[NTG-context] troubles with \enablemode

[Aditya Mahajan]

On Fri, 30 Oct 2020, Damien Thiriet wrote:

> Hi @list,
> 
> 
> I don't fully understand the \enablemode mechanism. Given this MWE:
> 
> 
> \startmode[test]
> \setupframedtext [foregroundcolor=white,style={\tfa}]
> \stopmode
> 
> 
> \starttext
> \startframedtext
> ceci est un texte
> \stopframedtext
> \enablemode [test]
> \startframedtext
> ceci est un texte
> \stopframedtext
> \stoptext
> 
> I cannot see the expected effect when I compile, that is both texts are
> in black. When I compile with
> context --mode=test 
> both framed texts are in white, which is what I expect.
> 
> What did I miss?

When the compilation starts and context reads the line \startmode[test], the mode is not enabled, so the rest of the block is discarded. When you get to do enable the mode, it is too late. TeX does not do backtracking while compiling a document. Depending on what exactly you want, you could use:

    \startsetups[test]
    ....
    \stopsetups

    ...
    \setups{test}
    ....


Or perhaps even (untested)

    \setupframedtext[foregroundcolor={\doifmode{test}{white}}, style={\tfa}]


Aditya