Perl Modules and Objects

Standard distribution

• CGI (CGI query object manipulation and methods to create HTML)
• IPC::Open3 (allows forking off of process; used for forking XPat so that the cgi can talk to XPat during its running)
  

Additional Perl modules

• DBI (database interface)
• Apache::Session (used to store data on the server between runs of the CGI)

DLPS related

• Object-Oriented
  • XPat, XPatSearchSet, XPatResult, XPatResultSet
  • XPat
    • encapsulates the cgi’s communication with a running XPat process
    • searches can be individually created and results retrieved OR
    • the queries can be packaged into XPatSearchSet’s and sent as a whole to be run as queries against XPat one after another
    • the results (an XPat set for each query is contained in an XPatResult object) are then packaged into Middleware XPatResultSet which can later be iterated through
  • Bookbag / Portfolio / Personal Collection
    • user can add individual items (bib records, images, books, etc.) into this set of items.
    • In TextClass, can run searches against this set.
  • DlpsSession
    • Since Apache::Session uses Perl tied hashes to access data, and we prefered a more consistent OO approach and syntax, we wrapped the Apache::Session object with our own object. Access to data is therefore the usual Perl Object -> syntax
  • QueryFactory, TerminologyMapper
    • Maps are used to map certain terms to XPat regions (so, for example, the word “title” may map to “region TITLE within ...”.
    • The QueryFactory takes the CGI object and the TermMapper and creates a well-formed XPat query.
    • These are older object modules that could use some rewriting.
  • ProcIns
    • used in conjunction with HTML templates (html files with parts that will be filled in with the running of the cgi)
    • Processing Instructions in the form of <?INSTRUCTION [param=value ...]> can be inserted in HTML. When the cgi program parses the HTML template, the PI will be replaced with some html packaged data or image or...
  • Classes (for now TextClass only, BibClass & ImageClass are not OO yet)
    • Each of the document classes has its own Perl class module that encapsulates much of its information and behavior.
  • PageViewer
    • This object encapsulates the page data in all the PB tags of a page-image based SGML document.
  • WordWheel
    • This object encapsulates a part of the data retrieved during a wordwheel search
  • CollsInfo.pm, GroupsInfo.pm
    • During the beginning of the running of a cgi, info about collections and groups of collections are read into these objects so that it can be easily accessed during the rest of the cgi’s run
• non Object-Oriented
  • DbUtils: various subroutines to handle common DLXS related DBI work
  • DlpsUtils: miscellaneous utility subroutines; e.g., sorting and uniqu-ifying a list, max, min, get list of authorized collections from the environment, etc.
  • DevUtils: routines used only in the development environment
  • TextClassUtils: general routines in TextClass, filtering, building some HTML, etc. (many of the subroutines here will be moved to TextClass and turned into methods)
  • DLPSLocalUtils
  • ICLocalUtils
  • Versioned LibVersion.pm