Deliantra MORPG

Last change: 2007-10-15

PA^pp

Advantages and Disadvantages of using PA^pp

Please see also the document I wrote for one of my presentations about PApp, which enumerates the most important features quite nicely.

Advantages

• Speed. PA^pp isn't much slower than a hand-coded mod_perl handler, and this is only due to the extra database request to fetch and restore state, which typically you would do anyway. To the contrary: a non-trivial Apache::Registry page is much slower than the equivalent PA^pp application (or much, much more complicated)
• Embedded Perl. You can freely embed perl into your documents. In fact, You can do things like these:

     <h1>Names and amounts</h1>
     <:
        my $st = sql_exec "select name, amount from ...",
                 [\my($name, $amount];
  
        while ($st->fetch) ?>
           Name: $name, Amount: $amount<p>
        <:
     :>
     <hr>
  

  That is, mixing html and perl at statement boundaries. )
• State-preserving: The global hash %S is automaticaly preserved during the session. Everything you save there will be available in any subsequent pages that the user accesses.
• XML. PA^pp-applications are written in XML. While this is no advantage in itself
• Easy internationalization. I18n has never been that easy: just mark you strings with __"string", either in html or in the perl source. The "poedit"-demo-application enables editing of the strings on-line, so translaters need not touch any text files and can work diretcly via the web.
• Feature-Rich. PA^pp comes with a lot of small-but-nice-to-have functionality.

Disadvantages

• Perl5.7-DEVEL is required. Randal Schwartz asked me to provide some explanation on why this is so (back then only 5.6 was required, but 5.6.0 is waaay to buggy):

  "As for an explanation, I require perl5.6 because I require a whole lot of features of 5.6 (e.g. DB.pm, utf-8 support, "our", bugfixes, 3-argument open, regex improvements, probably many others, especially changes on the XS level). In the future it will likely require weak references, filehandle autovivification, the XSLoader for extra speed in rare circumstances... I don't want to backport this to older versions ;)"

Documentation

• An introduction to the features of PApp (with little code examples)
• Ein Tutorial (auf Deutsch)

Manpages

• PApp, the main module.
• PApp::SQL, easy and fast SQL support.
• PApp::XML, xml templates and more.
• PApp::XSLT, xslt stylesheet processing.
• PApp::Env, communicate between processes and the outside.
• PApp::HTML, badly-written HTML support macros.
• PApp::FormBuffer, multipart/form streaming buffer.
• PApp::Exception, exception handling.
• PApp::Callback, a workaround for the problem of nonserializable code.
• PApp::Application, implements the PApp::Application class.
• PApp::Package, implements namespaces and submodules.
• PApp::Parser, papp-file parser and compiler.
• PApp::Config, holds PApp configuration parameters.
• PApp::Recode, character set conversion.
• PApp::User, manipulate user/groups.
• PApp::Util, various utility-junk.
• PApp::Lock, persistant, breakable, verbose locks.
• PApp::I18n, implements the internationalization support.
• PApp::Apache, glue module for mod_perl operation.
• PApp::Admin, common administrative tasks.
• PApp::PCode, intermediate embedded perl representation.
• PApp::CGI, unfinished glue module for standalone CGI operation.
• PApp::Log, logfile analyzing and state cache cleanup.
• macro/admin, user access utilities for PApp.
• macro/util, some utility functions.
• macro/editform, macros used for creating sql editing forms.
• bin/papp-env, utility to set/clear/display/list papp environment variables.
• bin/papp-admin, administrate PApp from the commandline.
• bin/papp-httpd, simple webserver to get started quickly.

Availability

Among other things, you need perl-devel.

Changes

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Any questions/hints/critics? Contact the author of this page!