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<div class="refentry" title="is_cached()">
<a name="api.is.cached"></a><div class="titlepage"></div>
<div class="refnamediv">
<h2>Name</h2>
<p>is_cached() — returns true if there is a valid cache for this template</p>
</div>
<div class="refsect1" title="Description">
<a name="id3102271"></a><h2>Description</h2>
<code class="methodsynopsis"><span class="type">bool </span><span class="methodname">is_cached</span>(<span class="methodparam"><span class="type">string </span><span class="parameter">template</span></span>,<br> <span class="methodparam"><span class="type">string </span><span class="parameter">cache_id</span></span>,<br> <span class="methodparam"><span class="type">string </span><span class="parameter">compile_id</span></span>);</code><div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem"><p>
This only works if <a class="link" href="variable.caching.html" title="$caching">
<em class="parameter"><code>$caching</code></em></a> is set to <code class="constant">TRUE</code>, see the
<a class="link" href="caching.html" title="Chapter 14. Caching">caching section</a> for more info.
</p></li>
<li class="listitem"><p>
You can also pass a <em class="parameter"><code>$cache_id</code></em> as an optional second
parameter in case you want
<a class="link" href="caching.multiple.caches.html" title="Multiple Caches Per Page">multiple caches</a>
for the given template.
</p></li>
<li class="listitem"><p>
You can supply a
<a class="link" href="variable.compile.id.html" title="$compile_id"><em class="parameter"><code>$compile id</code></em></a>
as an optional third parameter. If you omit that parameter the persistent
<a class="link" href="variable.compile.id.html" title="$compile_id">
<em class="parameter"><code>$compile_id</code></em></a> is used if its set.
</p></li>
<li class="listitem"><p>
If you do not want to pass a <em class="parameter"><code>$cache_id</code></em> but want to
pass a <a class="link" href="variable.compile.id.html" title="$compile_id">
<em class="parameter"><code>$compile_id</code></em></a> you have to pass
<code class="constant">NULL</code> as a <em class="parameter"><code>$cache_id</code></em>.
</p></li>
</ul></div>
<div class="note" title="Technical Note" style="margin-left: 0.5in; margin-right: 0.5in;">
<h3 class="title">Technical Note</h3>
<p>
If <code class="varname">is_cached()</code> returns <code class="constant">TRUE</code> it actually loads the
cached output and stores it internally. Any subsequent call to
<a class="link" href="api.display.html" title="display()"><code class="varname">display()</code></a> or
<a class="link" href="api.fetch.html" title="fetch()"><code class="varname">fetch()</code></a>
will return this internally stored output and does not try to reload
the cache file. This prevents a race condition that may occur when a
second process clears the cache between the calls to
<code class="varname">is_cached()</code> and to
<a class="link" href="api.display.html" title="display()"><code class="varname">display()</code></a>
in the example above. This also means calls to
<a class="link" href="api.clear.cache.html" title="clear_cache()"><code class="varname">clear_cache()</code></a>
and other changes of the cache-settings may have no effect after
<code class="varname">is_cached()</code> returned <code class="constant">TRUE</code>.
</p>
</div>
<div class="example">
<a name="id3102825"></a><p class="title"><b>Example 13.19. is_cached()</b></p>
<div class="example-contents"><pre class="programlisting">
<?php
$smarty->caching = true;
if(!$smarty->is_cached('index.tpl')) {
// do database calls, assign vars here
}
$smarty->display('index.tpl');
?>
</pre></div>
</div>
<br class="example-break"><div class="example">
<a name="id3102839"></a><p class="title"><b>Example 13.20. is_cached() with multiple-cache template</b></p>
<div class="example-contents"><pre class="programlisting">
<?php
$smarty->caching = true;
if(!$smarty->is_cached('index.tpl', 'FrontPage')) {
// do database calls, assign vars here
}
$smarty->display('index.tpl', 'FrontPage');
?>
</pre></div>
</div>
<br class="example-break"><p>
See also
<a class="link" href="api.clear.cache.html" title="clear_cache()"><code class="varname">clear_cache()</code></a>,
<a class="link" href="api.clear.all.cache.html" title="clear_all_cache()"><code class="varname">clear_all_cache()</code></a>,
and
<a class="link" href="caching.html" title="Chapter 14. Caching">caching section</a>.
</p>
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