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1. Kalon
   Member
   Posted 4 years ago #

   Hello,

   At the end of a post I use the following for the next/previous post navigation:

   <?php previous_post_link('<small>Previous post:</small>&laquo; %link') ?>
   
   <?php next_post_link('<small>Next post:</small>%link &raquo;') ?>

   This way, I don't get the "Next post:" or "Previous post:" text if there isn't a next or previous post.

   I would like to achieve the same thing with the next/previous image navigation in the gallery.

   At the moment I am using:

   <small>Previous image:</small><?php previous_image_link() ?>
   <small>Next image:</small><?php next_image_link() ?>

   This will still display the "next image" text regardless if there is a next image or not.

   What can I do with the next_image_link() and previous_image_link() so as to make it only display the next or previous image text if there actually is a next or previous image?

   Cheers,
   Kalon.

2. Michael Fields
   Theme Wrangler
   Posted 4 years ago #

   Kalon,

   Hi. Unfortunately, these functions are not pluggable and don't return anything on failure. This will most likely be addressed in a future release. Until then, the best advice that I can offer you is to write your own functions (or use mine below) that do exactly as you want.

   Add To: functions.php

   function mf_previous_image_link( $text ) {
       $i = mf_adjacent_image_link( true );
   	if ( $i )
   		print $text . $i;
   }
   
   function mf_next_image_link( $text ) {
       $i = mf_adjacent_image_link( false );
   	if ( $i )
   		print $text . $i;
   }
   
   function mf_adjacent_image_link($prev = true) {
       global $post;
       $post = get_post($post);
       $attachments = array_values(get_children("post_parent=$post->post_parent&post_type=attachment&post_mime_type=image&orderby=\"menu_order ASC, ID ASC\""));
   
       foreach ( $attachments as $k => $attachment )
           if ( $attachment->ID == $post->ID )
               break;
   
       $k = $prev ? $k - 1 : $k + 1;
   
       if ( isset($attachments[$k]) )
           return wp_get_attachment_link($attachments[$k]->ID, 'thumbnail', true);
   	else
   		return false;
   }

   Add To: image.php

   <small><?php mf_previous_image_link( 'Previous Image' ) ?></small>
   <small><?php mf_next_image_link( 'Next Image' ) ?></small>

   Please let me know how this works!

3. Kalon
   Member
   Posted 4 years ago #

   Thank you for your time mfields, your code works perfectly.

   My blog is currently on my localhost, while I develop it and find a host that isn't complete pants, but you can see the navigation part in the below screenshot:

   http://img177.imageshack.us/img177/4522/screen2xc1.gif

   Again, thanks for your help,
   Kalon.

4. Michael Fields
   Theme Wrangler
   Posted 4 years ago #

   Kalon,
   Glad it worked for you!

5. Firkraag85
   Member
   Posted 4 years ago #

   Hi,

   What about a custom image? For example arrows for previous and next.

   Thanks in advance!

6. leinert
   Member
   Posted 3 years ago #

   Hi,
   I've been quit lucky after I read this thread, because such kind of function I am looking for. But after copy and past of that code sniplets I get this error message:

   Warning: array_values() [function.array-values]: The argument should be an array in /var/kunden/webs/leinert/wordpress/wp-includes/functions.php on line 1767

   Warning: Invalid argument supplied for foreach() in /var/kunden/webs/leinert/wordpress/wp-includes/functions.php on line 1769

   What has been changed in get_children?

   Please help! I do not want to wait for 2.6!

7. Anonymous
   Unregistered
   Posted 3 years ago #

   get_children needs its arguments as an array now. This should be good for 2.6:
   

   function mf_previous_image_link( $text ) {
       $i = mf_adjacent_image_link( true );
   	if ( $i )
   		print $text . $i;
   }
   
   function mf_next_image_link( $text ) {
       $i = mf_adjacent_image_link( false );
   	if ( $i )
   		print $text . $i;
   }
   
   function mf_adjacent_image_link($prev = true) {
       global $post;
       $post = get_post($post);
       $attachments = array_values(get_children(
   Array('post_parent' => $post->post_parent,
         'post_type' => 'attachment',
         'post_mime_type' => 'image',
         'orderby' => 'menu_order ASC, ID ASC')));
   
       foreach ( $attachments as $k => $attachment )
           if ( $attachment->ID == $post->ID )
               break;
   
       $k = $prev ? $k - 1 : $k + 1;
   
       if ( isset($attachments[$k]) )
           return wp_get_attachment_link($attachments[$k]->ID, 'thumbnail', true);
   	else
   		return false;

8. flammable
   Member
   Posted 3 years ago #

   Or, if you'd prefer, the author has changed it to a plugin:

   http://mfields.org/wordpress-plugins/text-based-image-links/

   :)

9. pstagg
   Member
   Posted 3 years ago #

   Some may be interested in this variant:

   For image links I wanted something functional equivalent to:
   previous_post_link('<li>%link</li>');

   So thanks to this thread I came up with this:

   In functions.php:

   function ps_previous_image_link( $f ) {
       $i = ps_adjacent_image_link( true );
   	if ( $i ) {
   		echo str_replace("%link", $i, $f);
   	}
   }
   
   function ps_next_image_link( $f ) {
       $i = ps_adjacent_image_link( false );
   	if ( $i ) {
   		echo str_replace("%link", $i, $f);
   	}
   }
   
   function ps_adjacent_image_link($prev = true) {
       global $post;
       $post = get_post($post);
       $attachments = array_values(get_children(Array('post_parent' => $post->post_parent,
   	      'post_type' => 'attachment',
   	      'post_mime_type' => 'image',
   	      'orderby' => 'menu_order ASC, ID ASC')));
   
       foreach ( $attachments as $k => $attachment ) {
           if ( $attachment->ID == $post->ID ) {
               break;
   		}
   	}
   
       $k = $prev ? $k - 1 : $k + 1;
   
       if ( isset($attachments[$k]) ) {
           return wp_get_attachment_link($attachments[$k]->ID, 'thumbnail', true);
   	}
   	else {
   		return false;
   	}
   }

   In image.php:

   <ol>
   <?php ps_previous_image_link( '<li>%link</li>' ) ?>
   <?php ps_next_image_link( '<li>%link</li>' ) ?>
   </ol>

   Thanks guys.

10. Tarmu
    Member
    Posted 3 years ago #

    @pstagg

    I only think that you have confused previous & next :D

11. Tarmu
    Member
    Posted 3 years ago #

    @pstagg, can you help me, I would like to add #photo to the URL the generated thumbnail links to.

12. Tarmu
    Member
    Posted 3 years ago #

    Or anybody else of course..

    I'm using the code above from pstagg. It's generating thumbnails to link to the next and prev images.

    I just want to add #photo to the generated url. Should be simple, but I can't find it.

13. Tarmu
    Member
    Posted 3 years ago #

    no one?

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