\label{Authoring_Scripting_Tags}

\begin{itemize}
\item \textbf{display}\index{display}: The intervening Perl script is evaluated
in the safe space and the return value of the script replaces the
entire tag.
\item \textbf{import}\index{import}: This causes the parse to read in the file
named in the body of the tag and parse it as if the entire text of
the file had existed at the location of the tag.
\item \textbf{parserlib}\index{parserlib}: The enclosed filename contains
definitions for new tags.
\item \textbf{script}\index{script}: If the attribute \textbf{type} is
set to {}``loncapa/perl'' the enclosed data is a Perl script which
is evaluated inside the Perl safe space. The return value of the script
is ignored. 
\item \textbf{scriptlib}\index{scriptlib}: The enclosed filename contains
Perl code to run in the safe space.
\item \textbf{block}\index{block}: This has a required argument \textbf{condition}
that is evaluated. If the condition is true, everything inside the
tag is evaluated; otherwise, everything inside the block tag is skipped.
\item \textbf{notsolved}\index{notsolved}: Everything inside the tag is
skipped if the problem is {}``solved''.
\item \textbf{postanswerdate}\index{postanswerdate}: Everything inside
the tag is skipped if the problem is before the answer date.
\item \textbf{preduedate}\index{preduedate}: Everything inside the tag
is skipped if the problem is after the due date. 
\item \textbf{randomlist}\index{randomlist}: The enclosed tags are parsed
in a stable random order. The optional attribute \textbf{show} restricts
the number of tags inside that are actually parsed to no more than
\textbf{show}.
\item \textbf{solved}\index{solved}: Everything inside the tag is skipped
if the problem is {}``not solved''.
\item \textbf{while}\index{while}: This implements a while loop. The required
attribute \textbf{condition} is a Perl scriptlet that when evaluated
results in a true or false value. If true, the entirety of the text
between the whiles is parsed. The condition is tested again, etc.
If false, it goes to the next tag.
\end{itemize}