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<h1 class="content-header header-section1" id="pgui_datamodel_parent" itemprop="headline">Containers</h1>
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<div class="page-menu-title">Page Contents</div>
<ul><li><a class="page-menu-link" href="#autoid_32" data-menu-target="autoid_32">Hashes</a></li><li><a class="page-menu-link" href="#autoid_33" data-menu-target="autoid_33">Sequences</a></li><li><a class="page-menu-link" href="#autoid_34" data-menu-target="autoid_34">Collections</a></li></ul> </div><p>These are hashes, sequences, and collections.</p>
<h2 class="content-header header-section2" id="autoid_32">Hashes</h2>
<p>Hashes are java objects that implement
<code class="inline-code">TemplateHashModel</code> interface.
<code class="inline-code">TemplateHashModel</code> contains two methods:
<code class="inline-code">TemplateModel get(String key)</code>, which returns the
subvariable of the given name, and <code class="inline-code">boolean
isEmpty()</code>, which indicates if the hash has zero
subvariable or not. The <code class="inline-code">get</code> method returns null
if no subvariable with the given name exists.</p>
<p>The <code class="inline-code">TemplateHashModelEx</code> interface extends
<code class="inline-code">TemplateHashModel</code>. It adds methods by which <a href="ref_builtins_hash.html#ref_builtin_values">values</a> and <a href="ref_builtins_hash.html#ref_builtin_keys">keys</a> built-ins can enumerate the
sub variables of the hash.</p>
<p>The commonly used implementation is
<code class="inline-code">SimpleHash</code>, which implements
<code class="inline-code">TemplateHashModelEx</code>. Internally it uses a
<code class="inline-code">java.util.Hash</code> to store the sub variables.
<code class="inline-code">SimpleHash</code> has methods by which you can add and
remove subvariable. These methods should be used to initialize the
variable directly after its creation.</p>
<p>Containers are immutable within FTL. That is, you can&#39;t add,
replace or remove the sub variables they contain.</p>
<h2 class="content-header header-section2" id="autoid_33">Sequences</h2>
<p>Sequences are java objects that implement
<code class="inline-code">TemplateSequenceModel</code>. It contains two methods:
<code class="inline-code">TemplateModel get(int index)</code> and <code class="inline-code">int
size()</code>.</p>
<p>The commonly used implementation is
<code class="inline-code">SimpleSequence</code>. It uses internally a
<code class="inline-code">java.util.List</code> to store its sub variables.
<code class="inline-code">SimpleSequence</code> has methods by which you can add
sub variables. These methods should be used to populate the sequence
directly after its creation.</p>
<h2 class="content-header header-section2" id="autoid_34">Collections</h2>
<p>Collections are java objects that implement the
<code class="inline-code">TemplateCollectionModel</code> interface. That interface
has one method: <code class="inline-code">TemplateModelIterator iterator()</code>.
The <code class="inline-code">TemplateModelIterator</code> interface is similar to
<code class="inline-code">java.util.Iterator</code>, but it returns
<code class="inline-code">TemplateModels</code> instead of
<code class="inline-code">Object</code>-s, and it can throw
<code class="inline-code">TemplateModelException</code>s.</p>
<p>The commonly used implementation is
<code class="inline-code">SimpleCollection</code>.</p>
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