There is (often) a get_<echo_or_print_function> even if the WordPress Codex doesn’t say so (or something really similar).

Situation:

You want to style the next_posts_link() and previous_post_links() in such a way that requires a container/wrapper div. Unfortunately two functions echo (display) their output so you cannot perform a conditional operation on them in PHP. So your container div (and it’s styling) appear regardless of whether there are more posts or not.

WordPress functions such as blog_info() do the same thing but also offer a “get_” version which returns the value instead e.g. get_blog_info().

You check the WordPress Codex for get_next_posts_link() but it does not seem to exist.

Solution:

Try get_next_posts_link() anyway because it does exist.

In reality if there is a function that ONLY echoes or prints it’s value it probably always maybe does. In fact after further review of the WordPress source files if a function echoes its output then it probably always maybe calling the get_version itself (found in wp-includes/link-template.php):

/**
* Display the next posts pages link.
*
* @since 0.71
* @uses get_next_posts_link()
*
* @param string $label Content for link text.
* @param int $max_page Optional. Max pages.
*/
function next_posts_link( $label = 'Next Page »', $max_page = 0 ) {
    echo get_next_posts_link( $label, $max_page );
}

Despite the fact that the Codex says many pages are incomplete and that many existing links to function references 404 I still treat the Codex like gospel. It’s a shame that the documentation isn’t more thorough, but I guess that is where we are supposed to be giving back to the community. I’m posting this here as a general tip and mainly for a reminder for myself that Codex is far from complete and that a quick search of the WordPress source can do wonders for the health and cleanliness of your own WordPress PHP code.

In some cases there is not an exact “get_function” that will work. For next/previous post links, next_post_link() and previous_post_link() you actually need get_next_post() and get_previous_post() all of which use adjacent_post_link() to return the values echoed or not.

In my case the problem came up while making an older/newer posts widget that allowed for CSS buttons to be cleanly displayed in the widgetized sidebar. I spent 15 minutes trying to figure out a workaround (after I checked the Codex) before remembering the “get_” functions. I blame the heat. The atypical cool weather here in San Diego has ended and the much more realistic July heat has returned and my brain is turning off.

UPDATE: While I don’t have the time to properly add the new pages to the Codex I at least made a reference link to the get_ versions of these functions so that others will know they at least exist. next_posts_link() and previous_post_links() now provide mention and links to get_next_posts_link() and get_previous_posts_link().