
<div class='fossil-doc' data-title='tcl::transform::observe - Reflected/virtual channel support'>
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<div class="doctools">
<h1 class="doctools_title">tcl::transform::observe(n) 1 tcllib &quot;Reflected/virtual channel support&quot;</h1>
<div id="name" class="doctools_section"><h2><a name="name">Name</a></h2>
<p>tcl::transform::observe - Observer transformation, stream copy</p>
</div>
<div id="toc" class="doctools_section"><h2><a name="toc">Table Of Contents</a></h2>
<ul class="doctools_toc">
<li class="doctools_section"><a href="#toc">Table Of Contents</a></li>
<li class="doctools_section"><a href="#synopsis">Synopsis</a></li>
<li class="doctools_section"><a href="#section1">Description</a></li>
<li class="doctools_section"><a href="#section2">API</a></li>
<li class="doctools_section"><a href="#section3">Bugs, Ideas, Feedback</a></li>
<li class="doctools_section"><a href="#keywords">Keywords</a></li>
<li class="doctools_section"><a href="#category">Category</a></li>
<li class="doctools_section"><a href="#copyright">Copyright</a></li>
</ul>
</div>
<div id="synopsis" class="doctools_section"><h2><a name="synopsis">Synopsis</a></h2>
<div class="doctools_synopsis">
<ul class="doctools_requirements">
<li>package require <b class="pkgname">Tcl 8.6</b></li>
<li>package require <b class="pkgname">tcl::transform::core <span class="opt">?1?</span></b></li>
<li>package require <b class="pkgname">tcl::transform::observe <span class="opt">?1?</span></b></li>
</ul>
<ul class="doctools_syntax">
<li><a href="#1"><b class="cmd">::tcl::transform::observe</b> <i class="arg">chan</i> <i class="arg">logw</i> <i class="arg">logr</i></a></li>
</ul>
</div>
</div>
<div id="section1" class="doctools_section"><h2><a name="section1">Description</a></h2>
<p>The <b class="package">tcl::transform::observer</b> package provides a command
creating a channel transformation which passes the read and written
bytes through unchanged (like <b class="package"><a href="identity.html">tcl::transform::identity</a></b>), but
additionally copies the data it has seen for each direction into
channels specified at construction time.</p>
<p>Related transformations in this module are
<b class="package"><a href="adler32.html">tcl::transform::adler32</a></b>,
<b class="package"><a href="vt_counter.html">tcl::transform::counter</a></b>,
<b class="package"><a href="vt_crc32.html">tcl::transform::crc32</a></b>, and
<b class="package"><a href="identity.html">tcl::transform::identity</a></b>.</p>
<p>The internal <b class="package"><a href="../../../../index.html#key756">TclOO</a></b> class implementing the transform
handler is a sub-class of the <b class="package"><a href="../virtchannel_core/transformcore.html">tcl::transform::core</a></b>
framework.</p>
</div>
<div id="section2" class="doctools_section"><h2><a name="section2">API</a></h2>
<dl class="doctools_definitions">
<dt><a name="1"><b class="cmd">::tcl::transform::observe</b> <i class="arg">chan</i> <i class="arg">logw</i> <i class="arg">logr</i></a></dt>
<dd><p>This command creates an observer transformation on top of the channel
<i class="arg">chan</i> and returns its handle. The channel handles <i class="arg">logr</i> and
<i class="arg">logw</i> are there the data is copied to.</p></dd>
</dl>
</div>
<div id="section3" class="doctools_section"><h2><a name="section3">Bugs, Ideas, Feedback</a></h2>
<p>This document, and the package it describes, will undoubtedly contain
bugs and other problems.
Please report such in the category <em>virtchannel</em> of the
<a href="http://core.tcl.tk/tcllib/reportlist">Tcllib Trackers</a>.
Please also report any ideas for enhancements you may have for either
package and/or documentation.</p>
</div>
<div id="keywords" class="doctools_section"><h2><a name="keywords">Keywords</a></h2>
<p><a href="../../../../index.html#key277">channel transformation</a>, <a href="../../../../index.html#key649">observer</a>, <a href="../../../../index.html#key47">reflected channel</a>, <a href="../../../../index.html#key650">stream copy</a>, <a href="../../../../index.html#key278">tip 230</a>, <a href="../../../../index.html#key279">transformation</a>, <a href="../../../../index.html#key44">virtual channel</a></p>
</div>
<div id="category" class="doctools_section"><h2><a name="category">Category</a></h2>
<p>Channels</p>
</div>
<div id="copyright" class="doctools_section"><h2><a name="copyright">Copyright</a></h2>
<p>Copyright &copy; 2009 Andreas Kupries &lt;andreas_kupries@users.sourceforge.net&gt;</p>
</div>
</div>
