Related Links

Related Links gives you the possibility to manually link other posts to your current post. But you can also link pages, media or any custom post-type. And in addition you can use custom urls to link to external files. The plugin adds a Metabox to the writing page with a list of all available content.

Features:

• Shows a list of all available content in a Metabox on the writing page
• Multiple links can be selected
• Link order can be changed through drag and drop
• Custom URLs can be added
• Search field to quickly find a link
• Simple theme integration with an included widget or related_links()
• Works with custom post-types
• Settings to enable the post-types that should be shown in the Metabox

1. Upload the related-links folder to the /wp-content/plugins/ directory.
2. Activate the plugin through the Plugins menu in WordPress.
3. Set in the link types in Related Links under the Settings menu in WordPress.
4. Place <?php related_links(); ?> in your templates.

How do I show the links in my theme?

Use the Related Links widget to show a list of the related links.

How do I show the links in a specific template?

Use the related_links() function directly in your template files. This will return an unordered list with an <ul> wrapper. Use this code for example in your `content.php’ template:

<?php related_links(); ?>

How can I modify the output of the link list?

You need to use the get_related_links() function. A simple example that shows a list with all link names and the type of link:

<?php $related_links = get_related_links(); ?>
<ul>
    <?php foreach ($related_links as $link): ?>
        <li><a href="<?php echo $link['url']; ?>"><?php echo $link['type']; ?>: <?php echo $link['title']; ?></a></li>
    <?php endforeach; ?>
</ul>

What are the properties returned by the `get_related_links()` function?

The get_related_links() returns an array containing every related link. when you loop through this array every link consists of another array with the following keys:

• key id: equals to $post->ID or null for custom links
• key url: equals to get_permalink() or the manually entered url of a custom link
• key title: equals to $post->post_title or the manually entered title of a custom link
• key type: the $post->post_type or null for custom links

How do I only show the links for a certain post_type in my theme?

Set the $post_type in get_related_links($post_type) to 'post', 'page' or any custom post-type. A simple example that show a list of links:

<?php $related_links = get_related_links('page'); ?>
<ul>
    <?php foreach ($related_links as $link): ?>
        <li><a href="<?php echo $link['url']; ?>"><?php echo $link['type']; ?>: <?php echo $link['title']; ?></a></li>
    <?php endforeach; ?>
</ul>

How do I show the related links of another post (not the current one)?

Set the $post_id in get_related_links(null, $post_id) to the id of the post. A simple example that show a list of links:

<?php $related_links = get_related_links(null, 1); ?>
<ul>
    <?php foreach ($related_links as $link): ?>
        <li><a href="<?php echo $link['url']; ?>"><?php echo $link['type']; ?>: <?php echo $link['title']; ?></a></li>
    <?php endforeach; ?>
</ul>

How do I link directly to a media file?

You need to check the 'type' and then get with wp_get_attachment_url() the attachment url from the 'id'.

<?php $related_links = get_related_links(null, 1); ?>
<ul>
<?php foreach ($related_links as $link): ?>
    <?php if ($link['type'] == 'attachment') :
        $url = wp_get_attachment_url($link['id']);
    else :
        $url = $link['url'];
    endif; ?>
    <li><a href="<?php echo $url; ?>"><?php echo $link['title']; ?></a></li>
<?php endforeach; ?>
</ul>

How do show the type of a media file?

You need to check the 'type' and then get with wp_get_attachment_url() the attachment url from the 'id'.

<?php $related_links = get_related_links(null, 1); ?>
<ul>
<?php foreach ($related_links as $link): ?>
    <?php 
    if ($link['type'] == 'attachment') :
        $url = wp_get_attachment_url($link['id']);
        $mime = explode('/', get_post_mime_type($link['id']));
        $mime = $mime[sizeof($mime) - 1];           
    else :
        $url = $link['url'];
        $mime = null;
    endif; 
    ?>
    <li><a href="<?php echo $url; ?>"><?php echo $link['title']; ?><?php echo isset($mime) ? ' (' . $mime . ')' : ''; ?></a></li>
<?php endforeach; ?>
</ul>

How to prevent a PHP error when the plugin is not activated?

Put the get_related_links() function or your whole code into an if clause. Like this your theme will still work even if the plugin is deactivated.

<?php if(function_exists('get_related_links')) : ?>
    <?php $related_links = get_related_links(); ?>
    <ul>
        <?php foreach ($related_links as $link): ?>
            <li><a href="<?php echo $link['url']; ?>"><?php echo $link['type']; ?>: <?php echo $link['title']; ?></a></li>
        <?php endforeach; ?>
    </ul>
<?php endif; ?>

1. 

   Related links Metabox on the post page.

2. 

   Settings page.

1.7.1

• Removed an obsolete console log that may cause problems on Internet Explorer 7 and 8.

1.7

• Added a Widget to show the related links in your widgetized theme areas.
• Fixed a JavaScript error when adding custom links.
• Settings aren’t reset after plugin reactivation.

1.6

• Metabox loads new list items while scrolling. Leads to a better load and search performance when a blog contains many hundred posts.
• Use placeholder attribute for input fields.
• Use plugins_url() to load stylesheets and javascript.
• Enqueue jQuery UI correctly.

1.5.7

• Added related_links() function to echo an unordered list of links
• Added media post-type to link to media files (thanks jhned)

1.5.6

• Fixed a problem where empty post data could lead to a php error

1.5.5

• Fixed the marking of already selected links in the list (thanks robert_k for the fix)

1.5.4

• Fixed a bug where get_related_links() always returned custom links when the post_type parameter was set

1.5.3

• Updated CSS for WordPress 3.3

1.5.2

• Updated the way how settings are saved to be compatible with future WordPress versions

1.5.1

• Fixed a bug where the plugin was also loaded on the taxonomy admin pages

1.5

• Links order can be changed with drag and drop
• Search field to quickly find a link by name
• External URLs can be added
• Added an id property to the get_related_links() function
• New meta data structure but legacy support for older plugin versions is added
• Checking if the post really exists before it is added to the output
• Better list loading through ajax

1.0.1

• The meta box content list is now scrollable

1.0

Initial release