Plugin base URL

Question

In a question that is related to, but not the same as, How to link to images in my plugin regardless of the plugin folder's name

• plugin-folder/plugin-main-file.php
• plugin-folder/images/ containing all images
• plugin-folder/classes/ containing class definitions
• plugin-folder/classes/class1-files containing additional files for class 1
• plugin-folder/classes/class2-files containing additional files for class 2
• etc

To access images, I can use relative addressing, such as plugins_url( '../images/image.png', dirname( __FILE__ ) ) but this requires a knowledge of the file structure, and a level of hard-coding that leads to potential maintenance issues.

Alternatively, I can define a global constant (eg) define('PLUGIN_ROOT', basename(dirname(__FILE__)) . '/' . basename(__FILE__)); in my main-file.

Ideally, there is a Wordpress function that would give me the plugin base name, from anywhere in my plugin (ie always return /plugin-folder/)... but I haven't found one. Is there such a beastie?

-- EDIT TO ADD --

I am also aware of plugins_url() with no parameters... but this returns http://mydomain.ext/wp-content/plugins - ie without my plugin name!

Answer 1

I think you are looking for plugin_dir_url:

$url = plugin_dir_url(__FILE__);

$imageurl = $url.'images/someimage.png';

EDIT: Sorry I misread the question... that is only an answer to the linked question. You could check the parent directory recursively until you find the right one:

function base_plugin_dir($dirpath) {
    if (substr(dirname($dir),-7) == 'plugins') {return $dirpath;}
    else {$dirpath = base_plugin_dir($dirpath);}
    return $dirpath;
}

function base_plugin_dir_url($filepath) {
    $baseplugindir = base_plugin_dir(dirname($filepath));
    $url = plugin_dir_url(trailingslashit($baseplugindir));
    return $url;
}

Then you can get the URL using that function from whatever file:

$basepluginurl = base_plugin_dir_url(__FILE__);
$imageurl = $basepluginurl.'/images/wordpress.png';

OR

Better yet just set a constant from your main plugin file to use it later:

$url = plugin_dir_url(__FILE__);
define('MY_UNIQUE_PLUGIN_URL',$url);

So as to use in say /plugin/my-plugin/class/class1.php

$imageurl = MY_UNIQUE_PLUGIN_URL.'/images/wordpress.png';

Answer 2

Sorry for the late answer, below is the function I use to retrieve the plugin directory name in the format requested by @Andrew (i.e. with a trailing slash as mentioned in the comment to Kevin)

/**
 * Retrieve the Plugin Directory 
 * 
 * Returns the root directory for current plugin with a trailing slash
 */
function current_plugin_dir() {
  $base = plugin_basename( __FILE__ );
  $slash = strpos($base,'/');
  $plugin_dir = $loc? substr( $base, 0, $loc + 1): $base;
  return $plugin_dir;
}

To remove the slash just leave out the '+ 1' in the $plugin_dir line.

Answer 3

Edit

My bad, in that case I can think of this.

$x = WP_PLUGIN_URL.'/'.str_replace(basename( __FILE__),"",plugin_basename(__FILE__));

It should return

http://[url-path-to-plugins]/[custom-plugin]/

But straight forward class I don't think wordpress has one

---

Yes it is

from https://codex.wordpress.org/Function_Reference/plugin_basename

$x = plugin_basename( __FILE__ );

Answer 4

plugin_basename may be what you want. If your plugin file is located at /wp-content/plugins/my-plugin/my-plugin.php this would return:

$file = plugin_basename( __FILE__ ); // "my-plugin/my-plugin.php"

If you called the same thing from a sub-directory in your plugin, such as /wp-content/plugins/my-plugin/inc/my-plugin-include.php it would return:

my-plugin/inc/my-plugin-include.php

If you want the current root directory for a plugin, then this custom function should do the trick:

/**
 * Current Plugin Directory 
 * 
 * Returns the root directory for current plugin
 */
function current_plugin_dir() {
    $basename = plugin_basename( __FILE__ );

    return str_replace( __FILE__, '', $basename );
}