Easily assign categories to media with a clean, simple, and searchable category meta box. Then use the gallery shortcode to display category galleries

Eddie Moya

<p>Allows users to assign categories (or other taxonomy terms) to items in their Media Library with a clean and simplified, searchable version of the standard category meta box.<br />
The “Search Categories” field allows you to narrow your search for a category as you type – this functionality is not native to WordPress but is instead borrowed from Jason Corradino’s<br />
<a href="https://wordpress.org/extend/plugins/searchable-categories/" rel="ugc">Searchable Categories</a> plugin. If you would like to enable this feature for your posts<br />
<a href="https://wordpress.org/extend/plugins/searchable-categories/" rel="ugc">download his plugin here</a></p>
<p>Since WordPress 3.5 now supports attachment taxonomy, the work of adding a metabox to the attachment editor is happening entirely inside of WordPress. This is great, and we now have true metaboxes for taxonomy – they core team has also accepted my patches which caused several headaches for this plugin. Media Categories 1.5 takes advantage of the new Media Modal – with this plugin, you can now edit a images categories directly from the modal screen. I’ve also fixed some long standing bugs with the shortcode gallery functionality.</p>
<h4>Updates</h4>
<ul>
<li>Since version 1.5 : Supports the new WordPress 3.5 by adding the metabox to the new Media Modal. Also fixed bugs in the gallery shorcode behavior. All while still supporting 3.3.x – 3.4.x</li>
<li>Since version 1.4 : This plugin allows for <strong>multiple metaboxes</strong> to be created for any number of taxonomies.</li>
<li>Since version 1.3 : A <strong>filter</strong> has been added to allow developers to modify which taxonomy is being used. See ‘Other Notes’ > ‘Taxonomy Filter Usage’ for details</li>
<li>Since version 1.2 : This plugin extends the native <strong>[gallery] shortcode</strong> of WordPress so that it has a ‘category’ parameter. See the “Shortcode Usage” under “Other Notes” for more details.</li>
</ul>
<h3>Shortcode Usage</h3>
<h4>Normal Shortcode Usage</h4>
<p>This plugin takes advantage of the existing <code>[gallery]</code> shortcode for showing images by adding the <code>'category'</code> parameter.<br />
The value passed to the <code>'category'</code> parameter can be either the <code>category</code> <code>slug</code>, or the <code>term_id</code>.</p>
<pre><code>[gallery category="my-category-slug"]
OR
[gallery category="12"]
</code></pre>
<p>Its important to note that when passing the <code>'category'</code> parameter, the <code>[gallery]</code> shortcode will by default <strong>ignore the current post<br />
and simply try to include all images from the category</strong>. The syntax above will retrieve any images that are assigned<br />
to <code>'my-category-slug'</code> a.k.a term id <code>#12</code>, regardless of whether or not those images are attached to the current post.</p>
<p>To query within a post (even the current post), you’ll need to explicitly add the post id as such…</p>
<pre><code>[gallery category="my-category-slug" id="43"]
</code></pre>
<p>This shortcode will retrieve any images attached to post <code>#43</code> that are categorized as <code>'my-slug-category'</code>.</p>
<p>Aside from this behavior, the [gallery] shortcode should behave exactly as it does by default with the built-in shortcode.<br />
The <code>id</code> parameter will behave as normal when the <code>category</code> parameter is not invoked.<br />
For more information on using the built-in <a href="https://codex.wordpress.org/Gallery_Shortcode" rel="nofollow ugc">gallery shortcode checkout the codex page</a>.</p>
<h4>Other Taxonomy Shortcode Usage</h4>
<p>If a developer implementing this plugin has made use of the <code>mc_taxonomy</code> filter to modify which taxonomy<br />
this plugin uses for attachments, then the name of that particular taxonomy will need to be used in place of <code>category</code><br />
as the shortcode parameter. For example, if you applied ‘Post Tags’ to your images then users should use the <code>post_tag</code> parameter<br />
in the Gallery Shortcode.</p>
<pre><code>[gallery post_tag="my-tag-slug"]
OR
[gallery post_tag="12"]
</code></pre>
<p><em>[Warning: nerdy developer stuff ahead]</em></p>
<h3>Multiple Taxonomy Metaboxes  *NEW!*</h3>
<p>Since 1.4 this plugin allows developers to create metaboxes for any number of taxonomies. While previous the previous version allowed<br />
developers to change the taxonomy being used, it still only allowed a single taxonomy metabox to be generated. With 1.4, that has changed.</p>
<p>All a developer needs to do, is create a new instance of the Media_Categories class and pass their desired taxonomy as an argument.</p>
<pre><code>$my_custom_media_metabox = new Media_Categories('my_custom_taxonomy');
</code></pre>
<p>Thats it!, nothing else to it, the plugin will take care of the rest. You can create as many instances as you like – just make sure to be careful<br />
when doing this in conjunction with the <code>mc_taxonomy</code> filter – always check the current taxonomy.</p>
<p>Obviously this works with any taxonomy, including built-in taxonomies such as ‘post_tag’, ‘link_categories’,<br />
and yes, even ‘nav_menu’. I’ll leave it to you developers out uses for that.</p>
<h3>Taxonomy Filter Usage: ‘mc_taxonomy’</h3>
<p><strong>Note</strong>: Since 1.4, this plugin allows developers to generate any number of metaboxes, for any number of different taxonomies. Because of this,<br />
it is important that when filtering the taxonomy, developers conditionally check the current taxonomy before returning a different – otherwise<br />
the filter would override <em>all</em> instances of the plugin’s metaboxes with the same taxonomy. The examples below have been changes accordingly</p>
<p>Since version 1.3, the Media Categories plugin includes a filter allowing developers to modify the taxonomy being used.<br />
Changing the taxonomy will automatically change all the labels used around the metabox, and change the way the Gallery Shortcode<br />
works so that it accommodates whatever taxonomy has been chosen.</p>
<p>The tag for this filter is <code>'mc_taxonomy'</code>, and usage could not be simpler.</p>
<pre><code>add_filter('mc_taxonomy', 'mc_filter_taxonomy');

function mc_filter_taxonomy($taxonomy){

    if($taxonomy == 'category'){
        $taxonomy = 'post_tag';
    }

    return $taxonomy
}
</code></pre>
<p>The above code will swap out all references to ‘category’ with appropriate (properly pluralized) references to the ‘post_tag’ taxonomy.</p>
<p>It will also change the way the Gallery Shortcode works to use your chosen taxonomy.</p>
<h4>Important (potential gotchas)</h4>
<ul>
<li>The <code>category</code> parameter for the Gallery Shortcode will be changed by using this filter, so that instead of <code>category</code> is will by <code>your_taxonomy</code>. In the case above with tags,<br />
you would write a shortcode as such. <code>[gallery post_tag="my-tag"]</code> OR <code>[gallery post_tag="43"]</code>.</li>
<li>If using a Custom Taxonomy with this plugin, be sure to assign values to the labels for proper pluralization and context</li>
</ul>
<h3>Related Plugin</h3>
<p>Checkout this great plugin for Searchable Categories by Jason Corradino, whose javascript I use in this plugin.<br />
I believe this very simple functionality should be a part of the standard categories metabox in core.<br />
While I do not employ the plugin directly, the javascript used for filtering/searching is in fact derived with<br />
consent, and a few modifications from that plugin. To enable this feature on all your category metaboxes, install the<br />
<a href="https://wordpress.org/extend/plugins/searchable-categories/" rel="ugc">Searchable Categories</a> plugin.</p>
<ul>
<li><a href="https://wordpress.org/extend/plugins/searchable-categories/" rel="ugc">Searchable Categories</a> by Jason Corradino</li>
</ul>


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