280 lines
15 KiB
HTML
280 lines
15 KiB
HTML
<!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">
|
|
<head>
|
|
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|
|
|
<title>Change Tracking Policies — Doctrine MongoDB ODM 1.1.5 documentation</title>
|
|
<link rel="stylesheet" href="../_static/bootstrap/css/bootstrap.min.css" type="text/css" />
|
|
<link rel="stylesheet" href="../_static/default.css" type="text/css" />
|
|
<link rel="stylesheet" href="../_static/pygments.css" type="text/css" />
|
|
<link rel="stylesheet" href="../_static/layout.css" type="text/css" />
|
|
<link rel="stylesheet" href="../_static/configurationblock.css" type="text/css" />
|
|
<script type="text/javascript">
|
|
var DOCUMENTATION_OPTIONS = {
|
|
URL_ROOT: '../',
|
|
VERSION: '1.1.5',
|
|
COLLAPSE_MODINDEX: false,
|
|
FILE_SUFFIX: '.html',
|
|
HAS_SOURCE: true
|
|
};
|
|
</script>
|
|
|
|
<script type="text/javascript" src="../_static/jquery.js"></script>
|
|
<script type="text/javascript" src="../_static/configurationblock.js"></script>
|
|
<script type="text/javascript" src="../_static/underscore.js"></script>
|
|
<script type="text/javascript" src="../_static/configurationblock.js"></script>
|
|
<script type="text/javascript" src="../_static/doctools.js"></script>
|
|
<script type="text/javascript" src="../_static/configurationblock.js"></script>
|
|
<script src="../_static/bootstrap/js/bootstrap.min.js"></script>
|
|
|
|
<script type="text/javascript">
|
|
<!--
|
|
$(document).ready(function() {
|
|
$("#versions").change(function() {
|
|
var docsUrl = $(this).val();
|
|
window.location.href = docsUrl;
|
|
});
|
|
});
|
|
-->
|
|
</script>
|
|
<link rel="shortcut icon" href="../_static/doctrine.ico"/>
|
|
<link rel="search" title="Search" href="../search.html" />
|
|
<link rel="top" title="Doctrine MongoDB ODM 1.1.5 documentation" href="../index.html" />
|
|
</head>
|
|
<body>
|
|
<div id="wrapper">
|
|
<div id="header">
|
|
<h1 id="h1title"></h1>
|
|
<div id="logo">
|
|
<a href="http://www.doctrine-project.org/">Doctrine - PHP Database Libraries</a>
|
|
</div>
|
|
</div>
|
|
<div id="nav" class="cls">
|
|
<div class="tl cls">
|
|
<ul>
|
|
<li><a target="_top" href="http://www.doctrine-project.org/">Home</a></li>
|
|
<li><a target="_top" href="http://www.doctrine-project.org/about.html">About</a></li>
|
|
<li><a target="_top" href="http://www.doctrine-project.org/projects.html">Projects</a></li>
|
|
<li><a target="_top" href="http://www.doctrine-project.org/contribute.html">Contribute</a></li>
|
|
<li><a target="_top" href="http://www.doctrine-project.org/community.html">Community</a></li>
|
|
<li><a target="_top" href="http://www.doctrine-project.org/archive.html">Blog</a></li>
|
|
<li><a target="_top" href="http://www.doctrine-project.org/jira">Development</a></li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div id="content" class="cls">
|
|
<div class="related">
|
|
<h3>Navigation</h3>
|
|
<ul>
|
|
<li><a href="/">Doctrine Homepage</a> »</li>
|
|
<li><a href="../index.html">Doctrine MongoDB ODM 1.1.5 documentation</a> »</li>
|
|
</ul>
|
|
</div>
|
|
|
|
<div class="document">
|
|
<div class="documentwrapper">
|
|
<div class="bodywrapper">
|
|
|
|
<div class="body" >
|
|
|
|
<div class="section" id="change-tracking-policies">
|
|
<span id="id1"></span><h1>Change Tracking Policies<a class="headerlink" href="#change-tracking-policies" title="Permalink to this headline">¶</a></h1>
|
|
<p>Change tracking is the process of determining what has changed in
|
|
managed documents since the last time they were synchronized with
|
|
the database.</p>
|
|
<p>Doctrine provides 3 different change tracking policies, each having
|
|
its particular advantages and disadvantages. The change tracking
|
|
policy can be defined on a per-class basis (or more precisely,
|
|
per-hierarchy).</p>
|
|
<div class="section" id="deferred-implicit">
|
|
<h2>Deferred Implicit<a class="headerlink" href="#deferred-implicit" title="Permalink to this headline">¶</a></h2>
|
|
<p>The deferred implicit policy is the default change tracking policy
|
|
and the most convenient one. With this policy, Doctrine detects the
|
|
changes by a property-by-property comparison at commit time and
|
|
also detects changes to documents or new documents that are
|
|
referenced by other managed documents. Although the most convenient policy,
|
|
it can have negative effects on performance if you are dealing with large units
|
|
of work. Since Doctrine can't know what has changed, it needs to check
|
|
all managed documents for changes every time you invoke DocumentManager#flush(),
|
|
making this operation rather costly.</p>
|
|
</div>
|
|
<div class="section" id="deferred-explicit">
|
|
<h2>Deferred Explicit<a class="headerlink" href="#deferred-explicit" title="Permalink to this headline">¶</a></h2>
|
|
<p>The deferred explicit policy is similar to the deferred implicit
|
|
policy in that it detects changes through a property-by-property
|
|
comparison at commit time. The difference is that only documents are
|
|
considered that have been explicitly marked for change detection
|
|
through a call to DocumentManager#persist(document) or through a save
|
|
cascade. All other documents are skipped. This policy therefore
|
|
gives improved performance for larger units of work while
|
|
sacrificing the behavior of "automatic dirty checking".</p>
|
|
<p>Therefore, flush() operations are potentially cheaper with this
|
|
policy. The negative aspect this has is that if you have a rather
|
|
large application and you pass your objects through several layers
|
|
for processing purposes and business tasks you may need to track
|
|
yourself which documents have changed on the way so you can pass
|
|
them to DocumentManager#persist().</p>
|
|
<p>This policy can be configured as follows:</p>
|
|
<div class="highlight-php"><div class="highlight"><pre><span class="cp"><?php</span>
|
|
|
|
<span class="sd">/**</span>
|
|
<span class="sd"> * @Document</span>
|
|
<span class="sd"> * @ChangeTrackingPolicy("DEFERRED_EXPLICIT")</span>
|
|
<span class="sd"> */</span>
|
|
<span class="k">class</span> <span class="nc">User</span>
|
|
<span class="p">{</span>
|
|
<span class="c1">// ...</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
</div>
|
|
</div>
|
|
<div class="section" id="notify">
|
|
<h2>Notify<a class="headerlink" href="#notify" title="Permalink to this headline">¶</a></h2>
|
|
<p>This policy is based on the assumption that the documents notify
|
|
interested listeners of changes to their properties. For that
|
|
purpose, a class that wants to use this policy needs to implement
|
|
the <code class="docutils literal"><span class="pre">NotifyPropertyChanged</span></code> interface from the Doctrine
|
|
namespace. As a guideline, such an implementation can look as
|
|
follows:</p>
|
|
<div class="highlight-php"><div class="highlight"><pre><span class="cp"><?php</span>
|
|
|
|
<span class="k">use</span> <span class="nx">Doctrine\Common\NotifyPropertyChanged</span><span class="p">,</span>
|
|
<span class="nx">Doctrine\Common\PropertyChangedListener</span><span class="p">;</span>
|
|
|
|
<span class="sd">/**</span>
|
|
<span class="sd"> * @Document</span>
|
|
<span class="sd"> * @ChangeTrackingPolicy("NOTIFY")</span>
|
|
<span class="sd"> */</span>
|
|
<span class="k">class</span> <span class="nc">MyDocument</span> <span class="k">implements</span> <span class="nx">NotifyPropertyChanged</span>
|
|
<span class="p">{</span>
|
|
<span class="c1">// ...</span>
|
|
|
|
<span class="k">private</span> <span class="nv">$_listeners</span> <span class="o">=</span> <span class="k">array</span><span class="p">();</span>
|
|
|
|
<span class="k">public</span> <span class="k">function</span> <span class="nf">addPropertyChangedListener</span><span class="p">(</span><span class="nx">PropertyChangedListener</span> <span class="nv">$listener</span><span class="p">)</span>
|
|
<span class="p">{</span>
|
|
<span class="nv">$this</span><span class="o">-></span><span class="na">_listeners</span><span class="p">[]</span> <span class="o">=</span> <span class="nv">$listener</span><span class="p">;</span>
|
|
<span class="p">}</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>Then, in each property setter of this class or derived classes, you
|
|
need to notify all the <code class="docutils literal"><span class="pre">PropertyChangedListener</span></code> instances. As an
|
|
example we add a convenience method on <code class="docutils literal"><span class="pre">MyDocument</span></code> that shows this
|
|
behavior:</p>
|
|
<div class="highlight-php"><div class="highlight"><pre><span class="cp"><?php</span>
|
|
|
|
<span class="c1">// ...</span>
|
|
|
|
<span class="k">class</span> <span class="nc">MyDocument</span> <span class="k">implements</span> <span class="nx">NotifyPropertyChanged</span>
|
|
<span class="p">{</span>
|
|
<span class="c1">// ...</span>
|
|
|
|
<span class="k">protected</span> <span class="k">function</span> <span class="nf">_onPropertyChanged</span><span class="p">(</span><span class="nv">$propName</span><span class="p">,</span> <span class="nv">$oldValue</span><span class="p">,</span> <span class="nv">$newValue</span><span class="p">)</span>
|
|
<span class="p">{</span>
|
|
<span class="k">if</span> <span class="p">(</span><span class="nv">$this</span><span class="o">-></span><span class="na">_listeners</span><span class="p">)</span> <span class="p">{</span>
|
|
<span class="k">foreach</span> <span class="p">(</span><span class="nv">$this</span><span class="o">-></span><span class="na">_listeners</span> <span class="k">as</span> <span class="nv">$listener</span><span class="p">)</span> <span class="p">{</span>
|
|
<span class="nv">$listener</span><span class="o">-></span><span class="na">propertyChanged</span><span class="p">(</span><span class="nv">$this</span><span class="p">,</span> <span class="nv">$propName</span><span class="p">,</span> <span class="nv">$oldValue</span><span class="p">,</span> <span class="nv">$newValue</span><span class="p">);</span>
|
|
<span class="p">}</span>
|
|
<span class="p">}</span>
|
|
<span class="p">}</span>
|
|
|
|
<span class="k">public</span> <span class="k">function</span> <span class="nf">setData</span><span class="p">(</span><span class="nv">$data</span><span class="p">)</span>
|
|
<span class="p">{</span>
|
|
<span class="k">if</span> <span class="p">(</span><span class="nv">$data</span> <span class="o">!=</span> <span class="nv">$this</span><span class="o">-></span><span class="na">data</span><span class="p">)</span> <span class="p">{</span>
|
|
<span class="nv">$this</span><span class="o">-></span><span class="na">_onPropertyChanged</span><span class="p">(</span><span class="s1">'data'</span><span class="p">,</span> <span class="nv">$this</span><span class="o">-></span><span class="na">data</span><span class="p">,</span> <span class="nv">$data</span><span class="p">);</span>
|
|
<span class="nv">$this</span><span class="o">-></span><span class="na">data</span> <span class="o">=</span> <span class="nv">$data</span><span class="p">;</span>
|
|
<span class="p">}</span>
|
|
<span class="p">}</span>
|
|
<span class="p">}</span>
|
|
</pre></div>
|
|
</div>
|
|
<p>You have to invoke <code class="docutils literal"><span class="pre">_onPropertyChanged</span></code> inside every method that
|
|
changes the persistent state of <code class="docutils literal"><span class="pre">MyDocument</span></code>.</p>
|
|
<p>The check whether the new value is different from the old one is
|
|
not mandatory but recommended. That way you also have full control
|
|
over when you consider a property changed.</p>
|
|
<p>The negative point of this policy is obvious: You need implement an
|
|
interface and write some plumbing code. But also note that we tried
|
|
hard to keep this notification functionality abstract. Strictly
|
|
speaking, it has nothing to do with the persistence layer. You may
|
|
find that property notification events come in handy in many other
|
|
scenarios as well. As mentioned earlier, the <code class="docutils literal"><span class="pre">Doctrine\Common</span></code>
|
|
namespace is not that evil and consists solely of very small classes
|
|
and interfaces that have almost no external dependencies and that you can easily take with you should
|
|
you want to swap out the persistence layer. This change tracking policy
|
|
does not introduce a dependency on the Doctrine persistence
|
|
layer.</p>
|
|
<p>The positive point and main advantage of this policy is its
|
|
effectiveness. It has the best performance characteristics of the 3
|
|
policies with larger units of work and a flush() operation is very
|
|
cheap when nothing has changed.</p>
|
|
</div>
|
|
</div>
|
|
|
|
|
|
</div>
|
|
</div>
|
|
|
|
</div>
|
|
<div class="sphinxsidebar">
|
|
<div class="sphinxsidebarwrapper">
|
|
|
|
<div id="searchbox" style="">
|
|
<h3>Search</h3>
|
|
<form class="search" action="http://readthedocs.org/search/project/" method="get">
|
|
<input type="text" name="q" size="18">
|
|
<input type="submit" value="Go">
|
|
<input type="hidden" name="selected_facets" value="project:">
|
|
</form>
|
|
</div>
|
|
<h3><a href="../index.html">Table Of Contents</a></h3>
|
|
<ul>
|
|
<li><a class="reference internal" href="#">Change Tracking Policies</a><ul>
|
|
<li><a class="reference internal" href="#deferred-implicit">Deferred Implicit</a></li>
|
|
<li><a class="reference internal" href="#deferred-explicit">Deferred Explicit</a></li>
|
|
<li><a class="reference internal" href="#notify">Notify</a></li>
|
|
</ul>
|
|
</li>
|
|
</ul>
|
|
|
|
<h3>This Page</h3>
|
|
<ul class="this-page-menu">
|
|
<li><a href="../_sources/reference/change-tracking-policies.rst.txt"
|
|
rel="nofollow">Show Source</a></li>
|
|
</ul>
|
|
</div>
|
|
</div>
|
|
<div class="clearer"></div>
|
|
</div>
|
|
<div class="footer">
|
|
© Copyright 2013, Doctrine Project Team.
|
|
Created using <a href="http://sphinx.pocoo.org/">Sphinx</a> 1.6.2.
|
|
<br/>
|
|
<a target="_BLANK" href="http://www.servergrove.com"><img src="http://www.doctrine-project.org/_static/servergrove.jpg" /></a> <br/><br/>
|
|
<form action="https://www.paypal.com/cgi-bin/webscr" method="post">
|
|
<input type="hidden" name="cmd" value="_s-xclick" />
|
|
<input type="hidden" name="hosted_button_id" value="BAE2E3XANQ77Y" />
|
|
<input type="image" src="https://www.paypal.com/en_US/i/btn/btn_donateCC_LG.gif" border="0" name="submit" alt="PayPal - The safer, easier way to pay online!" />
|
|
<img alt="" border="0" src="https://www.paypal.com/en_US/i/scr/pixel.gif" width="1" height="1" />
|
|
</form>
|
|
</div>
|
|
</div>
|
|
|
|
<div id="bot-rcnr">
|
|
<div class="tl"><!-- corner --></div>
|
|
</div>
|
|
</div>
|
|
|
|
<script src="http://www.google-analytics.com/urchin.js" type="text/javascript">
|
|
</script>
|
|
<script type="text/javascript">
|
|
_uacct = "UA-288343-7";
|
|
urchinTracker();
|
|
</script>
|
|
<a class="githublink" href="http://github.com/doctrine"><img src="https://s3.amazonaws.com/github/ribbons/forkme_right_orange_ff7600.png" alt="Fork me on GitHub"></a>
|
|
</body>
|
|
</html> |