[log4perl-devel] Fwd: RE: Log::Log4perl::Layout::PatternLayout

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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">Hi Mike,</span></font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003"></span></font><font face="Arial,sans-serif"  size="2">&nbsp;</font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">Thank you for your quick response.</span></font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003"></span></font><font face="Arial,sans-serif"  size="2">&nbsp;</font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">Yes, you could send out the qns on the
list, that will be very helpful.</span></font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003"></span></font><font face="Arial,sans-serif"  size="2">&nbsp;</font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">Sorry I should have explained in more
detail. Here it goes:</span></font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003"></span></font><font face="Arial,sans-serif"  size="2">&nbsp;</font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">We have two levels of sub classing - <font  color="#000000">A.pm</font> is a subclass of
Log::Log4perl::Layout::PatternLayout and in this module we have
specified&nbsp;different layouts we need to work with. These layouts include
%d, %F, %L, %M and many other&nbsp;placeholders and are used for all&nbsp;our
logs and&nbsp;<font color="#000000">A.pm</font> has been doing just fine for
almost a year now.</span></font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003"></span></font><font face="Arial,sans-serif"  size="2">&nbsp;</font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">This is the first time we are creating logs
from the Database and we want to leverage the code in <font  color="#000000">A.pm</font>, so we thought of creating a subclass of&nbsp;<font  color="#000000">A.pm</font> named <font color="#000000">B.pm</font>&nbsp;where
we could</span></font><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">&nbsp;use the same layouts but </span></font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003"></span></font><font face="Arial,sans-serif"  size="2">&nbsp;</font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">
<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">1.&nbsp;pass&nbsp;the&nbsp;%d placeholder&nbsp;the time from
the database instead of the default&nbsp;current_time it picks up.</span></font></div>
<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003"></span></font>&nbsp;</div>
</span></font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">2. pass '' for %F %L %M and other
placeholders we&nbsp;do not have information for in the database. </span></font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003"></span></font><font face="Arial,sans-serif"  size="2">&nbsp;</font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">
<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">3. pass a constant value to&nbsp;MDC only for
the set of logs from the database.</span></font></div>
<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003"></span></font>&nbsp;</div>
</span></font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">Unfortunately the only way we thought we
could accomplish that was by overriding&nbsp;what gets passed to these
placeholders <font color="#000000">current_time()</font> for %d, <font  color="#000000">curly_action()</font> for %X{progname} and <font  color="#000000">render()</font>&nbsp;for other placeholders, in this new
Module.</span></font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003"></span></font><font face="Arial,sans-serif"  size="2">&nbsp;</font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">So when our program runs it&nbsp;creates two
sets of logs, one set using <font color="#000000">A.pm </font>with
all %d %F %L placeholders populated correctly and the other set using <font  color="#000000">B.pm</font> for logs from the database.</span></font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003"></span></font><font face="Arial"  color="#0000ff" size="2"><span class="505504314-03122003"></span></font><font  face="Arial" color="#0000ff" size="2"><span class="505504314-03122003"></span></font><font  face="Arial,sans-serif" size="2">&nbsp;</font></div>
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<div><font face="Arial" color="#0000ff" size="2"><span  class="505504314-03122003">Any suggestions on how else we could
accomplish the same will be very welcome.</span></font></div>
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<div><font face="Arial,sans-serif" size="2">&nbsp;</font></div>
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<div align="left"><font face="Arial" color="#0000ff" size="2">Thank you,</font></div>
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<div align="left"><font face="Arial" color="#0000ff" size="2">Armaity</font></div>
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<blockquote><font face="Arial,sans-serif"  size="2"> </font><font face="Arial,sans-serif" size="2"> </font>
  <div class="OutlookMessageHeader" lang="en-us" dir="ltr" align="left"><font  face="Tahoma" size="2">-----Original Message-----<br>
  <b>From:</b> Mike Schilli [<a class="moz-txt-link-freetext" href="mailto:msc...@ao...">mailto:msc...@ao...</a>] <br>
  <b>Sent:</b> Tuesday, December 02, 2003 10:19 PM<br>
  <b>To:</b> Armaity.Bilimoria<br>
  <b>Cc:</b> <a class="moz-txt-link-abbreviated" href="mailto:m...@pe...">m...@pe...</a><br>
  <b>Subject:</b> Re: Log::Log4perl::Layout::PatternLayout<br>
  <br>
  </font></div>
  <font face="Arial,sans-serif" size="2"><font size="2"><span  type="cite">Armaity.Bilimoria wrote on 12/2/2003, 8:36 AM:</span> </font>
  </font><font face="Arial,sans-serif" size="2"> </font>
  <blockquote type="cite"><font face="Arial,sans-serif" size="2"> </font>
    <div><font face="Arial,sans-serif" size="2"><span  class="012060216-02122003">
    <div><span class="786062115-02122003"><font face="Arial"><font  size="2"><span class="012060216-02122003">1. pass the date that was
stored in the database instead of the letting it pick up the default
current_time.&nbsp;We had to overload <font color="#0000ff">current_time()</font></span></font></font></span></div>
    </span></font></div>
  </blockquote>
  <font size="2" face="Arial,sans-serif"><font face="Arial,sans-serif">Hi
  </font></font><font face="Arial,sans-serif" size="2"><font size="2"><span  type="cite">Armaity,</span><br>
  <br>
  </font></font><font size="2" face="Arial,sans-serif"><font  face="Arial,sans-serif">I've added changes (scheduled for 0.41)
that'll let you pass in an optional array to the PatternLayout
constructor, enabling you to specify your own timing function:<br>
  <br>
&nbsp;&nbsp;&nbsp; my $layout = Log::Log4perl::Layout::PatternLayout-&gt;new( {
time_function =&gt; \&amp; my_time_function }, "%m%n" );<br>
  <br>
Will this work for you?<br>
  </font></font><font face="Arial,sans-serif" size="2"> </font>
  <blockquote type="cite"><font face="Arial,sans-serif" size="2"> </font>
    <div><font face="Arial,sans-serif" size="2"><span  class="012060216-02122003">
    <div><span class="786062115-02122003"><font face="Arial" size="2"><span  class="012060216-02122003">2.&nbsp;we do not&nbsp;have&nbsp;information in the
database table regarding the filename, line number, the pid, the
method&nbsp;where the logging request was issue, etc., and so had to
subclass <font color="#0000ff">render()</font> to make sure those
values were set to '' and not pass information about the perl daemon
doing the transfer.</span></font></span></div>
    </span></font></div>
  </blockquote>
  <font size="2" face="Arial,sans-serif"><font face="Arial,sans-serif">Hmm
... why aren't you just specifying a layout format that doesn't have
%F, %L, etc. placeholders but constants?</font></font><font  face="Arial,sans-serif" size="2"><br>
  </font>
  <blockquote type="cite"><font face="Arial,sans-serif" size="2"> </font>
    <div><font face="Arial,sans-serif" size="2"><span  class="012060216-02122003">
    <div><span class="786062115-02122003"><font face="Arial"><font  size="2"><span class="012060216-02122003">3. we need to also override <font  color="#0000ff">curly_action()</font>&nbsp;to assign a constant value to <font  size="3"><font size="2">%X{progname}, used in our layout, </font></font>and
set other options to ''.</span></font></font></span></div>
    </span></font></div>
  </blockquote>
  <font size="2" face="Arial,sans-serif"><font face="Arial,sans-serif">Wouldn't
setting the MDC get you the desired result?</font></font><font  face="Arial,sans-serif" size="2"><br>
  </font>
  <blockquote type="cite"><font face="Arial,sans-serif" size="2"> </font>
    <div><font face="Arial,sans-serif" size="2"><span  class="012060216-02122003">
    <div><span class="786062115-02122003"><font face="Arial"><font  size="2"><span class="012060216-02122003"></span></font></font></span><span  class="786062115-02122003"><font size="+0"><span  class="012060216-02122003"></span><font face="Arial"><font size="2"><span  class="012060216-02122003">We are now faced with&nbsp;the </span>difficult<span  class="012060216-02122003">y&nbsp;that</span>&nbsp;subclassing&nbsp;<span  class="012060216-02122003">provide</span><span  class="012060216-02122003">s, constant comparison required&nbsp;<span  class="012060216-02122003">by&nbsp;our team&nbsp;</span>for future releases of
this Module and possible changes in our code to support newer releases.</span></font></font></font></span></div>
    </span></font></div>
  </blockquote>
  <font size="2" face="Arial,sans-serif"><font face="Arial,sans-serif">It's
unlikely that we're gonna change these parts, but you're certainly
correct, overriding non-public methods is a gamble :).</font></font><font  face="Arial,sans-serif" size="2"><br>
  </font><font size="2" face="Arial,sans-serif"><font face="Arial"><br>
Let me know what you think of my comments above, we'll see what we can
do to accomodate your needs. <br>
  <br>
Is it ok with you if I forward your question to the mailing list?
Chances are someone else will find it helpful.<br>
  <br>
  </font></font><font face="Arial,sans-serif" size="2"><font size="2"><span  id="x-photon-sig-17303305">-- <br>
-- Mike<br>
Mike Schilli<br>
  <a class="moz-txt-link-abbreviated" href="mailto:m...@pe...">m...@pe...</a></span></font>
  </font></blockquote>
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