Re: [NTG-context] Defining command with optional and mandatory arguments

23 May 2018


      On 5/23/2018 3:39 PM, Christoph Reller wrote:
...
Hi,
What is the right way to define a command with both mandatory and
optional arguments, e.g:
\MyCommand[optional][mandatory]
Consider the following MWE:
\unexpanded\def\MyCommand[#1]{
   \dosingleempty{\doMyCommand[#1]}}
\def\doMyCommand[#1][#2]{
   \doifsomething{#1}{number 1: #1\par}
   \doifsomething{#2}{number 2: #2}\blank[big]}
\starttext
\MyCommand[A][B]
\MyCommand[A]
\stoptext
In last year's versions of ConTeXt the output was
number 1: A
number 2: B
number 1: A
In the latest version of ConTeXt the output is
number 1: A
number 2: B
number 2: A
Is this behavior intended? How can I make a definition whose behavior
does not change in new versions of ConTeXt?
i'm not sure wht happens at your end but this is the best way:
\unexpanded\def\MyCommand
   {\dodoubleempty\doMyCommand}

\def\doMyCommand[#1][#2]%
   {\iffirstargument
      number 1: #1%
      \par
    \fi
    \ifsecondargument
      number 2: #2%
    \fi
    \blank[big]}

\starttext
     \MyCommand[A][B]
     \MyCommand[A]
\stoptext


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