function when_images_loaded($img_container, callback){// do callback when images in $img_container (jQuery object) are loaded. Only works when ALL images in $img_container are newly inserted images and this function is called immediately after images are inserted into the target.
var _imgs = $img_container.find('img'),
img_length = _imgs.length,
img_load_cntr =0;
if(img_length){//if the $img_container contains new images.
_imgs.on('load',function(){//then we avoid the callback until images are loaded
img_load_cntr++;
if(img_load_cntr == img_length){
callback();
}
});
}
else{//otherwise just do the main callback action if there's no images in $img_container.