Nashwan D

Conditional Themes is an API to switch the themes on certain conditions.
<h4>Usage</h4>
Write an another plugin file and use the Conditional Themes API as the example below:
<pre><code>add_action('plugins_loaded', 'my_conditional_themes_setup', 100);

function my_conditional_themes_setup()
{
 // Switch to Twenty Eleven theme if the visitor use Internet Explorer.
 Conditional_Themes_Manager::register('twentyeleven', function() {
 global $is_IE;
 return (bool) $is_IE;
 });

 // Switch to Twenty Thirteen theme if the user has administrator role.
 Conditional_Themes_Manager::register('twentythirteen', function() {
 return current_user_can('administrator');
 });

 // Switch to a custom theme if the visitor use a mobile device.
 Conditional_Themes_Manager::register('mobile', 'wp_is_mobile');
}
</code></pre>
Another example, With enabling persistent mode.
<pre><code>add_action('plugins_loaded', 'my_conditional_themes_setup', 100);

function my_conditional_themes_setup()
{
 // Enable the switcher persistent mode.
 Conditional_Themes_Manager::set_option('persistent', true);

 // Switch to Twenty Sixteen theme when we being on 2016.
 Conditional_Themes_Manager::register('twentysixteen', function() {
 return (date('Y') == 2016);
 });

 // Switch to Twenty Fifteen theme when the site reaches 500 post.
 Conditional_Themes_Manager::register('twentyfifteen', function() {
 return ((int) wp_count_posts() > 500);
 });
}
</code></pre>
Note: You can use <a href="https://wordpress.org/plugins/code-snippets" rel="ugc">Code Snippets</a> plugin to add the code snippets to your site.
<h4>Contributing</h4>
Developers can contribute to the source code on the <a href="https://github.com/nash-ye/WP-Conditional-Themes" rel="nofollow ugc">Github Repository</a>.

Conditional Themes

Keep up the good work. Plugin exactly doing what it should do. Perfect :)

Awesome Plugin. Neat and Accurate

A simple API to switch the themes on certain conditions.

yorksupport

York IE – Theme Switcher lets editors assign a theme to a single piece of content or preview how that content looks in another installed theme. The site-wide active theme stays unchanged.
Features
<ul>
<li>Assign a theme per post, page, or public custom post type</li>
<li>Settings page to enable theme switching per post type</li>
<li>Preview any supported item with another installed theme in a new tab</li>
<li>Content Theme meta box in the editor sidebar</li>
<li>Front-end admin bar menu for quick theme previews while logged in</li>
<li>Preview banner with an exit link when previewing</li>
<li>Works with subdirectory WordPress installs</li>
</ul>
How it works
<ol>
<li>Edit a post, page, or custom post type.</li>
<li>Choose a theme from the Content Theme sidebar panel.</li>
<li>Click Update to save the assignment, or use Preview with selected theme to test without saving.</li>
</ol>
Visitors see the assigned theme only on that content item. Other pages continue using the active site theme.
Permissions
<ul>
<li>Theme preview URLs require a valid nonce and permission to edit the item or the <code>switch_themes</code> capability.</li>
<li>Assigned themes are visible to all visitors on the front end for that content item.</li>
</ul>
Developer filters
<ul>
<li><code>pagethsw_supported_post_types</code> — Limit or extend supported post types.</li>
<li><code>pagethsw_is_supported_post_early</code> — Control post type support before <code>init</code>.</li>
</ul>

York IE – Theme Switcher

Assign or preview a different installed theme on individual posts, pages, and custom post types without changing the site-wide active theme.

Conditional Themes vs York IE – Theme Switcher