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<title>Twisted Documentation: The Evolution of Finger: moving to a component based architecture</title>
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<link href="../stylesheet.css" rel="stylesheet" type="text/css"/>
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<h1 class="title">The Evolution of Finger: moving to a component based architecture</h1>
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<div class="toc"><ol><li><a href="#auto0">Introduction</a></li><li><a href="#auto1">Write Maintainable Code</a></li><li><a href="#auto2">Advantages of Latest Version</a></li><li><a href="#auto3">Aspect-Oriented Programming</a></li></ol></div>
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<h2>Introduction<a name="auto0"/></h2>
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<p> This is the fourth part of the Twisted tutorial <a href="index.html" shape="rect">Twisted from Scratch, or The Evolution of Finger</a>.</p>
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<p>In this section of the tutorial, we'll move our code to a component
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architecture so that adding new features is trivial.
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See <a href="../components.html" shape="rect">Interfaces and Adapters</a> for a more
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complete discussion of components.</p>
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<h2>Write Maintainable Code<a name="auto1"/></h2>
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<p>In the last version, the service class was three times longer than
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any other class, and was hard to understand. This was because it turned
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out to have multiple responsibilities. It had to know how to access
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user information, by rereading the file every half minute,
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but also how to display itself in a myriad of protocols. Here, we
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used the component-based architecture that Twisted provides to achieve
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a separation of concerns. All the service is responsible for, now,
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is supporting getUser/getUsers. It declares its support via a call to
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zope.interface.implements. Then, adapters are used to make this service
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look like an appropriate class for various things: for supplying
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a finger factory to TCPServer, for supplying a resource to site's
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constructor, and to provide an IRC client factory for TCPClient.
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All the adapters use are the methods in FingerService they are
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declared to use: getUser/getUsers. We could, of course,
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skip the interfaces and let the configuration code use
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things like FingerFactoryFromService(f) directly. However, using
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interfaces provides the same flexibility inheritance gives: future
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subclasses can override the adapters.</p>
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<div class="py-listing"><pre><p class="py-linenumber"> 1
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</p><span class="py-src-comment"># Do everything properly, and componentize</span>
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<span class="py-src-keyword">from</span> <span class="py-src-variable">twisted</span>.<span class="py-src-variable">application</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">internet</span>, <span class="py-src-variable">service</span>
285
<span class="py-src-keyword">from</span> <span class="py-src-variable">twisted</span>.<span class="py-src-variable">internet</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">protocol</span>, <span class="py-src-variable">reactor</span>, <span class="py-src-variable">defer</span>
286
<span class="py-src-keyword">from</span> <span class="py-src-variable">twisted</span>.<span class="py-src-variable">words</span>.<span class="py-src-variable">protocols</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">irc</span>
287
<span class="py-src-keyword">from</span> <span class="py-src-variable">twisted</span>.<span class="py-src-variable">protocols</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">basic</span>
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<span class="py-src-keyword">from</span> <span class="py-src-variable">twisted</span>.<span class="py-src-variable">python</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">components</span>
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<span class="py-src-keyword">from</span> <span class="py-src-variable">twisted</span>.<span class="py-src-variable">web</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">resource</span>, <span class="py-src-variable">server</span>, <span class="py-src-variable">static</span>, <span class="py-src-variable">xmlrpc</span>
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<span class="py-src-keyword">from</span> <span class="py-src-variable">zope</span>.<span class="py-src-variable">interface</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">Interface</span>, <span class="py-src-variable">implements</span>
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<span class="py-src-keyword">import</span> <span class="py-src-variable">cgi</span>
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<span class="py-src-keyword">class</span> <span class="py-src-identifier">IFingerService</span>(<span class="py-src-parameter">Interface</span>):
295
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">user</span>):
296
<span class="py-src-string">"""Return a deferred returning a string"""</span>
298
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUsers</span>():
299
<span class="py-src-string">"""Return a deferred returning a list of strings"""</span>
301
<span class="py-src-keyword">class</span> <span class="py-src-identifier">IFingerSetterService</span>(<span class="py-src-parameter">Interface</span>):
303
<span class="py-src-keyword">def</span> <span class="py-src-identifier">setUser</span>(<span class="py-src-parameter">user</span>, <span class="py-src-parameter">status</span>):
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<span class="py-src-string">"""Set the user's status to something"""</span>
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">catchError</span>(<span class="py-src-parameter">err</span>):
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<span class="py-src-keyword">return</span> <span class="py-src-string">"Internal error in server"</span>
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<span class="py-src-keyword">class</span> <span class="py-src-identifier">FingerProtocol</span>(<span class="py-src-parameter">basic</span>.<span class="py-src-parameter">LineReceiver</span>):
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">lineReceived</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>):
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<span class="py-src-variable">d</span> = <span class="py-src-variable">self</span>.<span class="py-src-variable">factory</span>.<span class="py-src-variable">getUser</span>(<span class="py-src-variable">user</span>)
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<span class="py-src-variable">d</span>.<span class="py-src-variable">addErrback</span>(<span class="py-src-variable">catchError</span>)
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">writeValue</span>(<span class="py-src-parameter">value</span>):
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<span class="py-src-variable">self</span>.<span class="py-src-variable">transport</span>.<span class="py-src-variable">write</span>(<span class="py-src-variable">value</span>+<span class="py-src-string">'\r\n'</span>)
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<span class="py-src-variable">self</span>.<span class="py-src-variable">transport</span>.<span class="py-src-variable">loseConnection</span>()
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<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-variable">writeValue</span>)
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<span class="py-src-keyword">class</span> <span class="py-src-identifier">IFingerFactory</span>(<span class="py-src-parameter">Interface</span>):
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">user</span>):
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<span class="py-src-string">"""Return a deferred returning a string"""</span>
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">buildProtocol</span>(<span class="py-src-parameter">addr</span>):
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<span class="py-src-string">"""Return a protocol returning a string"""</span>
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<span class="py-src-keyword">class</span> <span class="py-src-identifier">FingerFactoryFromService</span>(<span class="py-src-parameter">protocol</span>.<span class="py-src-parameter">ServerFactory</span>):
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<span class="py-src-variable">implements</span>(<span class="py-src-variable">IFingerFactory</span>)
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<span class="py-src-variable">protocol</span> = <span class="py-src-variable">FingerProtocol</span>
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">service</span>):
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<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span> = <span class="py-src-variable">service</span>
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>):
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<span class="py-src-keyword">return</span> <span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>.<span class="py-src-variable">getUser</span>(<span class="py-src-variable">user</span>)
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<span class="py-src-variable">components</span>.<span class="py-src-variable">registerAdapter</span>(<span class="py-src-variable">FingerFactoryFromService</span>,
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<span class="py-src-variable">IFingerService</span>,
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<span class="py-src-variable">IFingerFactory</span>)
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<span class="py-src-keyword">class</span> <span class="py-src-identifier">FingerSetterProtocol</span>(<span class="py-src-parameter">basic</span>.<span class="py-src-parameter">LineReceiver</span>):
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">connectionMade</span>(<span class="py-src-parameter">self</span>):
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<span class="py-src-variable">self</span>.<span class="py-src-variable">lines</span> = []
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">lineReceived</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">line</span>):
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<span class="py-src-variable">self</span>.<span class="py-src-variable">lines</span>.<span class="py-src-variable">append</span>(<span class="py-src-variable">line</span>)
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">connectionLost</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">reason</span>):
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<span class="py-src-keyword">if</span> <span class="py-src-variable">len</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">lines</span>) == <span class="py-src-number">2</span>:
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<span class="py-src-variable">self</span>.<span class="py-src-variable">factory</span>.<span class="py-src-variable">setUser</span>(*<span class="py-src-variable">self</span>.<span class="py-src-variable">lines</span>)
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<span class="py-src-keyword">class</span> <span class="py-src-identifier">IFingerSetterFactory</span>(<span class="py-src-parameter">Interface</span>):
360
<span class="py-src-keyword">def</span> <span class="py-src-identifier">setUser</span>(<span class="py-src-parameter">user</span>, <span class="py-src-parameter">status</span>):
361
<span class="py-src-string">"""Return a deferred returning a string"""</span>
363
<span class="py-src-keyword">def</span> <span class="py-src-identifier">buildProtocol</span>(<span class="py-src-parameter">addr</span>):
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<span class="py-src-string">"""Return a protocol returning a string"""</span>
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<span class="py-src-keyword">class</span> <span class="py-src-identifier">FingerSetterFactoryFromService</span>(<span class="py-src-parameter">protocol</span>.<span class="py-src-parameter">ServerFactory</span>):
369
<span class="py-src-variable">implements</span>(<span class="py-src-variable">IFingerSetterFactory</span>)
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<span class="py-src-variable">protocol</span> = <span class="py-src-variable">FingerSetterProtocol</span>
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">service</span>):
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<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span> = <span class="py-src-variable">service</span>
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">setUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>, <span class="py-src-parameter">status</span>):
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<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>.<span class="py-src-variable">setUser</span>(<span class="py-src-variable">user</span>, <span class="py-src-variable">status</span>)
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<span class="py-src-variable">components</span>.<span class="py-src-variable">registerAdapter</span>(<span class="py-src-variable">FingerSetterFactoryFromService</span>,
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<span class="py-src-variable">IFingerSetterService</span>,
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<span class="py-src-variable">IFingerSetterFactory</span>)
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<span class="py-src-keyword">class</span> <span class="py-src-identifier">IRCReplyBot</span>(<span class="py-src-parameter">irc</span>.<span class="py-src-parameter">IRCClient</span>):
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">connectionMade</span>(<span class="py-src-parameter">self</span>):
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<span class="py-src-variable">self</span>.<span class="py-src-variable">nickname</span> = <span class="py-src-variable">self</span>.<span class="py-src-variable">factory</span>.<span class="py-src-variable">nickname</span>
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<span class="py-src-variable">irc</span>.<span class="py-src-variable">IRCClient</span>.<span class="py-src-variable">connectionMade</span>(<span class="py-src-variable">self</span>)
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">privmsg</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>, <span class="py-src-parameter">channel</span>, <span class="py-src-parameter">msg</span>):
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<span class="py-src-variable">user</span> = <span class="py-src-variable">user</span>.<span class="py-src-variable">split</span>(<span class="py-src-string">'!'</span>)[<span class="py-src-number">0</span>]
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<span class="py-src-keyword">if</span> <span class="py-src-variable">self</span>.<span class="py-src-variable">nickname</span>.<span class="py-src-variable">lower</span>() == <span class="py-src-variable">channel</span>.<span class="py-src-variable">lower</span>():
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<span class="py-src-variable">d</span> = <span class="py-src-variable">self</span>.<span class="py-src-variable">factory</span>.<span class="py-src-variable">getUser</span>(<span class="py-src-variable">msg</span>)
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<span class="py-src-variable">d</span>.<span class="py-src-variable">addErrback</span>(<span class="py-src-variable">catchError</span>)
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<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-keyword">lambda</span> <span class="py-src-variable">m</span>: <span class="py-src-string">"Status of %s: %s"</span> % (<span class="py-src-variable">msg</span>, <span class="py-src-variable">m</span>))
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<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-keyword">lambda</span> <span class="py-src-variable">m</span>: <span class="py-src-variable">self</span>.<span class="py-src-variable">msg</span>(<span class="py-src-variable">user</span>, <span class="py-src-variable">m</span>))
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<span class="py-src-keyword">class</span> <span class="py-src-identifier">IIRCClientFactory</span>(<span class="py-src-parameter">Interface</span>):
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<span class="py-src-string">"""
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"""</span>
405
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">user</span>):
406
<span class="py-src-string">"""Return a deferred returning a string"""</span>
408
<span class="py-src-keyword">def</span> <span class="py-src-identifier">buildProtocol</span>(<span class="py-src-parameter">addr</span>):
409
<span class="py-src-string">"""Return a protocol"""</span>
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<span class="py-src-keyword">class</span> <span class="py-src-identifier">IRCClientFactoryFromService</span>(<span class="py-src-parameter">protocol</span>.<span class="py-src-parameter">ClientFactory</span>):
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<span class="py-src-variable">implements</span>(<span class="py-src-variable">IIRCClientFactory</span>)
416
<span class="py-src-variable">protocol</span> = <span class="py-src-variable">IRCReplyBot</span>
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<span class="py-src-variable">nickname</span> = <span class="py-src-variable">None</span>
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">service</span>):
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<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span> = <span class="py-src-variable">service</span>
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<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>):
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<span class="py-src-keyword">return</span> <span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>.<span class="py-src-variable">getUser</span>(<span class="py-src-variable">user</span>)
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<span class="py-src-variable">components</span>.<span class="py-src-variable">registerAdapter</span>(<span class="py-src-variable">IRCClientFactoryFromService</span>,
426
<span class="py-src-variable">IFingerService</span>,
427
<span class="py-src-variable">IIRCClientFactory</span>)
429
<span class="py-src-keyword">class</span> <span class="py-src-identifier">UserStatusTree</span>(<span class="py-src-parameter">resource</span>.<span class="py-src-parameter">Resource</span>):
431
<span class="py-src-variable">implements</span>(<span class="py-src-variable">resource</span>.<span class="py-src-variable">IResource</span>)
433
<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">service</span>):
434
<span class="py-src-variable">resource</span>.<span class="py-src-variable">Resource</span>.<span class="py-src-variable">__init__</span>(<span class="py-src-variable">self</span>)
435
<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span> = <span class="py-src-variable">service</span>
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<span class="py-src-variable">self</span>.<span class="py-src-variable">putChild</span>(<span class="py-src-string">'RPC2'</span>, <span class="py-src-variable">UserStatusXR</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>))
438
<span class="py-src-keyword">def</span> <span class="py-src-identifier">render_GET</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">request</span>):
439
<span class="py-src-variable">d</span> = <span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>.<span class="py-src-variable">getUsers</span>()
440
<span class="py-src-keyword">def</span> <span class="py-src-identifier">formatUsers</span>(<span class="py-src-parameter">users</span>):
441
<span class="py-src-variable">l</span> = [<span class="py-src-string">'<li><a href="%s">%s</a></li>'</span> % (<span class="py-src-variable">user</span>, <span class="py-src-variable">user</span>)
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<span class="py-src-keyword">for</span> <span class="py-src-variable">user</span> <span class="py-src-keyword">in</span> <span class="py-src-variable">users</span>]
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<span class="py-src-keyword">return</span> <span class="py-src-string">'<ul>'</span>+<span class="py-src-string">''</span>.<span class="py-src-variable">join</span>(<span class="py-src-variable">l</span>)+<span class="py-src-string">'</ul>'</span>
444
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-variable">formatUsers</span>)
445
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-variable">request</span>.<span class="py-src-variable">write</span>)
446
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-keyword">lambda</span> <span class="py-src-variable">_</span>: <span class="py-src-variable">request</span>.<span class="py-src-variable">finish</span>())
447
<span class="py-src-keyword">return</span> <span class="py-src-variable">server</span>.<span class="py-src-variable">NOT_DONE_YET</span>
449
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getChild</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">path</span>, <span class="py-src-parameter">request</span>):
450
<span class="py-src-keyword">if</span> <span class="py-src-variable">path</span>==<span class="py-src-string">""</span>:
451
<span class="py-src-keyword">return</span> <span class="py-src-variable">UserStatusTree</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>)
452
<span class="py-src-keyword">else</span>:
453
<span class="py-src-keyword">return</span> <span class="py-src-variable">UserStatus</span>(<span class="py-src-variable">path</span>, <span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>)
455
<span class="py-src-variable">components</span>.<span class="py-src-variable">registerAdapter</span>(<span class="py-src-variable">UserStatusTree</span>, <span class="py-src-variable">IFingerService</span>,
456
<span class="py-src-variable">resource</span>.<span class="py-src-variable">IResource</span>)
458
<span class="py-src-keyword">class</span> <span class="py-src-identifier">UserStatus</span>(<span class="py-src-parameter">resource</span>.<span class="py-src-parameter">Resource</span>):
460
<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>, <span class="py-src-parameter">service</span>):
461
<span class="py-src-variable">resource</span>.<span class="py-src-variable">Resource</span>.<span class="py-src-variable">__init__</span>(<span class="py-src-variable">self</span>)
462
<span class="py-src-variable">self</span>.<span class="py-src-variable">user</span> = <span class="py-src-variable">user</span>
463
<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span> = <span class="py-src-variable">service</span>
465
<span class="py-src-keyword">def</span> <span class="py-src-identifier">render_GET</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">request</span>):
466
<span class="py-src-variable">d</span> = <span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>.<span class="py-src-variable">getUser</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">user</span>)
467
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-variable">cgi</span>.<span class="py-src-variable">escape</span>)
468
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-keyword">lambda</span> <span class="py-src-variable">m</span>:
469
<span class="py-src-string">'<h1>%s</h1>'</span>%<span class="py-src-variable">self</span>.<span class="py-src-variable">user</span>+<span class="py-src-string">'<p>%s</p>'</span>%<span class="py-src-variable">m</span>)
470
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-variable">request</span>.<span class="py-src-variable">write</span>)
471
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-keyword">lambda</span> <span class="py-src-variable">_</span>: <span class="py-src-variable">request</span>.<span class="py-src-variable">finish</span>())
472
<span class="py-src-keyword">return</span> <span class="py-src-variable">server</span>.<span class="py-src-variable">NOT_DONE_YET</span>
475
<span class="py-src-keyword">class</span> <span class="py-src-identifier">UserStatusXR</span>(<span class="py-src-parameter">xmlrpc</span>.<span class="py-src-parameter">XMLRPC</span>):
477
<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">service</span>):
478
<span class="py-src-variable">xmlrpc</span>.<span class="py-src-variable">XMLRPC</span>.<span class="py-src-variable">__init__</span>(<span class="py-src-variable">self</span>)
479
<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span> = <span class="py-src-variable">service</span>
481
<span class="py-src-keyword">def</span> <span class="py-src-identifier">xmlrpc_getUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>):
482
<span class="py-src-keyword">return</span> <span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>.<span class="py-src-variable">getUser</span>(<span class="py-src-variable">user</span>)
485
<span class="py-src-keyword">class</span> <span class="py-src-identifier">FingerService</span>(<span class="py-src-parameter">service</span>.<span class="py-src-parameter">Service</span>):
487
<span class="py-src-variable">implements</span>(<span class="py-src-variable">IFingerService</span>)
489
<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">filename</span>):
490
<span class="py-src-variable">self</span>.<span class="py-src-variable">filename</span> = <span class="py-src-variable">filename</span>
491
<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span> = {}
492
<span class="py-src-variable">self</span>.<span class="py-src-variable">_read</span>()
494
<span class="py-src-keyword">def</span> <span class="py-src-identifier">_read</span>(<span class="py-src-parameter">self</span>):
495
<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span>.<span class="py-src-variable">clear</span>()
496
<span class="py-src-keyword">for</span> <span class="py-src-variable">line</span> <span class="py-src-keyword">in</span> <span class="py-src-variable">file</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">filename</span>):
497
<span class="py-src-variable">user</span>, <span class="py-src-variable">status</span> = <span class="py-src-variable">line</span>.<span class="py-src-variable">split</span>(<span class="py-src-string">':'</span>, <span class="py-src-number">1</span>)
498
<span class="py-src-variable">user</span> = <span class="py-src-variable">user</span>.<span class="py-src-variable">strip</span>()
499
<span class="py-src-variable">status</span> = <span class="py-src-variable">status</span>.<span class="py-src-variable">strip</span>()
500
<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span>[<span class="py-src-variable">user</span>] = <span class="py-src-variable">status</span>
501
<span class="py-src-variable">self</span>.<span class="py-src-variable">call</span> = <span class="py-src-variable">reactor</span>.<span class="py-src-variable">callLater</span>(<span class="py-src-number">30</span>, <span class="py-src-variable">self</span>.<span class="py-src-variable">_read</span>)
503
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>):
504
<span class="py-src-keyword">return</span> <span class="py-src-variable">defer</span>.<span class="py-src-variable">succeed</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span>.<span class="py-src-variable">get</span>(<span class="py-src-variable">user</span>, <span class="py-src-string">"No such user"</span>))
506
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUsers</span>(<span class="py-src-parameter">self</span>):
507
<span class="py-src-keyword">return</span> <span class="py-src-variable">defer</span>.<span class="py-src-variable">succeed</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span>.<span class="py-src-variable">keys</span>())
510
<span class="py-src-variable">application</span> = <span class="py-src-variable">service</span>.<span class="py-src-variable">Application</span>(<span class="py-src-string">'finger'</span>, <span class="py-src-variable">uid</span>=<span class="py-src-number">1</span>, <span class="py-src-variable">gid</span>=<span class="py-src-number">1</span>)
511
<span class="py-src-variable">f</span> = <span class="py-src-variable">FingerService</span>(<span class="py-src-string">'/etc/users'</span>)
512
<span class="py-src-variable">serviceCollection</span> = <span class="py-src-variable">service</span>.<span class="py-src-variable">IServiceCollection</span>(<span class="py-src-variable">application</span>)
513
<span class="py-src-variable">internet</span>.<span class="py-src-variable">TCPServer</span>(<span class="py-src-number">79</span>, <span class="py-src-variable">IFingerFactory</span>(<span class="py-src-variable">f</span>)
514
).<span class="py-src-variable">setServiceParent</span>(<span class="py-src-variable">serviceCollection</span>)
515
<span class="py-src-variable">internet</span>.<span class="py-src-variable">TCPServer</span>(<span class="py-src-number">8000</span>, <span class="py-src-variable">server</span>.<span class="py-src-variable">Site</span>(<span class="py-src-variable">resource</span>.<span class="py-src-variable">IResource</span>(<span class="py-src-variable">f</span>))
516
).<span class="py-src-variable">setServiceParent</span>(<span class="py-src-variable">serviceCollection</span>)
517
<span class="py-src-variable">i</span> = <span class="py-src-variable">IIRCClientFactory</span>(<span class="py-src-variable">f</span>)
518
<span class="py-src-variable">i</span>.<span class="py-src-variable">nickname</span> = <span class="py-src-string">'fingerbot'</span>
519
<span class="py-src-variable">internet</span>.<span class="py-src-variable">TCPClient</span>(<span class="py-src-string">'irc.freenode.org'</span>, <span class="py-src-number">6667</span>, <span class="py-src-variable">i</span>
520
).<span class="py-src-variable">setServiceParent</span>(<span class="py-src-variable">serviceCollection</span>)
521
</pre><div class="caption">Source listing - <a href="listings/finger/finger19.tac"><span class="filename">listings/finger/finger19.tac</span></a></div></div>
523
<h2>Advantages of Latest Version<a name="auto2"/></h2>
526
<li>Readable -- each class is short</li>
527
<li>Maintainable -- each class knows only about interfaces</li>
528
<li>Dependencies between code parts are minimized</li>
529
<li>Example: writing a new IFingerService is easy</li>
531
<div class="py-listing"><pre><p class="py-linenumber"> 1
560
</p><span class="py-src-keyword">class</span> <span class="py-src-identifier">IFingerSetterService</span>(<span class="py-src-parameter">Interface</span>):
562
<span class="py-src-keyword">def</span> <span class="py-src-identifier">setUser</span>(<span class="py-src-parameter">user</span>, <span class="py-src-parameter">status</span>):
563
<span class="py-src-string">"""Set the user's status to something"""</span>
565
<span class="py-src-comment"># Advantages of latest version</span>
567
<span class="py-src-keyword">class</span> <span class="py-src-identifier">MemoryFingerService</span>(<span class="py-src-parameter">service</span>.<span class="py-src-parameter">Service</span>):
569
<span class="py-src-variable">implements</span>([<span class="py-src-variable">IFingerService</span>, <span class="py-src-variable">IFingerSetterService</span>])
571
<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, **<span class="py-src-parameter">kwargs</span>):
572
<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span> = <span class="py-src-variable">kwargs</span>
574
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>):
575
<span class="py-src-keyword">return</span> <span class="py-src-variable">defer</span>.<span class="py-src-variable">succeed</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span>.<span class="py-src-variable">get</span>(<span class="py-src-variable">user</span>, <span class="py-src-string">"No such user"</span>))
577
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUsers</span>(<span class="py-src-parameter">self</span>):
578
<span class="py-src-keyword">return</span> <span class="py-src-variable">defer</span>.<span class="py-src-variable">succeed</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span>.<span class="py-src-variable">keys</span>())
580
<span class="py-src-keyword">def</span> <span class="py-src-identifier">setUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>, <span class="py-src-parameter">status</span>):
581
<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span>[<span class="py-src-variable">user</span>] = <span class="py-src-variable">status</span>
584
<span class="py-src-variable">f</span> = <span class="py-src-variable">MemoryFingerService</span>(<span class="py-src-variable">moshez</span>=<span class="py-src-string">'Happy and well'</span>)
585
<span class="py-src-variable">serviceCollection</span> = <span class="py-src-variable">service</span>.<span class="py-src-variable">IServiceCollection</span>(<span class="py-src-variable">application</span>)
586
<span class="py-src-variable">internet</span>.<span class="py-src-variable">TCPServer</span>(<span class="py-src-number">1079</span>, <span class="py-src-variable">IFingerSetterFactory</span>(<span class="py-src-variable">f</span>), <span class="py-src-variable">interface</span>=<span class="py-src-string">'127.0.0.1'</span>
587
).<span class="py-src-variable">setServiceParent</span>(<span class="py-src-variable">serviceCollection</span>)
588
</pre><div class="caption">Source listing - <a href="listings/finger/finger19a_changes.py"><span class="filename">listings/finger/finger19a_changes.py</span></a></div></div>
590
Full source code here: <div class="py-listing"><pre><p class="py-linenumber"> 1
821
</p><span class="py-src-comment"># Do everything properly, and componentize</span>
822
<span class="py-src-keyword">from</span> <span class="py-src-variable">twisted</span>.<span class="py-src-variable">application</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">internet</span>, <span class="py-src-variable">service</span>
823
<span class="py-src-keyword">from</span> <span class="py-src-variable">twisted</span>.<span class="py-src-variable">internet</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">protocol</span>, <span class="py-src-variable">reactor</span>, <span class="py-src-variable">defer</span>
824
<span class="py-src-keyword">from</span> <span class="py-src-variable">twisted</span>.<span class="py-src-variable">words</span>.<span class="py-src-variable">protocols</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">irc</span>
825
<span class="py-src-keyword">from</span> <span class="py-src-variable">twisted</span>.<span class="py-src-variable">protocols</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">basic</span>
826
<span class="py-src-keyword">from</span> <span class="py-src-variable">twisted</span>.<span class="py-src-variable">python</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">components</span>
827
<span class="py-src-keyword">from</span> <span class="py-src-variable">twisted</span>.<span class="py-src-variable">web</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">resource</span>, <span class="py-src-variable">server</span>, <span class="py-src-variable">static</span>, <span class="py-src-variable">xmlrpc</span>
828
<span class="py-src-keyword">from</span> <span class="py-src-variable">zope</span>.<span class="py-src-variable">interface</span> <span class="py-src-keyword">import</span> <span class="py-src-variable">Interface</span>, <span class="py-src-variable">implements</span>
829
<span class="py-src-keyword">import</span> <span class="py-src-variable">cgi</span>
831
<span class="py-src-keyword">class</span> <span class="py-src-identifier">IFingerService</span>(<span class="py-src-parameter">Interface</span>):
833
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">user</span>):
834
<span class="py-src-string">"""Return a deferred returning a string"""</span>
836
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUsers</span>():
837
<span class="py-src-string">"""Return a deferred returning a list of strings"""</span>
839
<span class="py-src-keyword">class</span> <span class="py-src-identifier">IFingerSetterService</span>(<span class="py-src-parameter">Interface</span>):
841
<span class="py-src-keyword">def</span> <span class="py-src-identifier">setUser</span>(<span class="py-src-parameter">user</span>, <span class="py-src-parameter">status</span>):
842
<span class="py-src-string">"""Set the user's status to something"""</span>
844
<span class="py-src-keyword">def</span> <span class="py-src-identifier">catchError</span>(<span class="py-src-parameter">err</span>):
845
<span class="py-src-keyword">return</span> <span class="py-src-string">"Internal error in server"</span>
847
<span class="py-src-keyword">class</span> <span class="py-src-identifier">FingerProtocol</span>(<span class="py-src-parameter">basic</span>.<span class="py-src-parameter">LineReceiver</span>):
849
<span class="py-src-keyword">def</span> <span class="py-src-identifier">lineReceived</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>):
850
<span class="py-src-variable">d</span> = <span class="py-src-variable">self</span>.<span class="py-src-variable">factory</span>.<span class="py-src-variable">getUser</span>(<span class="py-src-variable">user</span>)
851
<span class="py-src-variable">d</span>.<span class="py-src-variable">addErrback</span>(<span class="py-src-variable">catchError</span>)
852
<span class="py-src-keyword">def</span> <span class="py-src-identifier">writeValue</span>(<span class="py-src-parameter">value</span>):
853
<span class="py-src-variable">self</span>.<span class="py-src-variable">transport</span>.<span class="py-src-variable">write</span>(<span class="py-src-variable">value</span>+<span class="py-src-string">'\r\n'</span>)
854
<span class="py-src-variable">self</span>.<span class="py-src-variable">transport</span>.<span class="py-src-variable">loseConnection</span>()
855
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-variable">writeValue</span>)
858
<span class="py-src-keyword">class</span> <span class="py-src-identifier">IFingerFactory</span>(<span class="py-src-parameter">Interface</span>):
860
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">user</span>):
861
<span class="py-src-string">"""Return a deferred returning a string"""</span>
863
<span class="py-src-keyword">def</span> <span class="py-src-identifier">buildProtocol</span>(<span class="py-src-parameter">addr</span>):
864
<span class="py-src-string">"""Return a protocol returning a string"""</span>
867
<span class="py-src-keyword">class</span> <span class="py-src-identifier">FingerFactoryFromService</span>(<span class="py-src-parameter">protocol</span>.<span class="py-src-parameter">ServerFactory</span>):
869
<span class="py-src-variable">implements</span>(<span class="py-src-variable">IFingerFactory</span>)
871
<span class="py-src-variable">protocol</span> = <span class="py-src-variable">FingerProtocol</span>
873
<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">service</span>):
874
<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span> = <span class="py-src-variable">service</span>
876
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>):
877
<span class="py-src-keyword">return</span> <span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>.<span class="py-src-variable">getUser</span>(<span class="py-src-variable">user</span>)
879
<span class="py-src-variable">components</span>.<span class="py-src-variable">registerAdapter</span>(<span class="py-src-variable">FingerFactoryFromService</span>,
880
<span class="py-src-variable">IFingerService</span>,
881
<span class="py-src-variable">IFingerFactory</span>)
883
<span class="py-src-keyword">class</span> <span class="py-src-identifier">FingerSetterProtocol</span>(<span class="py-src-parameter">basic</span>.<span class="py-src-parameter">LineReceiver</span>):
885
<span class="py-src-keyword">def</span> <span class="py-src-identifier">connectionMade</span>(<span class="py-src-parameter">self</span>):
886
<span class="py-src-variable">self</span>.<span class="py-src-variable">lines</span> = []
888
<span class="py-src-keyword">def</span> <span class="py-src-identifier">lineReceived</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">line</span>):
889
<span class="py-src-variable">self</span>.<span class="py-src-variable">lines</span>.<span class="py-src-variable">append</span>(<span class="py-src-variable">line</span>)
891
<span class="py-src-keyword">def</span> <span class="py-src-identifier">connectionLost</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">reason</span>):
892
<span class="py-src-keyword">if</span> <span class="py-src-variable">len</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">lines</span>) == <span class="py-src-number">2</span>:
893
<span class="py-src-variable">self</span>.<span class="py-src-variable">factory</span>.<span class="py-src-variable">setUser</span>(*<span class="py-src-variable">self</span>.<span class="py-src-variable">lines</span>)
896
<span class="py-src-keyword">class</span> <span class="py-src-identifier">IFingerSetterFactory</span>(<span class="py-src-parameter">Interface</span>):
898
<span class="py-src-keyword">def</span> <span class="py-src-identifier">setUser</span>(<span class="py-src-parameter">user</span>, <span class="py-src-parameter">status</span>):
899
<span class="py-src-string">"""Return a deferred returning a string"""</span>
901
<span class="py-src-keyword">def</span> <span class="py-src-identifier">buildProtocol</span>(<span class="py-src-parameter">addr</span>):
902
<span class="py-src-string">"""Return a protocol returning a string"""</span>
905
<span class="py-src-keyword">class</span> <span class="py-src-identifier">FingerSetterFactoryFromService</span>(<span class="py-src-parameter">protocol</span>.<span class="py-src-parameter">ServerFactory</span>):
907
<span class="py-src-variable">implements</span>(<span class="py-src-variable">IFingerSetterFactory</span>)
909
<span class="py-src-variable">protocol</span> = <span class="py-src-variable">FingerSetterProtocol</span>
911
<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">service</span>):
912
<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span> = <span class="py-src-variable">service</span>
914
<span class="py-src-keyword">def</span> <span class="py-src-identifier">setUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>, <span class="py-src-parameter">status</span>):
915
<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>.<span class="py-src-variable">setUser</span>(<span class="py-src-variable">user</span>, <span class="py-src-variable">status</span>)
918
<span class="py-src-variable">components</span>.<span class="py-src-variable">registerAdapter</span>(<span class="py-src-variable">FingerSetterFactoryFromService</span>,
919
<span class="py-src-variable">IFingerSetterService</span>,
920
<span class="py-src-variable">IFingerSetterFactory</span>)
922
<span class="py-src-keyword">class</span> <span class="py-src-identifier">IRCReplyBot</span>(<span class="py-src-parameter">irc</span>.<span class="py-src-parameter">IRCClient</span>):
924
<span class="py-src-keyword">def</span> <span class="py-src-identifier">connectionMade</span>(<span class="py-src-parameter">self</span>):
925
<span class="py-src-variable">self</span>.<span class="py-src-variable">nickname</span> = <span class="py-src-variable">self</span>.<span class="py-src-variable">factory</span>.<span class="py-src-variable">nickname</span>
926
<span class="py-src-variable">irc</span>.<span class="py-src-variable">IRCClient</span>.<span class="py-src-variable">connectionMade</span>(<span class="py-src-variable">self</span>)
928
<span class="py-src-keyword">def</span> <span class="py-src-identifier">privmsg</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>, <span class="py-src-parameter">channel</span>, <span class="py-src-parameter">msg</span>):
929
<span class="py-src-variable">user</span> = <span class="py-src-variable">user</span>.<span class="py-src-variable">split</span>(<span class="py-src-string">'!'</span>)[<span class="py-src-number">0</span>]
930
<span class="py-src-keyword">if</span> <span class="py-src-variable">self</span>.<span class="py-src-variable">nickname</span>.<span class="py-src-variable">lower</span>() == <span class="py-src-variable">channel</span>.<span class="py-src-variable">lower</span>():
931
<span class="py-src-variable">d</span> = <span class="py-src-variable">self</span>.<span class="py-src-variable">factory</span>.<span class="py-src-variable">getUser</span>(<span class="py-src-variable">msg</span>)
932
<span class="py-src-variable">d</span>.<span class="py-src-variable">addErrback</span>(<span class="py-src-variable">catchError</span>)
933
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-keyword">lambda</span> <span class="py-src-variable">m</span>: <span class="py-src-string">"Status of %s: %s"</span> % (<span class="py-src-variable">msg</span>, <span class="py-src-variable">m</span>))
934
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-keyword">lambda</span> <span class="py-src-variable">m</span>: <span class="py-src-variable">self</span>.<span class="py-src-variable">msg</span>(<span class="py-src-variable">user</span>, <span class="py-src-variable">m</span>))
937
<span class="py-src-keyword">class</span> <span class="py-src-identifier">IIRCClientFactory</span>(<span class="py-src-parameter">Interface</span>):
939
<span class="py-src-string">"""
941
"""</span>
943
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">user</span>):
944
<span class="py-src-string">"""Return a deferred returning a string"""</span>
946
<span class="py-src-keyword">def</span> <span class="py-src-identifier">buildProtocol</span>(<span class="py-src-parameter">addr</span>):
947
<span class="py-src-string">"""Return a protocol"""</span>
950
<span class="py-src-keyword">class</span> <span class="py-src-identifier">IRCClientFactoryFromService</span>(<span class="py-src-parameter">protocol</span>.<span class="py-src-parameter">ClientFactory</span>):
952
<span class="py-src-variable">implements</span>(<span class="py-src-variable">IIRCClientFactory</span>)
954
<span class="py-src-variable">protocol</span> = <span class="py-src-variable">IRCReplyBot</span>
955
<span class="py-src-variable">nickname</span> = <span class="py-src-variable">None</span>
957
<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">service</span>):
958
<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span> = <span class="py-src-variable">service</span>
960
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>):
961
<span class="py-src-keyword">return</span> <span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>.<span class="py-src-variable">getUser</span>(<span class="py-src-variable">user</span>)
963
<span class="py-src-variable">components</span>.<span class="py-src-variable">registerAdapter</span>(<span class="py-src-variable">IRCClientFactoryFromService</span>,
964
<span class="py-src-variable">IFingerService</span>,
965
<span class="py-src-variable">IIRCClientFactory</span>)
967
<span class="py-src-keyword">class</span> <span class="py-src-identifier">UserStatusTree</span>(<span class="py-src-parameter">resource</span>.<span class="py-src-parameter">Resource</span>):
969
<span class="py-src-variable">implements</span>(<span class="py-src-variable">resource</span>.<span class="py-src-variable">IResource</span>)
971
<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">service</span>):
972
<span class="py-src-variable">resource</span>.<span class="py-src-variable">Resource</span>.<span class="py-src-variable">__init__</span>(<span class="py-src-variable">self</span>)
973
<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span> = <span class="py-src-variable">service</span>
974
<span class="py-src-variable">self</span>.<span class="py-src-variable">putChild</span>(<span class="py-src-string">'RPC2'</span>, <span class="py-src-variable">UserStatusXR</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>))
976
<span class="py-src-keyword">def</span> <span class="py-src-identifier">render_GET</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">request</span>):
977
<span class="py-src-variable">d</span> = <span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>.<span class="py-src-variable">getUsers</span>()
978
<span class="py-src-keyword">def</span> <span class="py-src-identifier">formatUsers</span>(<span class="py-src-parameter">users</span>):
979
<span class="py-src-variable">l</span> = [<span class="py-src-string">'<li><a href="%s">%s</a></li>'</span> % (<span class="py-src-variable">user</span>, <span class="py-src-variable">user</span>)
980
<span class="py-src-keyword">for</span> <span class="py-src-variable">user</span> <span class="py-src-keyword">in</span> <span class="py-src-variable">users</span>]
981
<span class="py-src-keyword">return</span> <span class="py-src-string">'<ul>'</span>+<span class="py-src-string">''</span>.<span class="py-src-variable">join</span>(<span class="py-src-variable">l</span>)+<span class="py-src-string">'</ul>'</span>
982
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-variable">formatUsers</span>)
983
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-variable">request</span>.<span class="py-src-variable">write</span>)
984
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-keyword">lambda</span> <span class="py-src-variable">_</span>: <span class="py-src-variable">request</span>.<span class="py-src-variable">finish</span>())
985
<span class="py-src-keyword">return</span> <span class="py-src-variable">server</span>.<span class="py-src-variable">NOT_DONE_YET</span>
987
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getChild</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">path</span>, <span class="py-src-parameter">request</span>):
988
<span class="py-src-keyword">if</span> <span class="py-src-variable">path</span>==<span class="py-src-string">""</span>:
989
<span class="py-src-keyword">return</span> <span class="py-src-variable">UserStatusTree</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>)
990
<span class="py-src-keyword">else</span>:
991
<span class="py-src-keyword">return</span> <span class="py-src-variable">UserStatus</span>(<span class="py-src-variable">path</span>, <span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>)
993
<span class="py-src-variable">components</span>.<span class="py-src-variable">registerAdapter</span>(<span class="py-src-variable">UserStatusTree</span>, <span class="py-src-variable">IFingerService</span>,
994
<span class="py-src-variable">resource</span>.<span class="py-src-variable">IResource</span>)
996
<span class="py-src-keyword">class</span> <span class="py-src-identifier">UserStatus</span>(<span class="py-src-parameter">resource</span>.<span class="py-src-parameter">Resource</span>):
998
<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>, <span class="py-src-parameter">service</span>):
999
<span class="py-src-variable">resource</span>.<span class="py-src-variable">Resource</span>.<span class="py-src-variable">__init__</span>(<span class="py-src-variable">self</span>)
1000
<span class="py-src-variable">self</span>.<span class="py-src-variable">user</span> = <span class="py-src-variable">user</span>
1001
<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span> = <span class="py-src-variable">service</span>
1003
<span class="py-src-keyword">def</span> <span class="py-src-identifier">render_GET</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">request</span>):
1004
<span class="py-src-variable">d</span> = <span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>.<span class="py-src-variable">getUser</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">user</span>)
1005
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-variable">cgi</span>.<span class="py-src-variable">escape</span>)
1006
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-keyword">lambda</span> <span class="py-src-variable">m</span>:
1007
<span class="py-src-string">'<h1>%s</h1>'</span>%<span class="py-src-variable">self</span>.<span class="py-src-variable">user</span>+<span class="py-src-string">'<p>%s</p>'</span>%<span class="py-src-variable">m</span>)
1008
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-variable">request</span>.<span class="py-src-variable">write</span>)
1009
<span class="py-src-variable">d</span>.<span class="py-src-variable">addCallback</span>(<span class="py-src-keyword">lambda</span> <span class="py-src-variable">_</span>: <span class="py-src-variable">request</span>.<span class="py-src-variable">finish</span>())
1010
<span class="py-src-keyword">return</span> <span class="py-src-variable">server</span>.<span class="py-src-variable">NOT_DONE_YET</span>
1013
<span class="py-src-keyword">class</span> <span class="py-src-identifier">UserStatusXR</span>(<span class="py-src-parameter">xmlrpc</span>.<span class="py-src-parameter">XMLRPC</span>):
1015
<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">service</span>):
1016
<span class="py-src-variable">xmlrpc</span>.<span class="py-src-variable">XMLRPC</span>.<span class="py-src-variable">__init__</span>(<span class="py-src-variable">self</span>)
1017
<span class="py-src-variable">self</span>.<span class="py-src-variable">service</span> = <span class="py-src-variable">service</span>
1019
<span class="py-src-keyword">def</span> <span class="py-src-identifier">xmlrpc_getUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>):
1020
<span class="py-src-keyword">return</span> <span class="py-src-variable">self</span>.<span class="py-src-variable">service</span>.<span class="py-src-variable">getUser</span>(<span class="py-src-variable">user</span>)
1022
<span class="py-src-keyword">class</span> <span class="py-src-identifier">MemoryFingerService</span>(<span class="py-src-parameter">service</span>.<span class="py-src-parameter">Service</span>):
1024
<span class="py-src-variable">implements</span>([<span class="py-src-variable">IFingerService</span>, <span class="py-src-variable">IFingerSetterService</span>])
1026
<span class="py-src-keyword">def</span> <span class="py-src-identifier">__init__</span>(<span class="py-src-parameter">self</span>, **<span class="py-src-parameter">kwargs</span>):
1027
<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span> = <span class="py-src-variable">kwargs</span>
1029
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>):
1030
<span class="py-src-keyword">return</span> <span class="py-src-variable">defer</span>.<span class="py-src-variable">succeed</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span>.<span class="py-src-variable">get</span>(<span class="py-src-variable">user</span>, <span class="py-src-string">"No such user"</span>))
1032
<span class="py-src-keyword">def</span> <span class="py-src-identifier">getUsers</span>(<span class="py-src-parameter">self</span>):
1033
<span class="py-src-keyword">return</span> <span class="py-src-variable">defer</span>.<span class="py-src-variable">succeed</span>(<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span>.<span class="py-src-variable">keys</span>())
1035
<span class="py-src-keyword">def</span> <span class="py-src-identifier">setUser</span>(<span class="py-src-parameter">self</span>, <span class="py-src-parameter">user</span>, <span class="py-src-parameter">status</span>):
1036
<span class="py-src-variable">self</span>.<span class="py-src-variable">users</span>[<span class="py-src-variable">user</span>] = <span class="py-src-variable">status</span>
1039
<span class="py-src-variable">application</span> = <span class="py-src-variable">service</span>.<span class="py-src-variable">Application</span>(<span class="py-src-string">'finger'</span>, <span class="py-src-variable">uid</span>=<span class="py-src-number">1</span>, <span class="py-src-variable">gid</span>=<span class="py-src-number">1</span>)
1040
<span class="py-src-variable">f</span> = <span class="py-src-variable">MemoryFingerService</span>(<span class="py-src-variable">moshez</span>=<span class="py-src-string">'Happy and well'</span>)
1041
<span class="py-src-variable">serviceCollection</span> = <span class="py-src-variable">service</span>.<span class="py-src-variable">IServiceCollection</span>(<span class="py-src-variable">application</span>)
1042
<span class="py-src-variable">internet</span>.<span class="py-src-variable">TCPServer</span>(<span class="py-src-number">79</span>, <span class="py-src-variable">IFingerFactory</span>(<span class="py-src-variable">f</span>)
1043
).<span class="py-src-variable">setServiceParent</span>(<span class="py-src-variable">serviceCollection</span>)
1044
<span class="py-src-variable">internet</span>.<span class="py-src-variable">TCPServer</span>(<span class="py-src-number">8000</span>, <span class="py-src-variable">server</span>.<span class="py-src-variable">Site</span>(<span class="py-src-variable">resource</span>.<span class="py-src-variable">IResource</span>(<span class="py-src-variable">f</span>))
1045
).<span class="py-src-variable">setServiceParent</span>(<span class="py-src-variable">serviceCollection</span>)
1046
<span class="py-src-variable">i</span> = <span class="py-src-variable">IIRCClientFactory</span>(<span class="py-src-variable">f</span>)
1047
<span class="py-src-variable">i</span>.<span class="py-src-variable">nickname</span> = <span class="py-src-string">'fingerbot'</span>
1048
<span class="py-src-variable">internet</span>.<span class="py-src-variable">TCPClient</span>(<span class="py-src-string">'irc.freenode.org'</span>, <span class="py-src-number">6667</span>, <span class="py-src-variable">i</span>
1049
).<span class="py-src-variable">setServiceParent</span>(<span class="py-src-variable">serviceCollection</span>)
1050
<span class="py-src-variable">internet</span>.<span class="py-src-variable">TCPServer</span>(<span class="py-src-number">1079</span>, <span class="py-src-variable">IFingerSetterFactory</span>(<span class="py-src-variable">f</span>), <span class="py-src-variable">interface</span>=<span class="py-src-string">'127.0.0.1'</span>
1051
).<span class="py-src-variable">setServiceParent</span>(<span class="py-src-variable">serviceCollection</span>)
1052
</pre><div class="caption">Source listing - <a href="listings/finger/finger19a.tac"><span class="filename">listings/finger/finger19a.tac</span></a></div></div>
1055
<h2>Aspect-Oriented Programming<a name="auto3"/></h2>
1057
<p>At last, an example of aspect-oriented programming that isn't about logging
1058
or timing. This code is actually useful! Watch how aspect-oriented programming
1059
helps you write less code and have fewer dependencies!
1065
<p><a href="../index.html">Index</a></p>
1066
<span class="version">Version: 10.0.0</span>
b'\\ No newline at end of file'