alternative=data][#1]}%
>   }
>   \doassign[mycite][last=#1]
> }
> 
> The idea is as follow: if I cite the same citation two or more times
> in a row (e.g. Some text\mycite[chan_genetic_2005] ... more
> text\mycite[chan_genetic_2005]) it should only output the whole
> quotation the first time, and "Ebenda" all the other times. But as it
> seems, the \doifelse always evaluates to false and therefore outputs
> the whole citation every time.
> 
> Does someone see what I might be doing wrong? Or is there even a
> better way to do this?
> 
> Thanks,
> Andreas.
>