Add attribute to wp_get_attachment_image

Question

I'm trying to add an attribute to the result of wp_get_attachment_image.

I want to use jquery lazyload to handle loading of my post thumbnails and to do that I need to add a data-original= attribute to the <img> tag wp_get_attachment_image is creating.

I've tried:

$imgsrc = wp_get_attachment_image_src( get_post_thumbnail_id($post->ID), "full" );
$imgsrc = $imgsrc[0];
$placeholderimg = wp_get_attachment_image( 2897, "full", array('data-original'=>$imgsrc) );

But it doesn't add the data attribute as I expected.

<img class="attachment-full" width="759" height="278" alt="..." src="..."></img>

Looking at the wp_get_attachment_image function it would seem that this ought to work though:

function wp_get_attachment_image($attachment_id, $size = 'thumbnail', $icon = false, $attr = '') {
     
 
    $html = '';
 
    $image = wp_get_attachment_image_src($attachment_id, $size, $icon);
 
    if ( $image ) {
 
        list($src, $width, $height) = $image;
 
        $hwstring = image_hwstring($width, $height);
 
        if ( is_array($size) )
 
            $size = join('x', $size);
 
        $attachment =& get_post($attachment_id);
 
        $default_attr = array(
 
            'src'   => $src,
 
            'class' => "attachment-$size",
 
            'alt'   => trim(strip_tags( get_post_meta($attachment_id, '_wp_attachment_image_alt', true) )), // Use Alt field first
 
            'title' => trim(strip_tags( $attachment->post_title )),
 
        );
 
        if ( empty($default_attr['alt']) )
 
            $default_attr['alt'] = trim(strip_tags( $attachment->post_excerpt )); // If not, Use the Caption
 
        if ( empty($default_attr['alt']) )
 
            $default_attr['alt'] = trim(strip_tags( $attachment->post_title )); // Finally, use the title
 
 
 
        $attr = wp_parse_args($attr, $default_attr);
 
        $attr = apply_filters( 'wp_get_attachment_image_attributes', $attr, $attachment );
 
        $attr = array_map( 'esc_attr', $attr );
 
        $html = rtrim("<img $hwstring");
 
        foreach ( $attr as $name => $value ) {
 
            $html .= " $name=" . '"' . $value . '"';
 
        }
 
        $html .= ' />';
 
    }
 
 
 
    return $html;
 
}

Where am I going wrong?

[update] Sometimes it just takes a fresh pair of eyes to spot the idiocy... Thanks to hobo I realised I simply missed out a parameter in my function call :D :P

Answer 1

I haven't tested, but I think the problem is your array should be the fourth argument to wp_get_attachment_image, not the third.

So

$placeholderimg = wp_get_attachment_image( 2897, "full", array('data-original'=>$imgsrc) );

should be

$placeholderimg = wp_get_attachment_image( 2897, "full", false, array('data-original'=>$imgsrc) );

assuming you're happy with the default value (false) of the $icon argument.