repo_zf1/documentation/manual/en/tutorials/paginator-simple.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- Reviewed: no -->
<sect1 id="learning.paginator.simple">
    <title>Simple Examples</title>

    <para>
        In this first example we won't do anything spectacular, but hopefully it will
        give you a good idea of what Zend_Paginator is designed to do.
        Let's say we have an array called $data with the numbers 1 to 100 in it, which
        we want to divide over a number of pages. We can use the static <methodname>factory()</methodname>
        method in the <classname>Zend_Paginator</classname> class to get a <classname>Zend_Paginator</classname>
        object with our array in it.
    </para>

    <programlisting language="php"><![CDATA[
// Create an array with numbers 1 to 100
$data = range(1, 100);

// Get a Paginator object using Zend_Paginator's built-in factory.
$paginator = Zend_Paginator::factory($data);
]]></programlisting>

    <para>
        We're already almost done! The $paginator variable now contains a reference to the
        Paginator object. By default it is setup to display 10 items per page.
        To display the items for the currently active page, all you need to do is iterate
        over the Paginator object with a foreach loop. The currently active page defaults
        to the first page if it's not explicitly specified. We will see how you can select
        a specific page later on. The snippet below will display an unordered list containing the
        numbers 1 to 10, which are the numbers on the first page.
    </para>

    <programlisting language="php"><![CDATA[
// Create an array with numbers 1 to 100
$data = range(1, 100);

// Get a Paginator object using Zend_Paginator's built-in factory.
$paginator = Zend_Paginator::factory($data);

?><ul><?php

// Render each item for the current page in a list-item
foreach ($paginator as $item) {
    echo '<li>' . $item . '</li>';
}

?></ul>
]]></programlisting>

    <para>
        Now let's try and render the items on the second page. You can use the
        <methodname>setCurrentPageNumber()</methodname> method to select which page you want to view.
    </para>

    <programlisting language="php"><![CDATA[
// Create an array with numbers 1 to 100
$data = range(1, 100);

// Get a Paginator object using Zend_Paginator's built-in factory.
$paginator = Zend_Paginator::factory($data);

// Select the second page
$paginator->setCurrentPageNumber(2);

?><ul><?php

// Render each item for the current page in a list-item
foreach ($paginator as $item) {
    echo '<li>' . $item . '</li>';
}

?></ul>
]]></programlisting>

    <para>
        As expected, this little snippet will render an unordered list with the numbers
        11 to 20 in it.
    </para>

    <para>
        These simple examples demonstrate a small portion of what can be achieved with
        <classname>Zend_Paginator</classname>. However, a real application rarely reads its data from a plain
        array, so the next section is dedicated to showing you how you can use Paginator
        to paginate the results of a database query. Before reading on, make sure you're familiar with
        the way <classname>Zend_Db_Select</classname> works!
    </para>

    <para>
        In the database examples we will look at a table with blog posts called 'posts'.
        The 'posts' table has four columns: id, title, body, date_created.
        Let's dive right in and have a look at a simple example.
    </para>

    <programlisting language="php"><![CDATA[
// Create a select query. $db is a Zend_Db_Adapter object, which we assume
// already exists in your script.
$select = $db->select()->from('posts')->order('date_created DESC');

// Get a Paginator object using Zend_Paginator's built-in factory.
$paginator = Zend_Paginator::factory($select);

// Select the second page
$paginator->setCurrentPageNumber(2);

?><ul><?php

// Render each the title of each post for the current page in a list-item
foreach ($paginator as $item) {
    echo '<li>' . $item->title . '</li>';
}

?></ul>
]]></programlisting>

    <para>
        As you can see, this example is not that different from the previous one.
        The only difference is that you pass a <classname>Zend_Db_Select</classname> object to the
        Paginator's <methodname>factory()</methodname> method, rather than an array.
        For more details on how the database adapter makes sure that your query
        is being executed efficiently, see the Zend_Paginator chapter in the reference manual
        on the DbSelect and DbTableSelect adapters.
    </para>

</sect1>