coldfusion session refresh

Question

Is there a way to refresh coldfusion session on the page without reloading the page? Let's say I had 3 items in my shopping cart. Now I want to remove one of the items by clicking "remove" link next to a product. I created delete_item.cfm that removes a particular item from cart using jquery ajax. Now I want my shopping cart to display only 2 items without reloading the page. Here is my code.

<CFIF ISDEFINED("ProductID")>
    <!--- Find where in the basket it is --->
    <CFSET ItemPosition = ListFind(session.StoreItems,ProductID)>       
    <CFSET session.StoreItems = ListDeleteAt(session.StoreItems, ItemPosition, ",")>
    <CFSET session.StoreItemsQty = ListDeleteAt(session.StoreItemsQty, ItemPosition, ",")>

Ken Redler Ken Redler · Accepted Answer · 2011-03-11T03:36:12

This has little to do with ColdFusion specifically, and more to do with a very common Ajax design pattern. You've got most of it right; here's the general idea:

User clicks [delete].

A JavaScript handler function sends the ID of the item to be deleted to your delete_item.cfm handler on the server. Example:

$('a.deletelink').click( function(e){
  e.preventDefault();
  $.ajax({ 
    url : '/handlers/delete_item.cfm',
    data : $(this).data('id'),
    type : 'post',
    success : /* see below */
  });
});

On the server, another function retrieves an updated view of the region of the page affected by the change -- now without the deleted item. delete_item.cfm calls this function and returns the updated view information to the Ajax requester. This could take the form of:
- The raw data, perhaps in the form of a JSON string, or...
- A fully rendered HTML version of the region to be re-drawn.
In the success handler of the Ajax call, the updated view information is received. You then:
- Loop over the JSON data and build the appropriate HTML in JavaScript, then drop it into your container area (perhaps using a templating engine), or...
- Drop in the fully rendered HTML as supplied from delete_item.cfm, replacing the older version that originally contained the item you're deleting.
Example:
```
/* success handler from above */
function(data){ // data is what's returned from delete_item.cfm
                // Assuming it's fully rendered HTML post-deletion:
  $('#container_of_your_list')
    .html( data ) // drop in new data
    .effect('highlight',{},2000); // visual feedback to user
}
```

coldfusion session refresh

2 Answers