My guess is you get a PHP error, which generates output before the headers are sent. If you have E_NOTICE enabled, calling $_POST[‘foo’] may generate a “Notice: undefined variable” error if that variable is not set. Best practice: never assume anything about GET, POST, COOKIE and REQUEST variables. Always check first using isset() or empty(). … Read more
This function and activation hook prevents the plugin from activating and allows you to check for both a minimum PHP and WordPress version. register_activation_hook( __FILE__, array( ‘Your_Plugin_Class_Name’, ‘activate’ ) ); /** * Plugin Activation hook function to check for Minimum PHP and WordPress versions * @param string $wp Minimum version of WordPress required for this … Read more
Necessary API Functions/Methods: You’ll need WP_Screen::is_block_editor() method to check if you are currently in the Gutenberg Editor (Since WordPress 5.0). Also, if you install Gutenberg as a separate plugin, then you’ll have the is_gutenberg_page() function available to do the same check. So for an overall solution, you’ll need to combine these two. Of course, this … Read more
As far WordPress is concerned – your multi-dimensional array is one option. To update just part of the multi-dimensional array its necessary to retrieve the entire array, alter it accordingly and then update the entire array. Suppose your multi-dimensional array is as follows: my_options = array( ‘option_a’=>’value_a’, ‘option_b’=>’value_b’, ‘inner_array’=>array( ‘foo’ => ‘bar’, ‘hello’ => ‘world’, … Read more
As the error says you need an instance of the class to use $this. There are at least three possibilities: Make everything static class My_Plugin { private static $var=”foo”; static function foo() { return self::$var; // never echo or print in a shortcode! } } add_shortcode( ‘baztag’, array( ‘My_Plugin’, ‘foo’ ) ); But that’s not … Read more
There is no index because the need for it was never strong enough. In ticket #14258 it was suggested, but since most options use autoload=yes by default, the index would be ignored anyway. There is also the still open ticket #24044 _Add index to wp_options to aid/improve performance_. I think you should create an index. … Read more
First rule of thumb: do not deregister core-bundled scripts and replace with other versions, unless you are absolutely certain that no Theme, Plugins, or core itself will break due to the version change. Really, unless you absolutely need an alternate version of a core-bundled script, just use what is bundled with core. Second, I strongly … Read more
I don’t think an action has been added. You can look at version details for any version and see any new actions added. The WordPress Way to run code on plugin update is what is described here: The proper way to handle an upgrade path is to only run an upgrade procedure when you need … Read more
wp-includes contains everything needed to run WordPress via the frontend ( and then some ). It is the territory of WordPress Core, and as the adage goes, never modify core under any circumstances. While wp-content may define plugins and themes, the API itself and the vast majority of the WordPress core sits in that folder. … Read more
Here is a modified checklist, based on my current (work-in-progress) settings/data security checklist used for reviewing Themes (the principles should be no different for Plugins than they are for Themes): Plugins should prefix all options, custom functions, custom variables, and custom constants with plugin-slug. Plugins should implement Plugin Options and Plugin Settings pages deliberately, rather … Read more