Post thumbnails ... either I'm doing something stupid or WordPress is broken

[Ryan]

Any ideas why I get the following HTML (ie: incorrect width):

<img width="470" height="304" src="http://domain.com/wp-content/uploads/test.jpg" class="attachment-post-thumbnail wp-post-image" alt="" title="test-470x304[1]" />

With the following theme code?

functions.php

 add_theme_support( 'post-thumbnails' );
add_theme_support( 'page-thumbnails' );
set_post_thumbnail_size( 470, 304, true ); // Normal post thumbnails
add_image_size( 'single-post-thumbnail', 150, 9999 ); 
  

single.php

 the_post_thumbnail( 'single-post-thumbnail' ); 
  

The thumbnail should be 150 pixels wide, not 470 pixels as it should be using the 'single-post-thumbnail' image size ... but it's not



I'm slowly going insane trying to figure out what I'm doing wrong. I've had this issue about 20x now and by some miracle I occasionally get it to work, but then other times (like now) I can't get it to work at all

[kucrut]

The add_image_size function will only work on newly uploaded images. If wordpress couldn't find the size you specified in the argument for the_post_thumbnail function, I think it will revert to the default you set, which is 470.

To regenerate the thumbnails you can use this plugin http://wordpress.org/extend/plugins/...te-thumbnails/

[Ryan]

No, that's not the problem. It happens on brand new thumbnails. I also tried that plugin but it didn't do anything useful :(

[kucrut]

Maybe you can try and add a new thumbnail size with hard-cropping enabled, say

 add_image_size( 'test-thumbnail',  160, 160, true ); 
  

...regenerate the thumbnails, and try it with the_post_thumbnail function on the frontend.

Personally I've never had any problem with this feature, so I'm a bit curious :)

[Ryan]

It's still 470 pixels wide :(

[Ryan]

Bingo, I figured out what the problem was!

The actual code I was using was:

 if ( the_post_thumbnail() )
    the_post_thumbnail( 'test-thumbnail' ); 
  

The check for whether there was a thumbnail or not was somehow messing with the actual call to the the_post_thumbnail.

I guess I need to check for the presence of a post thumbnail some other way.

[kucrut]

Ouch, it should be has_post_thumbnail() :)

[Ryan]

Oh heck! On looking back through the last few themes I've written which use post thumbnails they're totally riddled with that same check :( I'd been doing some crazy looking hacks to force these things to work as expected. I just kept thinking the thumbnail system was buggy, but no, my code was buggy and I'd been copy and pasting the same bug over and over again :(