Different size thumbnails on home and single pages

Question

small size thumbs are shown on the homepage which is fine, but I'd like to show large thumbs on single-page. This is a function in my functions.php:

function fix_my_gallery($output, $attr) {
    global $post;

    static $instance = 0;
    $instance++;


    /**
     *  will remove this since we don't want an endless loop going on here
    **/
    // Allow plugins/themes to override the default gallery template.
    // $output = apply_filters('post_gallery', '', $attr);

    // We're trusting author input, so let's at least make sure it looks like a valid orderby statement
    if ( isset( $attr['orderby'] ) ) {
        $attr['orderby'] = sanitize_sql_orderby( $attr['orderby'] );
        if ( !$attr['orderby'] )
            unset( $attr['orderby'] );
    }

    extract(shortcode_atts(array(
        'order'      => 'ASC',
        'orderby'    => 'menu_order ID',
        'id'         => $post->ID,
        'itemtag'    => 'li ',
        'icontag'    => 'a',
        'captiontag' => 'span',
        'columns'    => 1,
        'size'       => 'thumbnail',
        'include'    => '',
        'exclude'    => ''
    ), $attr));

    $id = intval($id);
    if ( 'RAND' == $order )
        $orderby = 'none';

    if ( !empty($include) ) {
        $include = preg_replace( '/[^0-9,]+/', '', $include );
        $_attachments = get_posts( array('include' => $include, 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => $order, 'orderby' => $orderby) );

        $attachments = array();
        foreach ( $_attachments as $key => $val ) {
            $attachments[$val->ID] = $_attachments[$key];
        }
    } elseif ( !empty($exclude) ) {
        $exclude = preg_replace( '/[^0-9,]+/', '', $exclude );
        $attachments = get_children( array('post_parent' => $id, 'exclude' => $exclude, 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => $order, 'orderby' => $orderby) );
    } else {
        $attachments = get_children( array('post_parent' => $id, 'post_status' => 'inherit', 'post_type' => 'attachment', 'post_mime_type' => 'image', 'order' => $order, 'orderby' => $orderby) );
    }

    if ( empty($attachments) )
        return '';

    if ( is_feed() ) {
        $output = "\n";
        foreach ( $attachments as $att_id => $attachment )
            $output .= wp_get_attachment_link($att_id, $size, true) . "\n";
        return $output;
    }

    $itemtag = tag_escape($itemtag);
    $captiontag = tag_escape($captiontag);
    $columns = intval($columns);
    $itemwidth = $columns > 0 ? floor(100/$columns) : 100;
    $float = is_rtl() ? 'right' : 'left';

    $selector = "gallery-{$instance}";

    $gallery_style = $gallery_div = '';
    if ( apply_filters( 'use_default_gallery_style', true ) )
    $size_class = sanitize_html_class( $size );
    $gallery_div = "<ul id='$selector' class='gallery galleryid-{$id} gallery-columns-{$columns} gallery-size-{$size_class}'>";
    $output = apply_filters( 'gallery_style', $gallery_style . "\n\t\t" . $gallery_div );

    $i = 0;
    foreach ( $attachments as $id => $attachment ) {
        $link = isset($attr['link']) && 'file' == $attr['link'] ? wp_get_attachment_link($id, $size, false, false) : wp_get_attachment_link($id, $size, true, false);

        $output .= "<{$itemtag} class='gallery-item'>";
        $output .= "$link";
        $output .= "</{$itemtag}>";
        if ( $columns > 0 && ++$i % $columns == 0 )
            $output .= '';
    }
    $output .= "</ul>\n";
    return $output;
}
add_filter("post_gallery", "fix_my_gallery",10,2);

I can't quite figure how to add a condition if its a single page, show different size.

Thanks!

Answer 1

You can change variable $size value depending on what page is viewed.

$size = is_single() ? 'large' : 'thumbnail';

Code above will set $size to large, if is_single is true, else it would be thumbnail (or small as you said). Place it somewhere below shortcode attribute extract.