# [NTG-context] Modes and conditional part of the source

Thu Feb 28 12:54:06 CET 2019

On Thu, 28 Feb 2019, Procházka Lukáš Ing. wrote:

> Hello,
>
> I'm struggling with using modes to make a part of the text conditional.
>
> Here is my code:
>
> ----
> \def\b#1{\startmode[#1]}
> \def\e{\stopmode}
>
> % \enablemode[100] % For optional usage
>
> \starttext
> A
> \b{100} % Should be start of some conditional text from here ...
>   B
> \e % ... to here
> \stoptext

Modes don't work that way. You can do something like this:

\define[1]\bbb
{\doifnotmode{#1}
{\grabbufferdata[dummy][bbb][eee]}}

\let\eee\relax

\enablemode[100]

\starttext
A

\bbb{100}
Inside mode 100
\eee

\bbb{101}
Inside mode 101
\eee

\stoptext

Depending on the actual use case, there might be simpler ways.