Beefy Boxes and Bandwidth Generously Provided by pair Networks
Keep It Simple, Stupid
 
PerlMonks  

Comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
How does one debug a Perl program containing multiple subroutines that generate HTML pages that use Javascript on the Web (and uses SQL to pull data from the database)?

If you're very lucky, he used some sort of HTML templating module. (HTML::Template is probably the easiest to get started with.) That can help immensely because it avoids having oodles of print statements spewing out HTML code at numerous places in your code.

Unfortunately, I suspect you aren't that lucky.

If you're lucky, the 8,000 line file is done as a separate module (something.pm), with just a short perl program calling the initial subroutine in that module. If that's the case, it's easy to write short perl programs of your own to call subroutines in that module to test things out. For example, if there is a subroutine in the module that accepts an employee name as a parameter and returns that employee's salary, you can easily write a short perl program to call that subroutine, pass it a hard-coded name for testing purposes, and then print out the salary that is returned on the command line. That allows you to debug just that tiny segment of code from the command line, rather than dealing with the entire CGI environment in a web browser.

Unfortunately, I suspect you aren't that lucky in this bit, either.

If the changes you will be making are quite minor, I would recommend making the changes first and verifying that they work before doing any significant structural work.

If the changes are going to be extensive, then I would suggest restructuring the existing code first to make it easier to make the future changes.

Suggested modules: CGI.pm, DBI.pm, HTML::Template, Config::IniFiles, Test::More, HTML::FillInForm, CGI::Application, CGI::Application::ValidateRM. These let you easily read data from a form (via CGI.pm), read from the database (via DBI.pm), display values in an HTML page (via HTML::Template), read from a configuration file (Config::IniFiles), run automated tests to ensure that a routine that you had working earlier hasn't been broken by later changes (Test::More), pre-populate a web form (HTML::FillInForm), handle CGI interactions via run-modes (CGI::Application), and validate data entered in a form (CGI::Application::ValidateRM).

An 8,000 line program without "use warnings" and "use strict" that incorporates HTML, JavaScript, and SQL without modules and automated tests is pretty much a textbook example of what NOT to drop on someone who is new to Perl.

Look on the bright side -- every Perl project you have after this one will be easier! :-)

Wally Hartshorn

(Plug: Visit JavaJunkies, PerlMonks for Java)


In reply to Re: Sub-initiate needs help getting started by Wally Hartshorn
in thread Sub-initiate needs help getting started by Lori713

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the monastery is silent...

    How do I use this? | Other CB clients
    Other Users?
    Others having an uproarious good time at the Monastery: (7)
    As of 2018-06-21 14:18 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?
      Should cpanminus be part of the standard Perl release?



      Results (118 votes). Check out past polls.

      Notices?