Function: Determines if a post exists based on title, content, date and type.

Function: Creates a new post from the “Write Post” form using `$_POST` information.

Function: Calls wp_write_post() and handles the errors.

Function: Adds post meta data defined in the `$_POST` superglobal for a post with given ID.

Function: Deletes post meta data by meta ID.

Function: Renames `$_POST` data from form names to DB post columns.

Function: Returns only allowed post data fields.

Function: Updates an existing post with values provided in `$_POST`.

Function: Processes the post data for the bulk editing of posts.