<?xml version="1.0" encoding="iso-8859-1"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>Module: Publisher</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" /> <meta http-equiv="Content-Script-Type" content="text/javascript" /> <link rel="stylesheet" href=".././rdoc-style.css" type="text/css" media="screen" /> <script type="text/javascript"> // <![CDATA[ function popupCode( url ) { window.open(url, "Code", "resizable=yes,scrollbars=yes,toolbar=no,status=no,height=150,width=400") } function toggleCode( id ) { if ( document.getElementById ) elem = document.getElementById( id ); else if ( document.all ) elem = eval( "document.all." + id ); else return false; elemStyle = elem.style; if ( elemStyle.display != "block" ) { elemStyle.display = "block" } else { elemStyle.display = "none" } return true; } // Make codeblocks hidden by default document.writeln( "<style type=\"text/css\">div.method-source-code { display: none }</style>" ) // ]]> </script> </head> <body> <div id="classHeader"> <table class="header-table"> <tr class="top-aligned-row"> <td><strong>Module</strong></td> <td class="class-name-in-header">Publisher</td> </tr> <tr class="top-aligned-row"> <td><strong>In:</strong></td> <td> <a href="../files/lib/utility/publisher_rb.html"> lib/utility/publisher.rb </a> <br /> </td> </tr> </table> </div> <!-- banner header --> <div id="bodyContent"> <div id="contextContent"> <div id="diagram"> <map id="map" name="map"> <area shape="rect" coords="16,16,109,65" href="Publisher.html" alt="Publisher " /> </map> <img src="../dot/f_57.png" usemap="#map" border="0" alt="dot/f_57.png"> </div> <div id="description"> <p> <a href="Publisher.html">Publisher</a> is a variation on Ruby‘s Observable. We do not keep track of any changed state; instead we assume that by virtue of calling <a href="Publisher.html#M000399">publish</a> we have changed state. We do not allow serialization of subscribers. We allow a <a href="Publisher.html">Publisher</a> to have multiple publications and maintain separate lists of subscribers for each one. </p> </div> </div> <div id="method-list"> <h3 class="section-bar">Methods</h3> <div class="name-list"> <a href="#M000399">publish</a> <a href="#M000395">subscribe</a> <a href="#M000398">subscriber_count</a> <a href="#M000396">unsubscribe</a> <a href="#M000397">unsubscribe_all</a> </div> </div> </div> <!-- if includes --> <div id="section"> <!-- if method_list --> <div id="methods"> <h3 class="section-bar">Public Instance methods</h3> <div id="method-M000399" class="method-detail"> <a name="M000399"></a> <div class="method-heading"> <a href="#M000399" class="method-signature"> <span class="method-name">publish</span><span class="method-args">(*arg)</span> </a> </div> <div class="method-description"> <p> If this object‘s changed state is <tt>true</tt>, invoke the update method in each currently associated subscriber in turn, passing it the given arguments. The changed state is then set to <tt>false</tt>. </p> <p><a class="source-toggle" href="#" onclick="toggleCode('M000399-source');return false;">[Source]</a></p> <div class="method-source-code" id="M000399-source"> <pre> <span class="ruby-comment cmt"># File lib/utility/publisher.rb, line 65</span> <span class="ruby-keyword kw">def</span> <span class="ruby-identifier">publish</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">arg</span>) <span class="ruby-keyword kw">if</span> <span class="ruby-keyword kw">defined?</span> <span class="ruby-ivar">@subscribers</span> <span class="ruby-ivar">@subscribers</span>.<span class="ruby-identifier">dup</span>.<span class="ruby-identifier">each</span> <span class="ruby-keyword kw">do</span> <span class="ruby-operator">|</span><span class="ruby-identifier">s</span><span class="ruby-operator">|</span> <span class="ruby-keyword kw">if</span> <span class="ruby-identifier">s</span>.<span class="ruby-identifier">respond_to?</span>(<span class="ruby-identifier">:to_int</span>) <span class="ruby-constant">Engine</span>.<span class="ruby-identifier">instance</span>.<span class="ruby-identifier">db</span>.<span class="ruby-identifier">get</span>(<span class="ruby-identifier">s</span>).<span class="ruby-identifier">update</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">arg</span>) <span class="ruby-keyword kw">else</span> <span class="ruby-identifier">s</span>.<span class="ruby-identifier">update</span>(<span class="ruby-operator">*</span><span class="ruby-identifier">arg</span>) <span class="ruby-keyword kw">end</span> <span class="ruby-keyword kw">end</span> <span class="ruby-keyword kw">end</span> <span class="ruby-keyword kw">end</span> </pre> </div> </div> </div> <div id="method-M000395" class="method-detail"> <a name="M000395"></a> <div class="method-heading"> <a href="#M000395" class="method-signature"> <span class="method-name">subscribe</span><span class="method-args">(subscriber)</span> </a> </div> <div class="method-description"> <p> Add <tt>subscriber</tt> as an subscriber on this object. <tt>subscriber</tt> will now receive notifications. </p> <p><a class="source-toggle" href="#" onclick="toggleCode('M000395-source');return false;">[Source]</a></p> <div class="method-source-code" id="M000395-source"> <pre> <span class="ruby-comment cmt"># File lib/utility/publisher.rb, line 30</span> <span class="ruby-keyword kw">def</span> <span class="ruby-identifier">subscribe</span>(<span class="ruby-identifier">subscriber</span>) <span class="ruby-ivar">@subscribers</span> <span class="ruby-operator">||=</span> [] <span class="ruby-keyword kw">if</span> <span class="ruby-operator">!</span><span class="ruby-identifier">subscriber</span>.<span class="ruby-identifier">respond_to?</span>(<span class="ruby-identifier">:to_int</span>) <span class="ruby-operator">&&</span> <span class="ruby-operator">!</span><span class="ruby-identifier">subscriber</span>.<span class="ruby-identifier">respond_to?</span>(<span class="ruby-identifier">:update</span>) <span class="ruby-identifier">raise</span> <span class="ruby-constant">NoMethodError</span>, <span class="ruby-value str">"subscriber needs to respond to 'update'"</span> <span class="ruby-keyword kw">end</span> <span class="ruby-ivar">@subscribers</span>.<span class="ruby-identifier">push</span> <span class="ruby-identifier">subscriber</span> <span class="ruby-keyword kw">end</span> </pre> </div> </div> </div> <div id="method-M000398" class="method-detail"> <a name="M000398"></a> <div class="method-heading"> <a href="#M000398" class="method-signature"> <span class="method-name">subscriber_count</span><span class="method-args">()</span> </a> </div> <div class="method-description"> <p> Count of subscribers to this object. </p> <p><a class="source-toggle" href="#" onclick="toggleCode('M000398-source');return false;">[Source]</a></p> <div class="method-source-code" id="M000398-source"> <pre> <span class="ruby-comment cmt"># File lib/utility/publisher.rb, line 56</span> <span class="ruby-keyword kw">def</span> <span class="ruby-identifier">subscriber_count</span> <span class="ruby-ivar">@subscribers</span> <span class="ruby-operator">?</span> <span class="ruby-ivar">@subscribers</span>.<span class="ruby-identifier">size</span> <span class="ruby-operator">:</span> <span class="ruby-value">0</span> <span class="ruby-keyword kw">end</span> </pre> </div> </div> </div> <div id="method-M000396" class="method-detail"> <a name="M000396"></a> <div class="method-heading"> <a href="#M000396" class="method-signature"> <span class="method-name">unsubscribe</span><span class="method-args">(subscriber)</span> </a> </div> <div class="method-description"> <p> Delete <tt>subscriber</tt> as a subscriber on this object. It will no longer receive notifications. </p> <p><a class="source-toggle" href="#" onclick="toggleCode('M000396-source');return false;">[Source]</a></p> <div class="method-source-code" id="M000396-source"> <pre> <span class="ruby-comment cmt"># File lib/utility/publisher.rb, line 42</span> <span class="ruby-keyword kw">def</span> <span class="ruby-identifier">unsubscribe</span>(<span class="ruby-identifier">subscriber</span>) <span class="ruby-ivar">@subscribers</span>.<span class="ruby-identifier">delete</span> <span class="ruby-identifier">subscriber</span> <span class="ruby-keyword kw">if</span> <span class="ruby-keyword kw">defined?</span> <span class="ruby-ivar">@subscribers</span> <span class="ruby-keyword kw">end</span> </pre> </div> </div> </div> <div id="method-M000397" class="method-detail"> <a name="M000397"></a> <div class="method-heading"> <a href="#M000397" class="method-signature"> <span class="method-name">unsubscribe_all</span><span class="method-args">()</span> </a> </div> <div class="method-description"> <p> Delete all subscribers associated with this object. </p> <p><a class="source-toggle" href="#" onclick="toggleCode('M000397-source');return false;">[Source]</a></p> <div class="method-source-code" id="M000397-source"> <pre> <span class="ruby-comment cmt"># File lib/utility/publisher.rb, line 49</span> <span class="ruby-keyword kw">def</span> <span class="ruby-identifier">unsubscribe_all</span> <span class="ruby-ivar">@subscribers</span>.<span class="ruby-identifier">clear</span> <span class="ruby-keyword kw">if</span> <span class="ruby-keyword kw">defined?</span> <span class="ruby-ivar">@subscribers</span> <span class="ruby-keyword kw">end</span> </pre> </div> </div> </div> </div> </div> <div id="validator-badges"> <p><small><a href="http://validator.w3.org/check/referer">[Validate]</a></small></p> </div> </body> </html>