Hi,
To display promotions from specific category, use this shortcode:
[promoslider category="my_category"]
I am not sure, but I think you have to put a category slug there, if not, then category ID. Take a look at more options at: FAQ.
To resize images to fit in the sidebar, you may use just simple CSS
#your_slider_id .promo_slider_background_image img {
/* replace pixels with your desired width and height */
width: 250px;
height: 100px;
}
That’s an easy way, but the harder (though more efficient) way is to modify promotion slider plugin and add new image sizes. I think you can also use filters in your functions.php, but not so sure if it works:
function add_my_image_sizes () {
// add_image_size('uniqueImageName', $width, $height, $crop_image_if_necessary);
add_image_size('banner', 250, 100, true);
}
add_filter('promoslider_image_size', 'add_my_image_sizes');
Maybe the owner of this plugin can help out with this one.