Added function to retrieve filterable post statuses for classification.

[jamesmorrison]

Description of the Change

Adds a filter to allow post statuses other than publish to be allowed to classify content.

Benefits

Users will be able to save content in other post statuses - e.g. draft and this content will be classified.

Possible Drawbacks

If publish is removed from the array, content will not be classified on publication.

Verification Process

I ran the following code in a MU plugin to modify the post statuses:

add_action(
	'after_setup_theme',
	function() {
		add_filter(
			'classifai_post_statuses_for_post_type_or_id',
			function( $post_statuses, $post_type, $post_id ) {
				return array(
					'publish',
					'draft',
					'future',
				);
			},
			10,
			3
		);
	}
);

The resulting data upon saving a draft post was:

{"post_statuses":["publish","draft","future"],"post_status":"draft","post_type":"post","post_id":2285}

Checklist:

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests passed.

Applicable Issues

#309

Changelog Entry

Added: classifai_post_statuses filter; allows post statuses for content classification to be changed as required (but would apply to all post types).

Added: classifai_post_statuses_for_post_type_or_id filter; allows post statuses for content classification to be changed as required based on post type / post ID.