Ubercart

Same request here!
Fivestar is fine but allow everybody to vote...

May be an idea:
Read only fivestar on products page and products list
Create a vote-allowed role and a buyer role

I someone make an order, then when the order status is terminated, his role change from buyer to vote-allowed
Then he can go to his order page, where he can vote with a write enable fivestar.

Found some snippets on the internet I put together on Drupal 6. I'm using Ubercart and Ubercart marketplace though should work with just Ubercart alone in theory. (Has not been thoroughly tested yet but seems to work)

Change the fivestar.module file to be this (the main change is that user_purchased call) and add the user_purchased function below:

function fivestar_fivestar_access($type, $id, $uid) {
if ($type == 'node' && $node = node_load($id)) {
if (variable_get('fivestar_'. $node->type, 0)) {
if (user_purchased($id))
{
return TRUE;
}
}
}
}

/**
* Implementation of user_purchased().
*
* This function checks if the user has purchased this product already
*
*
* @return true, false
* true if user purchased, false otherwise
*
*
*/
function user_purchased($nid){
global $user;
$sql = "SELECT uop.nid FROM {uc_order_products} uop
LEFT JOIN {uc_orders} uo ON uo.order_id = uop.order_id
WHERE uo.uid = %d AND uop.nid = %d AND uo.order_status in ('completed', 'payment_received')";
$rs = db_query($sql, array($user->uid, $nid));
$row = db_fetch_object($rs);
return $row->nid;
}

Would love to find this as well- because we are getting a lot of "spammers" leaving spam posts on our 5 star rating product comments. ARG.

Take a look at the two functions posted above. if you modify fivestars fivestar.module file with those it should work. Replace the access function with the new one. Add the second function there. Give it a try...