Handling Ajax requests errors isn’t documented really well and there are many ways to accomplish this, some are simple and some are pretty darn complicated.
the easiest solution I found was rendering different partials depending on the status of the save or update methods, here is a snippet
def update
@bid = Bid.find(params[:id])
respond_to do |format|
if @bid.update_attributes(params[:bid])
flash[:notice] = 'Bid was successfully updated.'
format.js { render :partial => "update" }
else
format.js { render :partial => "update_fail"}
end
end
end
It may not be the most elegant solution but is sure simple and does what it says it does.