product_images.py 文件源码

def get_thumbnail(instance, size, method='crop'):
    size_name = '%s__%s' % (method, size)
    if instance:
        if (size_name not in AVAILABLE_SIZES and not
                settings.VERSATILEIMAGEFIELD_SETTINGS['create_images_on_demand']):
            msg = ('Thumbnail size %s is not defined in settings '
                   'and it won\'t be generated automatically' % size_name)
            warnings.warn(msg)
        try:
            if method == 'crop':
                thumbnail = instance.crop[size]
            else:
                thumbnail = instance.thumbnail[size]
        except:
            logger.exception('Thumbnail fetch failed',
                             extra={'instance': instance, 'size': size})
        else:
            return thumbnail.url
    return static(choose_placeholder(size))