Next and/or previous post content

by

Take a look at the get_adjacent_post function.

It takes three paramters, all of which are optional:

  • a boolean, whether the post should be from the same category
  • a string of category IDs that should be excluded
  • a boolean, whether the previous (true) or next (false) post should be retrieved.

Hence the previous post, regardless of category can be retrieved via

$prev_post = get_adjacent_post( false, '', true );

and the next via

$next_post = get_adjacent_post( false, '', false );

If successful, the function will return a complete post object, hence:

echo $prev_post->post_excerpt;

should do.