It is common for scripts to perform some "pre-flight" tests at runtime to ensure that they can execute correctly. Common examples of these types of tests include checking the version of PHP or of WordPress. To avoid any potential catastrophes that could occur if our plugin is activated on incompatible WordPress versions, we will perform a simple WordPress version check, and you can use this format as a guideline for how you might perform similar pre-flight tests. Let's add another PHP constant to define the minimum version of WordPress required. We want this plugin to require WordPress version 3 or greater:
define('DIGGTHIS_MIN_WORDPRESS_VERSION', '3.0');Again, we place this near the top of our plugin in the area we allotted for configuration and settings.
In order to check the current version of WordPress, we can use the global WordPress variable $wp_version. We can then use the PHP function version_compare()
to compare the current version with the minimum required...