<p>Blocks are the boxes visible in the sidebar(s) of your web site. These are usually generated automatically by modules (e.g. recent forum topics), but you can also create your own blocks using either static HTML or dynamic PHP content.</p>
<p>The sidebar each block appears in depends on both which theme you're using (some are left-only, some right, some both), and on the settings in block management.</p><p>Whether a block is visible in the first place depends on four things:</p><ul><li>It must have its \"enabled\" box checked in block management.</li><li>If it has its \"custom\" box checked in block management, the user must have chosen to display it in their user preferences.</li><li>If the \"path\" field in block management is set, the visitor must be on a page that matches the path specification (more on this later).</li><li>If the block has its throttle box checked, the user will only see the block if the site throttle level is low.</li></ul>
<p>The block management screen also lets you specify the vertical sort-order of the blocks within a sidebar. You do this by assigning a <strong>weight</strong> to each block. Lighter blocks (smaller weight) \"float up\" towards the top of the sidebar. Heavier ones \"sink down\" towards the bottom of it.</p>
<p>The path setting lets you define the pages on which a specific block is visible. If you leave the path blank it will appear on all pages. The path uses a regular expression syntax so remember to escape special characters! The path expression is matched against the relative URL of a Drupal page, e.g. <code>book</code>, <code>node/12</code>, <code>admin</code>.</p>
<p>In case you do not know what a regular expression is, you should read about them in the PHP manual. The chapter to look at is the one on <a href=\"%pcre\">Perl-Compatible Regular Expressions (PCRE)</a>.</p>
<p>However, for basic tasks it is sufficient to look at the following examples:</p>
<p>If the block should only show up on blog pages, use <^blog>. To display on all node views use <^node>. The angular brackets are used as delimiters of the regular expression. To show up on either forum or book pages use <^(forum|book)>. The round brackets form a group of expressions, divided by the | character. It matches if any of the expressions in it match. A more complicated example is <^node/add/(story|blog|image)>. Blocks which have their paths set to this expression will show up on story, block, or image composition pages. If you want to show a block an all pages, but not the search page, use <^(?!search)>.</p>
<p>An administrator defined block contains HTML, text or PHP content supplied by you (as opposed to being generated automatically by a module). Each admin-defined block consists of a title, a description, and a body containing text, HTML, or PHP code which can be as long as you wish. The Drupal engine will 'render' the content of the block.</p>
<h4>PHP in admin-defined blocks</h4>
<p>If you know how to script in PHP, Drupal gives you the power to embed any script you like inside a block. It will be executed when the page is viewed and dynamically embedded into the page. This gives you amazing flexibility and power, but of course with that comes danger and insecurity if you don't write good code. If you are not familiar with PHP, SQL or with the site engine, avoid experimenting with PHP blocks because you can corrupt your database or render your site insecure or even unusable! If you don't plan to do fancy stuff with your blocks then you're probably better off with straight HTML.</p>
<p>Remember that the code within each PHP block must be valid PHP code - including things like correctly terminating statements with a semicolon so that the parser won't die. It is highly recommended that you develop your blocks separately using a simple test script on top of a test database before migrating to your production environment.</p>
<p>Notes:</p><ul><li>You can use global variables, such as configuration parameters, within the scope of a PHP box but remember that variables which have been given values in a PHP box will retain these values in the engine or module afterwards.</li><li>register_globals is now set to <strong>off</strong> by default. If you need form information you need to get it from the \"superglobals\" \$_POST, \$_GET, etc.</li><li>You should use the <code>return</code> statement to return the actual content for your block.</li></ul>
<blockquote><p>You want to have a box with the title \"Welcome\" that you use to greet your visitors. The content for this box could be created by going:</p>
<p>For more in-depth examples, we recommend that you check the existing boxes and use them as a starting point.</p>", array('%pcre' => 'http://php.net/pcre/'));
return t("Blocks are the boxes in the left- and right- side bars of the web site, depending on the chosen theme. They are made available active modules or created manually. The \"enabled\" checkbox sets the default status of the block. Only enabled blocks are shown. When the \"custom\" checkbox is checked, your users can show or hide the block using their account settings. In that case, the 'enabled' checkbox signifies the block's default status. You can assign the block's placement by giving it a region and a weight. The region specifies which side of the page the block is on, and the weight sorts blocks within a region. Lighter (smaller weight value) blocks \"float up\" towards the top of the page. The path setting lets you define which pages you want a block to be shown on. Blocks can automatically be temporarily disabled to reduce server load when your site becomes extremely busy by checking throttle. The auto-throttle functionality must be enabled on the <a href=\"%throttle\">throttle configuration page</a> after having enabled the throttle module.", array('%throttle' => url('admin/settings/throttle')));
return t("Here you can create a new block. Once you have created this block you must make it active and give it a place on the page using <a href=\"%overview\">blocks</a>. The title is used when displaying the block. The description is used in the \"block\" column on the <a href=\"%overview\">blocks</a> page. If you are going to place PHP code in the block, and you have the <em>create php content</em> permission (see the <a href=\"%permission\">permissions</a> page), you <em>must</em> change the type to PHP to make your code active.", array('%overview' => url('admin/block'), '%permission' => url('admin/user/configure/permission')));
$group = form_textfield(t('Block title'), 'title', $edit['title'], 50, 64, t('The title of the block as shown to the user.'));
$group .= form_textarea(t('Block body'), 'body', $edit['body'], 70, 10, t('The content of the block as shown to the user.'));
$group .= form_textfield(t('Block description'), 'info', $edit['info'], 50, 64, t('A brief description of your block. Used on the <a href="%overview">block overview page</a>.', array('%overview' => url('admin/block'))));
$group .= form_radios(t('Block type'), 'type', $edit['type'], $type, t("If you would like to use PHP code inside your block, set the above option to 'PHP' instead of 'HTML'."));
db_query("UPDATE {boxes} SET title = '%s', body = '%s', info = '%s', type = %d WHERE bid = %d", $edit['title'], $edit['body'], $edit['info'], $edit['type'], $edit['bid']);
