Karrde

Includes a file’s contents in the widget. Quick and dirty, all this does is use the PHP include function to include the specified file in the widget. There is NO checking done whatsoever on the file, so use it at your own risk. I wrote this because I couldn’t find a widget to do this ? plugins exist for using include in posts and pages, but not in widgets.

Include Widget

Includes a file's contents in the widget.

gqevu6bsiz

This plugin allows you to include extra JavaScript or CSS files in your WordPress page.
You can:
<ul>
<li>Include as many as you like.</li>
<li>Choose whether files are to be included on the front-end or the back-end.</li>
<li>Choose where to include them in the header or the footer.</li>
<li>Choose conditions to use for inclusion (logged-in users only, admin users only, front page only).</li>
<li>Choose conditions of you can add.</li>
</ul>
Please if you want to add conditions. 
For example add filter:
<pre><code>add_filter( 'jcim_condition' , 'my_conditions' );
function my_conditions( ) {
 $conditions = array(
 array(
 "code" => "current_user_can",
 "val" => "edit_themes",
 "desc" => "Only edit theme role have user",
 "help_link" => "https://codex.wordpress.org/Function_Reference/current_user_can"
 ),
 array(
 "code" => "is_admin",
 "val" => "",
 "desc" => "Only admin screen",
 "help_link" => ""
 ),
 );
 return $conditions;
}
</code></pre>
<h3>日本語でのご説明</h3>
このプラグインは、よくごちゃごちゃになってしまうjavascriptファイルの読み込みとcssファイルの読み込みを、 
管理画面だけ、またはサイトだけに読み込むファイルを、１箇所で管理するためのプラグインです。 
サイトで何のファイルを読み込んでいるのか、すっきり。

Js Css Include Manager

This plug-in is a will clean the file management. You can only manage the screen. You can also only site the screen.

Include Widget vs Js Css Include Manager