Re: [NTG-context] Title for tabulate

14 Dec 2021

      On 12/14/2021 6:16 PM, Benjamin Buchmuller via ntg-context wrote:
...
Hi!
I'd like to follow up on a problem that Denis came across recently with the titles argument in tabulate. (It's more a solution than a question, but any hints to improve the answer are welcome.) I wanted to use this argument for an easy specification of, well, a title for a "recipe". The advantage is that all information is held together and it's easy to use for people who are not (too) familiar with ConTeXt.
So, in one file I can define all styles (which the end-user would not need to see):
\definetabulate[recipe][|l|l|p|l|]
\setuptabulate
  [recipe]
  [
  bodyfont=small,
  distance=medium,
  before={\blank[back, small]},
  header=text,
  headstyle=\bi, % this formats the "\BC" cells
  headcolor=red, % this formats the "\BC" cells
  ]
\starttext
And then use:
\startrecipe[title={Whatever mixture 1}]
\FL
\NC Absolute \BC Stock \NC Ingredient \NC Final \NR
\HL
\NC 1 \NR
\LL
\stoprecipe
\startrecipe[title={Whatever mixture 2}]
\FL
\BC Absolute \BC Stock \BC Ingredient \BC Final \NR
\HL
\NC 1 \NR
\LL
\stoprecipe
\stoptext
etc.
However, I cannot change the way the title is styled (or spaced from the table) unless I do "title={\bi Some text.}". However, blank commands are also stripped off at this place. (I also don't get a clue from the source if there is any argument to spike-in some formatting.)
So, if there is no easy way to access this one, we can work around:
\definetabulate[recipetab][|l|l|p|l|]
\setuptabulate
  [recipetab]
  [
  bodyfont=small,
  distance=medium,
  before={\blank[back, small]},
  % header=text, % THIS MUST NOT BE "text"
  headstyle=bold,
  headcolor=red,
  ]
\define\startrecipe{\dodoubleempty\dostartrecipe}
\long\def\dostartrecipe[#1][#2]#3\stoprecipe{%
  \iffirstargument
      {\bi #1}\blank[medium]
  \fi
  \ifsecondargument
      \startrecipetab[#2]
      #3
      \stoprecipetab
  \else
      \startrecipetab
      #3
      \stoprecipetab
  \fi
}
\startrecipe[Head 1]
\FL
\BC Absolute \BC Stock \BC Ingredient \BC Final \NR
\HL
\NC 1 \NR
\LL
\stoprecipe
\startrecipe[Head 2][headcolor=blue] % pass on arguments to tabulate
\FL
\BC Absolute \BC Stock \BC Ingredient \BC Final \NR
\HL
\NC 1 \NR
\LL
\stoprecipe
Small question though: Is there a ConTeXt way to "\long\def" or a simple way ("user interface") to filter a list of arguments for a specific key=val pair, e.g. to make a single optional argument with headertitle={Some header.}?
context has no (need for) \long ... all is long (i mever saw a reason 
for using it)
(1) use a proper head:

\definehead[RecipeHead][subsubsubsubsubsubject]
\setuphead [RecipeHead][style=bolditalic,after={\blank[medium]}]

\definetabulate[recipetab][|l|l|p|l|]

\setuptabulate
   [recipetab]
   [bodyfont=small,
    distance=medium,
    before={\blank[back, small]},
    headstyle=bold,
    headcolor=red]

here's a one-step lmtx solution:

\let\stoprecipe\relax

\tolerant\protected\def\startrecipe[#1]#*[#2]#3\stoprecipe
   {\ifcstok{#1}\emptytoks\else
      \RecipeHead{#1}
    \fi
    \ifcstok{#2}\emptytoks
      \startrecipetab#3\stoprecipetab
    \else
      \startrecipetab[#2]#3\stoprecipetab
    \fi}

or just

\tolerant\protected\def\startrecipe[#1]#*[#2]#3\stoprecipe
   {\ifempty{#1}\else
      \RecipeHead{#1}
    \fi
    \ifempty{#2}%
      \startrecipetab#3\stoprecipetab
    \else
      \startrecipetab[#2]#3\stoprecipetab
    \fi}

and here's one that does what you ask (in the core i'd try to avoid 
grabbing too much arguments and if real core we'd make sure dummy 
parameters don;t interfere):

\tolerant\protected\def\startrecipe[#1]#2\stoprecipe
   {\ifempty{#1}%
      \startrecipetab#2\stoprecipetab
    \orelse\ifhastok={#1}%
      \getdummyparameters[headtitle=,#1]
      \ifempty{\dummyparameter{headtitle}}\else
        \normalexpanded{\RecipeHead{\dummyparameter{headtitle}}}
      \fi
      \startrecipetab[#1]#2\stoprecipetab
    \else
      \RecipeHead{#1}
      \startrecipetab#2\stoprecipetab
    \fi}

\startrecipe[headtitle={Head 3},headcolor=blue] % pass on arguments to 
tabulate
\FL
\BC Absolute \BC Stock \BC Ingredient \BC Final \NR
\HL
\NC 1 \NR
\LL
\stoprecipe

Here's a variant:

\def\theparameter#1#2%
   {\beginlocalcontrol
    \begingroup
    \getdummyparameters[#1=,#2]%
    \normalexpanded{\endgroup\endlocalcontrol\dummyparameter{#1}}}

\tolerant\protected\def\startrecipe[#1]#2\stoprecipe
   {\ifempty{#1}%
      \startrecipetab#2\stoprecipetab
    \orelse\ifhastok={#1}%
      \edef\MyHeadTitle{\theparameter{headtitle}{#1}}%
      \ifempty\MyHeadTitle\else
        \normalexpanded{\RecipeHead{\MyHeadTitle}}
      \fi
      \startrecipetab[#1]#2\stoprecipetab
    \else
      \RecipeHead{#1}
      \startrecipetab#2\stoprecipetab
    \fi}

or just

\tolerant\protected\def\startrecipe[#1]#2\stoprecipe
   {\ifempty{#1}%
      \startrecipetab#2\stoprecipetab
    \else
      \edef\MyHeadTitle{\theparameter{headtitle}{#1}}%
      \ifempty\MyHeadTitle\else
        \normalexpanded{\RecipeHead{\MyHeadTitle}}
      \fi
      \startrecipetab[#1]#2\stoprecipetab
    \fi}

or

\tolerant\protected\def\startrecipe[#1]#2\stoprecipe
   {\ifempty{#1}%
      \startrecipetab#2\stoprecipetab
    \else
      \ifcstok{\theparameter{headtitle}{#1}}\emptytoks\else
        \normalexpanded{\RecipeHead{\theparameter{headtitle}{#1}}}
      \fi
      \startrecipetab[#1]#2\stoprecipetab
    \fi}

or ... or ... or ...

just play with it a bit till you have something that looks nice in code too

Hans

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