Next/Previous links doesn't work in the same category

Question

I created a category and call it "Blog". Then I created some posts and assign "Blog" as category for the posts. So I'm trying to go to previous/next into the same category and doesn't work. Here is my code:

<nav id="nav-single">
    <span class="nav-previous"><?php previous_post_link('%link', __('<span class="meta-nav">&larr;</span> Previous'), TRUE); ?></span>
    <span class="nav-next"><?php next_post_link('%link', __('Next <span class="meta-nav">&rarr;</span>'), TRUE); ?></span>
</nav><!-- #nav-single -->

None of the links is being displayed even if I have more than one post created. If I remove the TRUE value then it goes to other categories. What am I doing wrong?

Answer 1

This is the default in WordPress Twenty Eleven Theme

<nav id="nav-single">
        <h3 class="assistive-text"><?php _e( 'Post navigation', 'twentyeleven' ); ?></h3>
        <span class="nav-previous"><?php previous_post_link( '%link', __( '<span class="meta-nav">&larr;</span> Previous', 'twentyeleven' ) ); ?></span>
        <span class="nav-next"><?php next_post_link( '%link', __( 'Next <span class="meta-nav">&rarr;</span>', 'twentyeleven' ) ); ?></span>
</nav><!-- #nav-single -->

I copy pasted your code to replace the above default code.

<nav id="nav-single">
    <span class="nav-previous"><?php previous_post_link('%link', __('<span class="meta-nav">&larr;</span> Previous'), TRUE); ?></span>
    <span class="nav-next"><?php next_post_link('%link', __('Next <span class="meta-nav">&rarr;</span>'), TRUE); ?></span>
</nav><!-- #nav-single -->

Your code is working perfectly on my system. Your code doesn't have any problem. You can refer to Codex for changing your code further.

http://codex.wordpress.org/Function_Reference/previous_post_link

Answer 2

This worked for me:

<div id="nav-single">           
<div class="nav-previous"><?php previous_post_link('&#8249; %link', '%title', 'Next post in category', TRUE); ?> </div>
<div class="nav-next"><?php next_post_link('%link &#8250;', '%title', 'Next post in category', TRUE); ?> </div>         
</div><!-- end of #nav-single -->'

Answer 3

I had the same problem, and I found, after reading well the codex, that my post type had a custom taxonomy, not named "category" (default to WP), but "categories", so to be functional here the code I had to write:

<?php previous_post_link('%link', '<i title="Previous Project" class="prev"></i>', true, array(), 'categories') ?>
<?php next_post_link('%link', '<i title="Next Project" class="prev"></i>', true, array(), 'categories') ?>