Beginner struggling with update_attribute command

I am in the process of trying to use the update_attribute command, but struggling to get it working (at all) and hoped someone could point me in the right direction?

I have previously posted a question about this issue, it was very useful in terms of giving a feel for the mechanics of what is going on, but unfortunately it didn't actually get it working.

I have a database of items (Items), which among other things contains ':item_name', ':click_count' and ':external_url'.

Currently I have a view (Showselecteditems) in which there is a list of all the items, when a user clicks on an item name, they are directed to the appropriate external url. This works using the code:

<%= link_to selecteditem.item_name.to_s, selecteditem.external_url %>

I would now like to add the ability to count the number of times a particular item name has been clicked on (i.e. in total for all users, not individual users) and therefore the number of times each external url has been visited in order to work out which is most popular.

Reading around, I believe i need to modify the code above to something of the form:

<%= link_to selecteditem.item_name.to_s, selecteditem.external_url, {:controller => params[:controller], :action => clickcountplusone, :identifier => selecteditem.item_name} %>

And need to define this function somewhere - it seems to only be found if located in 'application_helper'?

def clickcountplusone
    clickeditem = Items.find(params[:ident开发者_C百科ifier])
    clickeditem.update_attribute(:click_count, clickeditem.click_count + 1)
    rescue ActiveRecord::RecordNotFound # to avoid error if no identifier value
end

Needless to say, I cannot get this to work... My question is therefore, how can I set things up correctly so that when the link is clicked on the count is incremented? The other common problem people seem to report is that the number will be incremented each time the page is refreshed, which I would like to avod if possible.

Previously people have suggested adding to the 'show' section of the 'Items' controller, however, i don't know how this would work as the links are being clicked on the Showselecteditems view page, not the database itself where you get the show, edit, destroy commands. Any advice greatly appreciated.

This

<%= link_to selecteditem.item_name.to_s, selecteditem.external_url, {:controller => params[:controller], :action => clickcountplusone, :identifier => selecteditem.item_name} %>

will not point user to the some_controller#clickcountplusone, because you already specified an external link.

The easiest way to do this job is to modify your link_to like:

<%= link_to selecteditem.item_name.to_s, {:controller => params[:controller], :action => clickcountplusone, :identifier => selecteditem.item_name} %>

And then to modify your actions source:

def clickcountplusone
  clickeditem = Items.find(params[:identifier])
  redirect_to clickeditem.external_url if clickeditem.update_attribute(:click_count, clickeditem.click_count + 1)
  rescue ActiveRecord::RecordNotFound # to avoid error if no identifier value
end