Title: Calling plugin function from another plugin
Last modified: August 31, 2016

---

# Calling plugin function from another plugin

 *  [Bushstar](https://wordpress.org/support/users/bushstar/)
 * (@bushstar)
 * [10 years, 3 months ago](https://wordpress.org/support/topic/calling-plugin-function-from-another-plugin/)
 * I need to get information from another plugin but I get an undefined variable
   error when trying to call the function from the object created in the first plugin.
   As far as I know plugins are loaded in alphabetical order from the active_plugins
   option. To help solve this I used a bit of code that changes the order so that
   the required plugin is at the front of active_plugins but the error persists.
 * My dev environment is PHPStorm which even allows me to click through from the
   second plugin to the first from the function call. This says to me that the first
   plugin object should be seen as long as the first plugin is loaded.
 * **Plugin A**
 *     ```
       class PluginA {
           public function check() {
               return 'checked';
           }
       }
   
       $example = new PluginA();
       ```
   
 * **PluginB**
 *     ```
       class PluginB {
           public function plugina_check() {
               // Check to see if plugin is active is true
               if (in_array('plugina/class-plugina.php', get_option('active_plugins')) {
                   // The next call throws Undefined variable $example
                   $result = $example->check();
               }
           }
       }
       ```
   

Viewing 2 replies - 1 through 2 (of 2 total)

 *  Thread Starter [Bushstar](https://wordpress.org/support/users/bushstar/)
 * (@bushstar)
 * [10 years, 3 months ago](https://wordpress.org/support/topic/calling-plugin-function-from-another-plugin/#post-7102813)
 * Actually, I have solved this but I am not sure it is best practice. In PluginB
   I have updated it to the following.
 *     ```
       class PluginB {
           public function plugina_check() {
               // Check to see if plugin is active is true
               if (in_array('plugina/class-plugina.php', get_option('active_plugins')) {
                   // Create mew object
                   $new_example = new PluginA();
   
                   // The next call throws Undefined variable $example
                   $result = $new_example->check();
               }
           }
       }
       ```
   
 * I assumed that the first objected created should be available to other plugins
   and that creating a second object would be unnecessary. I have now created two
   objects of the PluginA class.
 *  [catacaustic](https://wordpress.org/support/users/catacaustic/)
 * (@catacaustic)
 * [10 years, 3 months ago](https://wordpress.org/support/topic/calling-plugin-function-from-another-plugin/#post-7102940)
 * Asyou’ve seen, variable scope can be an issue for development. Any variables 
   that exist inside functions exist only in those functions, and you can’t access
   outsdie variable without them being passed in or made global.
 * If `$example` is set in the global scope you can also use this to access the 
   original value:
 *     ```
       class PluginB {
           public function plugina_check() {
               // Check to see if plugin is active is true
               if (in_array('plugina/class-plugina.php', get_option('active_plugins')) {
                   // Global value
                   global $example;
   
                   // The next call throws Undefined variable $example
                   $result = $example->check();
               }
           }
       }
       ```
   

Viewing 2 replies - 1 through 2 (of 2 total)

The topic ‘Calling plugin function from another plugin’ is closed to new replies.

## Tags

 * [undefined](https://wordpress.org/support/topic-tag/undefined/)

 * In: [Hacks](https://wordpress.org/support/forum/plugins-and-hacks/hacks/)
 * 2 replies
 * 2 participants
 * Last reply from: [catacaustic](https://wordpress.org/support/users/catacaustic/)
 * Last activity: [10 years, 3 months ago](https://wordpress.org/support/topic/calling-plugin-function-from-another-plugin/#post-7102940)
 * Status: not resolved

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