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| <h1 class="content-header header-section1" id="ref_directive_userDefined" itemprop="headline">User-defined directive (<@...>)</h1> |
| </div></div><div class="page-menu"> |
| <div class="page-menu-title">Page Contents</div> |
| <ul><li><a class="page-menu-link" href="#autoid_102" data-menu-target="autoid_102">Synopsis</a></li><li><a class="page-menu-link" href="#autoid_103" data-menu-target="autoid_103">Description</a><ul><li><a class="page-menu-link" href="#ref_directive_userDefined_entTag" data-menu-target="ref_directive_userDefined_entTag">End-tag</a></li><li><a class="page-menu-link" href="#ref_directive_userDefined_loopVar" data-menu-target="ref_directive_userDefined_loopVar">Loop variables</a></li><li><a class="page-menu-link" href="#ref_directive_userDefined_positionalParam" data-menu-target="ref_directive_userDefined_positionalParam">Positional parameter passing</a></li></ul></li></ul> </div><a name="ref.directive.userDefined"></a> |
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| |
| |
| |
| <h2 class="content-header header-section2" id="autoid_102">Synopsis</h2> |
| |
| |
| |
| <pre class="metaTemplate"> |
| <code class="inline-code"><@<em class="code-color">user_def_dir_exp</em> <em class="code-color">param1</em>=<em class="code-color">val1</em> <em class="code-color">param2</em>=<em class="code-color">val2</em> <em class="code-color">...</em> <em class="code-color">paramN</em>=<em class="code-color">valN</em>/></code> |
| (Note the XML-style <code class="inline-code">/</code> before the <code class="inline-code">></code>) |
| or if you need loop variables (<a href="#ref_directive_userDefined_loopVar">more details...</a>) |
| <code class="inline-code"><@<em class="code-color">user_def_dir_exp</em> <em class="code-color">param1</em>=<em class="code-color">val1</em> <em class="code-color">param2</em>=<em class="code-color">val2</em> <em class="code-color">...</em> <em class="code-color">paramN</em>=<em class="code-color">valN</em> ; <em class="code-color">lv1</em>, <em class="code-color">lv2</em>, <em class="code-color">...</em>, <em class="code-color">lvN</em>/></code> |
| |
| Or the same as the above two but with end-tag (<a href="#ref_directive_userDefined_entTag">more details...</a>): |
| |
| <code class="inline-code"><@<em class="code-color">user_def_dir_exp</em> <em class="code-color">...</em>> |
| ... |
| </@<em class="code-color">user_def_dir_exp</em>></code> |
| or |
| <code class="inline-code"><@<em class="code-color">user_def_dir_exp</em> <em class="code-color">...</em>> |
| ... |
| </@></code> |
| |
| Or all above but with positional parameter passing (<a href="#ref_directive_userDefined_positionalParam">more details...</a>): |
| |
| <code class="inline-code"><@<em class="code-color">user</em> <em class="code-color">val1</em>, <em class="code-color">val2</em>, <em class="code-color">...</em>, <em class="code-color">valN</em>/></code> |
| ...etc. |
| </pre> |
| |
| |
| <p>Where:</p> |
| |
| <ul> |
| <li> |
| <code class="inline-code"><em class="code-color">user_def_dir_exp</em></code>: |
| Expression evaluates to an user-defined directive (for example a |
| macro), that will be called. |
| </li> |
| |
| <li> |
| <code class="inline-code"><em class="code-color">param1</em></code>, |
| <code class="inline-code"><em class="code-color">param2</em></code>, ...etc.: |
| The name of parameters. They are <em>not</em> |
| expressions. |
| </li> |
| |
| <li> |
| <code class="inline-code"><em class="code-color">val1</em></code>, |
| <code class="inline-code"><em class="code-color">val2</em></code>, ...etc.: The |
| value of parameters. They <em>are</em> |
| expressions. |
| </li> |
| |
| <li> |
| <code class="inline-code"><em class="code-color">lv1</em></code>, |
| <code class="inline-code"><em class="code-color">lv2</em></code>, ...etc.: The |
| name of <a href="dgui_misc_var.html">loop variables</a>. |
| They are <em>not</em> expressions. |
| </li> |
| </ul> |
| |
| <p>The number of parameters can be 0 (i.e. no parameters).</p> |
| |
| <p>The order of parameters is not significant (unless you use |
| positional parameter passing). The name of parameters must be |
| unique. Lower- and uppercase letters are considered as different |
| letters in parameter names (i.e. <code class="inline-code">Color</code> and |
| <code class="inline-code">color</code> is not the same).</p> |
| |
| |
| |
| |
| |
| <h2 class="content-header header-section2" id="autoid_103">Description</h2> |
| |
| |
| <p>This will call an user-defined directive, for example a macro. |
| The meaning of parameters, and the set of supported and required |
| parameters depend on the concrete user-defined directive.</p> |
| |
| <p>You may read <a href="dgui_misc_userdefdir.html">the tutorial |
| about user-defined directives</a>.</p> |
| |
| <p>Example 1: Calls the directive that is stored in the variable |
| <code class="inline-code">html_escape</code>:</p> |
| |
| |
| |
| <div class="code-wrapper"><pre class="code-block code-template"><@html_escape> |
| a < b |
| Romeo & Juliet |
| </@html_escape></pre></div> |
| |
| <p>Output:</p> |
| |
| |
| |
| <div class="code-wrapper"><pre class="code-block code-output"> a &lt; b |
| Romeo &amp; Juliet</pre></div> |
| |
| <p>Example 2: Calls a macro with parameters:</p> |
| |
| |
| |
| <div class="code-wrapper"><pre class="code-block code-template"><@list items=["mouse", "elephant", "python"] title="Animals"/> |
| <em>...</em> |
| <#macro list title items> |
| <p>${title?cap_first}: |
| <ul> |
| <#list items as x> |
| <li>${x?cap_first} |
| </#list> |
| </ul> |
| </#macro></pre></div> |
| |
| <p>Output:</p> |
| |
| |
| |
| <div class="code-wrapper"><pre class="code-block code-output"> <p>Animals: |
| <ul> |
| <li>Mouse |
| <li>Elephant |
| <li>Python |
| </ul> |
| |
| <em>...</em></pre></div> |
| |
| |
| |
| |
| |
| |
| <h3 class="content-header header-section3" id="ref_directive_userDefined_entTag">End-tag</h3> |
| |
| |
| <p>You can omit the |
| <code class="inline-code"><em class="code-color">user_def_dir_exp</em></code> in |
| the <a href="gloss.html#gloss.endTag">end-tag</a>. That is, you can |
| always write <code class="inline-code"></@></code> instead of |
| <code class="inline-code"></@<em class="code-color">anything</em>></code>. |
| This rule is mostly useful when the |
| <code class="inline-code"><em class="code-color">user_def_dir_exp</em></code> |
| expression is too complex, because you don't have to repeat the |
| expression in the end-tag. Furthermore, if the expression contains |
| other than simple variable names and dots, you are not allowed to |
| repeat the expression. For example, |
| <code class="inline-code"><@a_hash[a_method()]><em class="code-color">...</em></@a_hash[a_method()]></code> |
| is an error; you must write |
| <code class="inline-code"><@a_hash[a_method()]><em class="code-color">...</em></@></code>. |
| But |
| <code class="inline-code"><@a_hash.foo><em class="code-color">...</em></@a_hash.foo></code> |
| is OK.</p> |
| |
| |
| |
| |
| |
| |
| |
| <h3 class="content-header header-section3" id="ref_directive_userDefined_loopVar">Loop variables</h3> |
| |
| |
| <p>Some user-defined directives create loop variables |
| (similarly to <code class="inline-code">list</code> directive). As with the |
| predefined directives (as <code class="inline-code">list</code>) the |
| <em>name</em> of loop variables is given when you call |
| the directive (as <code class="inline-code">foo</code> in <code class="inline-code"><#list |
| foos as |
| foo><em class="code-color">...</em></#list></code>), |
| while the <em>value</em> of the variable is set by the |
| directive itself. In the case of user-defined directives the |
| syntax is that the name of loop variables is given after a |
| semicolon. For example:</p> |
| |
| |
| |
| <div class="code-wrapper"><pre class="code-block code-template"><@myRepeatMacro count=4 ; <strong>x, last</strong>> |
| ${<strong>x</strong>}. Something... <#if <strong>last</strong>> This was the last!</#if> |
| </@myRepeatMacro></pre></div> |
| |
| <p>Note that the number of loop variable created by the |
| user-defined directive and the number of loop variables specified |
| after the semicolon need not match. Say, if you are not interested |
| if the repetition is the last, you can simply write:</p> |
| |
| |
| |
| <div class="code-wrapper"><pre class="code-block code-template"><@myRepeatMacro count=4 ; <strong>x</strong>> |
| ${<strong>x</strong>}. Something... |
| </@myRepeatMacro></pre></div> |
| |
| <p>or you can even:</p> |
| |
| |
| |
| <div class="code-wrapper"><pre class="code-block code-template"><@myRepeatMacro count=4> |
| Something... |
| </@myRepeatMacro></pre></div> |
| |
| <p>Furthermore, it does not cause error if you specify more |
| loop variables after the semicolon than the user-defined directive |
| creates, just the last few loop variables will not be created |
| (i.e. those will be undefined in the nested content). Trying to |
| use the undefined loop variables, however, will cause error |
| (unless you use built-ins like <code class="inline-code">?default</code>), since |
| you try to access a non-existing variable.</p> |
| |
| <p>See the <a href="dgui_misc_userdefdir.html">the tutorial |
| about user-defined directives</a> for more explanation.</p> |
| |
| |
| |
| |
| |
| |
| |
| <h3 class="content-header header-section3" id="ref_directive_userDefined_positionalParam">Positional parameter passing</h3> |
| |
| |
| |
| |
| <p>Positional parameter passing (as <code class="inline-code"><@heading |
| "Preface", 1/></code>) is a shorthand form of normal named |
| parameter passing (as <code class="inline-code"><@heading title="Preface" |
| level=1/></code>), where you omit the parameter name. This |
| shorthand form should be used if a user-defined directive has only |
| one parameter, or if it is easy to remember the order of |
| parameters for a frequently used user-defined directive. To use |
| this form, you have to know the order in which the named |
| parameters are declared (trivial if the directive has only one |
| parameter). Say, if <code class="inline-code">heading</code> was created as |
| <code class="inline-code"><#macro heading title |
| level><em class="code-color">...</em></code>, then |
| <code class="inline-code"><@heading "Preface", 1/></code> is equivalent |
| with <code class="inline-code"><@heading title="Preface" level=1/></code> |
| (or <code class="inline-code"><@heading level=1 title="Preface"/></code>; |
| if you use parameter names, the order is not important). Note that |
| positional parameter passing is currently only supported for |
| macros.</p> |
| |
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