How do you add_filter to only one instance of the_title() - wordpress

Question

I created a filter that modifies the_title() of a post, but the problem I'm having is that it's modifying every instance of the_title(). I got most of the problem sorted out with the in_the_loop() function, however any theme that has "next post" "previous post" navigation links within the loop are still having the filter applied (understandably so). How can I apply the filter to only the the_title() of the current post?
function xyz_the_title( $the_title ) {
if( !in_the_loop() )
return $the_title;
$location = get_post_meta( get_the_ID(), 'location', true );
$the_title .= ' - ' . $location;
return $the_title;
}
add_filter( 'the_title', 'xyz_the_title' );

Answer 1

do it with jQuery
Something like this should do the trick:
$(document).ready(function() {
$('#entry-header').text(function(i, oldText) {
return oldText === 'Popular Science' ? 'New word' : oldText;
});
});
This only replaces the content when it is Popular Science. See text in the jQuery API.

Answer 2

Rather than filtering the_title you could edit your template file instead and append the location to your returned the_title().
echo "<h1>" . get_the_title() . " - " . $location . "</h1>";

Answer 3

Ran into a similar situation and was hoping this thread could save me...
Anyways this is what I managed to do thus far in
add_filter( 'the_title', function( $title, $id ){
/**
* don't run in the backend
*/
if( is_admin() ) {
return $title;
}
/**
* invalid values received
*/
if( empty( $title ) || $id < 1 ){
return $title;
}
global $post;
if ( ! $post instanceof WP_Post ){
return $title;
}
/**
* PREVENTATIVE MEASURE...
* only apply the filter to the current page's title,
* and not to the other title's on the current page
*/
global $wp_query;
if( $id !== $wp_query->queried_object_id ){
return $title;
}
/**
* Don't run this filter if wp_head calls it
*/
if( doing_action( 'wp_head' ) ){
return $title;
}
return 'MODIFIED - '.$title;
});
Here are the shortfalls:
If you have the same post being displayed on the current page, somewhere else, it's gonna modify THAT post title as well
Currently thinking about having a look at the call stack to detect if the call is coming from the theme...
but I would suggest you find another solution bud...

Answer 4

Ah, didn't know it was for a plugin. In which case, I think you should be ok to use if_filter then. This checks whether the filter has been run x times on the page in question. So, we check if it has run once on the page and if so it won't run again. Also, I have assumed you only want this to run on single post pages. This is untested.
function xyz_the_title( $the_title ) {
if( is_single() AND did_filter('the_title') === 1 ) {
if( !in_the_loop() )
return $the_title;
$location = get_post_meta( get_the_ID(), 'location', true );
$the_title .= ' - ' . $location;
return $the_title;
}
}
add_filter( 'the_title', 'xyz_the_title' );