[NTG-context] How to manually adjust the sort order of items appearing in a custom index?

[Henning Hraban Ramm]

Am 17.01.22 um 16:53 schrieb Joel via ntg-context:
> I created a custom index that displays a list of "Important Dates" 
> appearing in my book. It lists the year, a short description of what 
> happened, and should show the page number.
> 
> I'm running into two errors though:
> 
> First, if the date is the same year, it is sorting alphabetically, 
> example,,,,
> 
> \dateis{1900s+1912}{Yet another event happened}
> \dateis{1900s+1912}{Another event happened}
> 
> ...will print the wrong one first in the index..
> 
> 1912 - Another even happened
> 1912 - Yet another event happened.
> 
> Is there a way to manually tell it to display one first? I don't want to 
> add visible month and day details, that would be even more confusing to 
> the index as I have to print it in American order.
> 
> Second, when it compiles it is not printing the page number, instead 
> prints "[Entry not flushed]".
> 
> -- Joel
> 
> Here is my minimum working example:
> 
> 
> \defineregister[listdates][compress=yes]
> \setupregister[listdates][style=sansbold, textstyle=slanted, n=1, 
> pagenumber=yes]
> 
> \define[2]\dateis{%
>      \listdates{#1~\emdash ~#2}%
> }%
> 
> \starttext
> 
> \dateis{1900s+1911}{Some event happened}
> \dateis{1900s+1912}{Yet another event happened}
> \dateis{1900s+1912}{Another event happened}
> 
> \startchapter[title=Important Dates]
>      \placelistdates
> \stopchapter
> 
> \stoptext

Change your definition of \dateis (or use an additional macro) to use 
the sort key of \index:

\index[1900s+191201]{January}
\index[1900s+191202]{February}

Hraban