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| <h1 class="content-header header-section1" id="pgui_datamodel_method" itemprop="headline">Methods</h1> |
| </div></div><p>Method variables exposed to a template implement the |
| <code class="inline-code">TemplateMethodModel</code> interface. This contains one |
| method: <code class="inline-code">TemplateModel exec(java.util.List |
| arguments)</code>. When you call a method with a <a href="dgui_template_exp.html#dgui_template_exp_methodcall">method call expression</a>, |
| then the <code class="inline-code">exec</code> method will be called. The arguments |
| parameter will contain the values of the FTL method call arguments. |
| The return value of <code class="inline-code">exec</code> gives the value of the FTL |
| method call expression.</p><p>The <code class="inline-code">TemplateMethodModelEx</code> interface extends |
| <code class="inline-code">TemplateMethodModel</code>. It does not add any new |
| methods. The fact that the object implements this |
| <em>marker</em> interface indicates to the FTL engine that |
| the arguments should be put to the <code class="inline-code">java.util.List</code> |
| directly as <code class="inline-code">TemplateModel</code>-s. Otherwise they will be |
| put to the list as <code class="inline-code">String</code>-s.</p><p>For obvious reasons there is no default implementation for these |
| interfaces.</p><p>Example: This is a method, which returns the index within the |
| second string of the first occurrence of the first string, or -1 if |
| the second string doesn't contains the first.</p> |
| |
| <div class="code-block role-unspecified"> |
| <pre class="code-block-body">public class IndexOfMethod implements TemplateMethodModel { |
| |
| public TemplateModel exec(List args) throws TemplateModelException { |
| if (args.size() != 2) { |
| throw new TemplateModelException("Wrong arguments"); |
| } |
| return new SimpleNumber( |
| ((String) args.get(1)).indexOf((String) args.get(0))); |
| } |
| }</pre> </div> |
| <p>If you put an instance of this, say, into the root:</p> |
| |
| <div class="code-block role-unspecified"> |
| <pre class="code-block-body">root.put("indexOf", new IndexOfMethod());</pre> </div> |
| <p>then you can call it in the template:</p> |
| |
| <div class="code-block role-template"> |
| <div class="code-block-label">Template</div><pre class="code-block-body"><#assign x = "something"> |
| ${indexOf("met", x)} |
| ${indexOf("foo", x)}</pre> </div> |
| <p>and then the output will be:</p> |
| |
| <div class="code-block role-output"> |
| <div class="code-block-label">Output</div><pre class="code-block-body">2 |
| -1</pre> </div> |
| <p>If you need to access the runtime FTL environment (read/write |
| variables, get the current locale, etc.), you can get it with |
| <code class="inline-code">Environment.getCurrentEnvironment()</code>.</p><div class="bottom-pagers-wrapper"><div class="pagers bottom"><a class="paging-arrow previous" href="pgui_datamodel_parent.html"><span>Previous</span></a><a class="paging-arrow next" href="pgui_datamodel_directive.html"><span>Next</span></a></div></div></div></div> </div> |
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