Don't Use the_title Filter in get_adjacent_post_rel_link()

[mordauk]

The get_adjacent_post_rel_link() function applies the the_title filter to the post title before setting it up in the <link> tags.

It's really common for the the_title filter to be used to modify the actual HTML markup of post titles (​see this example for adding product micro data), but this results in improperly formatting <link> tags. See ​this github issue for an example of the result.

get_adjacent_post_rel_link() should be using an equivalent to the_title_attribute() instead. Since there is not a get_the_title_attribute() function, I propose two options:

1. Introduce a get_the_title_attribute( $post_id ) function and then use this in get_adjacent_post_rel_link()

2. Simply remove apply_filters() and add in esc_attr( strip_tags( $title ) ) instead.

My vote would be to introduce a get_the_title_attribute() function.

[mordauk]

I'm opting for simply removing the "the_title" filter.

[markjaquith]

Hmm. I don't know. Injecting HTML like that seems wrong. Or that it should at least have an "in the loop" safety check. But that's besides the point. We should be using the_title_attribute() here (it has an echo flag).

[markjaquith]

Doh. But you can't pass in a post ID to the_title_attribute(). It is loop-only.

We can't lose the the_title filter here... that would be unexpected. We should, however, strip tags. Patch coming.

[markjaquith]

24232.2.diff​ Alternative approach: allow the_title_attribute() to take a post argument.

Note that this doesn't solve mordauk's issue. Instead, Pippin, I suggest that you put a safety check on your callback such that it bails if ! did_action( 'wp_head' ).

[nacin]

+1 commit on 24232.2.diff​.

[markjaquith]

In 24783:

Allow the_title_attribute() to receive a post argument, and use this in get_adjacent_post_rel_link() to make sure tags are stripped from the title output there.

Fixes #24232.

[mordauk]

Excellent, thanks Mark.

[DrewAPicture]

See [24783] for new $post arg in the_title_attribute()

[Jayjdk]

#14804 was marked as a duplicate.