/**
* Default image
*
* Builds an default <img> for use in themes or plugins before any other images are added.
* Resizes & crops the image using the built-in (retireved via `get_intermediate_image_sizes();`)
* or custom image (added via `add_image_size();`) sizes.
*
* Retrieves calculated resize dimension @uses image_resize_dimensions();
* Builds the width and height string @uses image_hwstring();
*
* @param $args (array)
* string $url URl to the given default image.
* string $size Optional. Default is 'medium'.
* string (optional) $alt Image Description for the alt attribute.
* string (optional) $title Image Description for the title attribute.
* string (optional) $align Part of the class name for aligning the image.
* string (optional) $echo Wheter to return or echo the $image
* @return string HTML IMG element for given image attachment
*/
function oxo_default_img( $attr )
{
// Sizes registered via add_image_size();
global $_wp_additional_image_sizes;

$defaults = array(
'size' => 'medium'
,'classes' => false
,'alt' => false
,'title' => false
,'align' => 'none'
,'echo' => true
);

$attr = wp_parse_args( $attr, $defaults );

if ( 'thumb' === $attr['size'] )
$attr['size'] = 'thumbnail';

// Size in built in sizes - call size setting from DB
# behavoir in here dependent on @link http://core.trac.wordpress.org/ticket/18947
if ( ! in_array( $attr['size'], array_keys( $_wp_additional_image_sizes ) ) )
{
$sizes = get_intermediate_image_sizes();
// Get option - gladly autoloaded/can use wp_cache_get();
$size_data['width'] = intval( get_option( "{$attr['size']}_size_w") );
$size_data['height']= intval( get_option( "{$attr['size']}_size_h") );
// Not sure how this will behave if cropped is false (autoloaded option not added)
$size_data['crop'] = get_option( "{$attr['size']}_crop" ) ? get_option( "{$attr['size']}_crop" ) : false;
}
// Size array from global registered additional/custom sizes array
else
{
$size_data = $_wp_additional_image_sizes[ $attr['size'] ];
}

// Retrieve image width & height
$img_info = @getimagesize( $attr['url'] );

// Calculate final dimensions - if "crop" was set to true during add_image_size(), the img will get ... cropped
$end_sizes = image_resize_dimensions( $img_info[0], $img_info[1], $size_data['width'], $size_data['height'], $size_data['crop'] );

// defaults to px units - can't get changed, as applying units is not possible
$hwstring = ' '.trim( image_hwstring( $end_sizes[4], $end_sizes[5] ) );

// Attributes:
// Not made required as users tend to do funky things (...and lock screen readers out)
$attr['alt'] = $attr['alt'] ? ' alt="'.esc_attr( $attr['alt'] )."'" : '';

if ( ! $attr['title'] )
$attr['title'] = sprintf( __('default image of type: %1$s'), explode( "/", $img_info['mime'] ) );
$attr['title'] = $attr['title'] ? ' title="'.esc_attr( $attr['title'] )."'" : '';

$attr['classes'] = "wp-img-default ".esc_attr( $attr['classes'] ? $attr['classes'] : '' );
$attr['align'] = $attr['align'] ? "align".esc_attr( $attr['align'] ) : '';
$attr['size'] = "size-".esc_attr( $attr['size'] );

// Allow filtering of the default attributes
$attributes = apply_filters( 'wp_default_img_attr', $attr );

// Build class attribute, considering that maybe some attribute was unset via the filter
$classes = ' class="';
$classes .= 'wp-img-default'.esc_attr( $attr['classes'] ? ' '.$attr['classes'] : '' );
$classes .= $attr['align'] ? ' '.esc_attr( $attr['align'] ) : '';
$classes .= $attr['size'] ? ' '.esc_attr( $attr['size'] ).'" ' : '" ';

$url = trim( $attr['url'] );
$image = "<img src='{$url}'{$hwstring}{$classes}".$attr['alt'].$attr['title']." />";
$image = apply_filters( 'wp_default_img', $image );

if ( ! $attr['echo'] )
return $image;

return print $image;
}