\label{Institutional_Integration_Course_Codes}
Courses in a domain can be self-cataloging if assigned an institutional
code. For this to work two routines need to be customized in localenroll.pm
- \emph{instcode\_format()} and \emph{instcode\_defaults()}. The first
of these is used to split institutional course codes into their constituent
parts, and populate some perl data structures with these data, which
LON-CAPA can use to generate linked select boxes which users can use
to create filters to apply when searching the {}``official'' course
catalog. The second routine constructs a regular expression used when
searching for courses based on the filter chosen by the user, which
will contain fragments of an institutional code. 

\textbf{\large instcode\_format} 

Six arguments are required:

\begin{enumerate}
\item domain (\$dom)
\item reference to hash of institutional course IDs (\$instcodes)
\item reference to hash of codes (\$codes)
\item reference to array of titles (\$codetitles), e.g., @\{\$codetitles\}
= (\char`\"{}year\char`\"{},\char`\"{}semester\char`\"{},\char`\"{}department\char`\"{},\char`\"{}number\char`\"{})
\item reference to hash of abbreviations used in categories, (\$cat\_titles)
e.g., 

\begin{quote}
\%\{\$\$cat\_titles\{'Semester'\}\} = (
\begin{quote}
fs => 'Fall',

ss => 'Spring',

us => 'Summer');
\end{quote}
\end{quote}
\item reference to hash of arrays specifying sort order used in category
titles (\$cat\_order), e.g., @\{\$\$cat\_order\{'Semester'\}\} = ('ss','us','fs'); 
\end{enumerate}
The routine returns 'ok' if no errors occurred.

At MSU, {}``fs03nop590,'' is an example of an institutional course
code; including the following entry in the instcodes hash passed in
by reference - \$\$instcodes\{'43551dedcd43febmsul1'\} = 'fs03nop590'
would cause the \$codes perl data structure to be populated.

fs03nop590 would be split as follows:

\$\$codes\{\{'year'\} = '2003'

\$\$codes\{'semester'\} = 'Fall'

\$\$codes\{'department'\} = 'nop'

\$\$codes\{'number'\} = '590'

The routine used at MSU is as follows:

\begin{quotation}
\texttt{sub instcode\_format \{}
\begin{quotation}
\texttt{my (\$dom,\$instcodes,\$codes,\$codetitles,\$cat\_titles,\$cat\_order)
= @\_;}

\texttt{@\{\$codetitles\} = (\char`\"{}Year\char`\"{},\char`\"{}Semester\char`\"{},\char`\"{}Department\char`\"{},\char`\"{}Number\char`\"{});}

\texttt{\%\{\$\$cat\_titles\{'Semester'\}\} = (}
\begin{quotation}
\texttt{fs => 'Fall',}

\texttt{ss => 'Spring',}

\texttt{us => 'Summer'}
\end{quotation}
\texttt{);}

\texttt{@\{\$\$cat\_order\{'Semester'\}\} = ('ss','us','fs');}

\texttt{foreach my \$cid (keys \%\{\$instcodes\}) \{}
\begin{quotation}
\texttt{if (\$\$instcodes\{\$cid\} =\~{} m/\^{}({[}suf]s)(\textbackslash{}d\{2\})(\textbackslash{}w\{2,3\})(\textbackslash{}d\{3,4\}\textbackslash{}w?)\$/)
\{}
\begin{quotation}
\texttt{\$\$codes\{\$cid\}\{'Semester'\} = \$1;}

\texttt{\$\$codes\{\$cid\}\{'Department'\} = \$3;}

\texttt{\$\$codes\{\$cid\}\{'Number'\} = \$4;}

\texttt{my \$year = \$2;}

\texttt{my \$numyear = \$year;}

\texttt{\$numyear =\~{} s/\^{}0//;}

\texttt{\$\$codes\{\$cid\}\{'Year'\} = \$year;}

\texttt{unless (defined(\$\$cat\_titles\{'Year'\}\{\$year\})) \{}
\begin{quotation}
\texttt{\$\$cat\_titles\{'Year'\}\{\$year\} = 2000 + \$numyear;}
\end{quotation}
\texttt{\}}
\end{quotation}
\texttt{\}}
\end{quotation}
\texttt{\}}

\texttt{my \$outcome = 'ok';}

\texttt{return \$outcome;}
\end{quotation}
\texttt{\}}
\end{quotation}
\textbf{\large instcode\_defaults}{\large \par}

Three arguments are required:

\begin{enumerate}
\item domain (\$dom)
\item reference to hash which will contain default regular expression matches
for different components of an institutional course code


(\$defaults)

\item reference to array which will contain order of component parts used
in institutional code. (\$code\_order)
\end{enumerate}
The routine returns 'ok' if no errors occurred.

At MSU, the regular expression fragments used mirror those included
in the regular expression used in instcode\_format() to split an institutional
course code into its component parts.

\begin{quotation}
\texttt{sub instcode\_defaults \{}
\begin{quotation}
\texttt{my (\$dom,\$defaults,\$code\_order) = @\_;}

\texttt{\%\{\$defaults\} = (}
\begin{quotation}
\texttt{'Year' => '\textbackslash{}d\{2\}',}

\texttt{'Semester' => '\^{}{[}sfu]s',}

\texttt{'Department' => '\textbackslash{}w\{2,3\}',}

\texttt{'Number' => '\textbackslash{}d\{3,4\}\textbackslash{}w?',}
\end{quotation}
\texttt{);}

\texttt{@\{\$code\_order\} = ('Semester','Year','Department','Number');}

\texttt{return 'ok';}
\end{quotation}
\texttt{\}}
\end{quotation}