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- <?xml version="1.0" encoding="UTF-8"?>
- <!-- Reviewed: no -->
- <sect1 id="zend.layout.quickstart">
- <title>Zend_Layout Quick Start</title>
- <para>
- There are two primary use cases for <classname>Zend_Layout</classname>: with the
- Zend Framework <acronym>MVC</acronym>, and without.
- </para>
- <sect2 id="zend.layout.quickstart.layouts">
- <title>Layout scripts</title>
- <para>
- In both cases, however, you'll need to create a layout script. Layout scripts simply
- utilize <classname>Zend_View</classname> (or whatever view implementation you are
- using). Layout variables are registered with a <classname>Zend_Layout</classname> <link
- linkend="zend.view.helpers.initial.placeholder">placeholder</link>,
- and may be accessed via the placeholder helper or by fetching them
- as object properties of the layout object via the layout helper.
- </para>
- <para>
- As an example:
- </para>
- <programlisting language="php"><![CDATA[
- <!DOCTYPE html
- PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
- "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
- <html>
- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
- <title>My Site</title>
- </head>
- <body>
- <?php
- // fetch 'content' key using layout helper:
- echo $this->layout()->content;
- // fetch 'foo' key using placeholder helper:
- echo $this->placeholder('Zend_Layout')->foo;
- // fetch layout object and retrieve various keys from it:
- $layout = $this->layout();
- echo $layout->bar;
- echo $layout->baz;
- ?>
- </body>
- </html>
- ]]></programlisting>
- <para>
- Because <classname>Zend_Layout</classname> utilizes <classname>Zend_View</classname> for
- rendering, you can also use any view helpers registered, and also
- have access to any previously assigned view variables. Particularly
- useful are the various <link
- linkend="zend.view.helpers.initial.placeholder">placeholder
- helpers</link>, as they allow you to
- retrieve content for areas such as the <head> section,
- navigation, etc.:
- </para>
- <programlisting language="php"><![CDATA[
- <!DOCTYPE html
- PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
- "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
- <html>
- <head>
- <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
- <?php echo $this->headTitle() ?>
- <?php echo $this->headScript() ?>
- <?php echo $this->headStyle() ?>
- </head>
- <body>
- <?php echo $this->render('header.phtml') ?>
- <div id="nav"><?php echo $this->placeholder('nav') ?></div>
- <div id="content"><?php echo $this->layout()->content ?></div>
- <?php echo $this->render('footer.phtml') ?>
- </body>
- </html>
- ]]></programlisting>
- </sect2>
- <sect2 id="zend.layout.quickstart.mvc">
- <title>Using Zend_Layout with the Zend Framework MVC</title>
- <para>
- <classname>Zend_Controller</classname> offers a rich set of functionality for
- extension via its <link linkend="zend.controller.plugins">front
- controller plugins</link> and <link
- linkend="zend.controller.actionhelpers">action controller
- helpers</link>. <classname>Zend_View</classname> also has <link
- linkend="zend.view.helpers">helpers</link>. <classname>Zend_Layout</classname>
- takes advantage of these various extension points when used with the
- <acronym>MVC</acronym> components.
- </para>
- <para>
- <methodname>Zend_Layout::startMvc()</methodname> creates an instance of
- <classname>Zend_Layout</classname> with any optional configuration you provide
- it. It then registers a front controller plugin that renders the
- layout with any application content once the dispatch loop is done,
- and registers an action helper to allow access to the layout object
- from your action controllers. Additionally, you may at any time grab
- the layout instance from within a view script using the
- <classname>Layout</classname> view helper.
- </para>
- <para>
- First, let's look at how to initialize <classname>Zend_Layout</classname> for use with
- the <acronym>MVC</acronym>:
- </para>
- <programlisting language="php"><![CDATA[
- // In your bootstrap:
- Zend_Layout::startMvc();
- ]]></programlisting>
- <para>
- <methodname>startMvc()</methodname> can take an optional array of options or
- <classname>Zend_Config</classname> object to customize the instance; these
- options are detailed in <link linkend="zend.layout.options">this section</link>.
- </para>
- <para>
- In an action controller, you may then access the layout instance as
- an action helper:
- </para>
- <programlisting language="php"><![CDATA[
- class FooController extends Zend_Controller_Action
- {
- public function barAction()
- {
- // disable layouts for this action:
- $this->_helper->layout->disableLayout();
- }
- public function bazAction()
- {
- // use different layout script with this action:
- $this->_helper->layout->setLayout('foobaz');
- };
- }
- ]]></programlisting>
- <para>
- In your view scripts, you can then access the layout object via the
- <classname>Layout</classname> view helper. This view helper is slightly
- different than others in that it takes no arguments, and returns an
- object instead of a string value. This allows you to immediately
- call methods on the layout object:
- </para>
- <programlisting language="php"><![CDATA[
- <?php $this->layout()->setLayout('foo'); // set alternate layout ?>
- ]]></programlisting>
- <para>
- At any time, you can fetch the <classname>Zend_Layout</classname> instance
- registered with the <acronym>MVC</acronym> via the
- <methodname>getMvcInstance()</methodname> static method:
- </para>
- <programlisting language="php"><![CDATA[
- // Returns null if startMvc() has not first been called
- $layout = Zend_Layout::getMvcInstance();
- ]]></programlisting>
- <para>
- Finally, <classname>Zend_Layout</classname>'s front controller plugin has one
- important feature in addition to rendering the layout: it retrieves
- all named segments from the response object and assigns them as
- layout variables, assigning the 'default' segment to the variable
- 'content'. This allows you to access your application content and
- render it in your view scripts.
- </para>
- <para>
- As an example, let's say your code first hits
- <methodname>FooController::indexAction()</methodname>, which renders some
- content to the default response segment, and then forwards to
- <methodname>NavController::menuAction()</methodname>, which renders content to
- the 'nav' response segment. Finally, you forward to
- <methodname>CommentController::fetchAction()</methodname> and fetch some
- comments, but render those to the default response segment as well
- (which appends content to that segment). Your view script could then
- render each separately:
- </para>
- <programlisting language="php"><![CDATA[
- <body>
- <!-- renders /nav/menu -->
- <div id="nav"><?php echo $this->layout()->nav ?></div>
- <!-- renders /foo/index + /comment/fetch -->
- <div id="content"><?php echo $this->layout()->content ?></div>
- </body>
- ]]></programlisting>
- <para>
- This feature is particularly useful when used in conjunction with
- the ActionStack <link linkend="zend.controller.actionhelpers.actionstack">action
- helper</link> and <link
- linkend="zend.controller.plugins.standard.actionstack">plugin</link>,
- which you can use to setup a stack of actions through
- which to loop, and thus create widgetized pages.
- </para>
- </sect2>
- <sect2 id="zend.layout.quickstart.standalone">
- <title>Using Zend_Layout as a Standalone Component</title>
- <para>
- As a standalone component, <classname>Zend_Layout</classname> does not offer nearly as
- many features or as much convenience as when used with the <acronym>MVC</acronym>.
- However, it still has two chief benefits:
- </para>
- <itemizedlist>
- <listitem><para>Scoping of layout variables.</para></listitem>
- <listitem>
- <para>Isolation of layout view script from other view scripts.</para>
- </listitem>
- </itemizedlist>
- <para>
- When used as a standalone component, simply instantiate the layout
- object, use the various accessors to set state, set variables as
- object properties, and render the layout:
- </para>
- <programlisting language="php"><![CDATA[
- $layout = new Zend_Layout();
- // Set a layout script path:
- $layout->setLayoutPath('/path/to/layouts');
- // set some variables:
- $layout->content = $content;
- $layout->nav = $nav;
- // choose a different layout script:
- $layout->setLayout('foo');
- // render final layout
- echo $layout->render();
- ]]></programlisting>
- </sect2>
- <sect2 id="zend.layout.quickstart.example">
- <title>Sample Layout</title>
- <para>
- Sometimes a picture is worth a thousand words. The following is a
- sample layout script showing how it might all come together.
- </para>
- <para>
- <inlinegraphic align="center" valign="middle"
- fileref="figures/zend.layout.quickstart.example.png" format="PNG" />
- </para>
- <para>
- The actual order of elements may vary, depending on the <acronym>CSS</acronym> you've
- setup; for instance, if you're using absolute positioning, you may
- be able to have the navigation displayed later in the document, but
- still show up at the top; the same could be said for the sidebar or
- header. The actual mechanics of pulling the content remain the same,
- however.
- </para>
- </sect2>
- </sect1>
- <!--
- vim:se ts=4 sw=4 et:
- -->
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