1: <?php
 2: 
 3: class TransactionOperation {
 4: 
 5:     private $operations = array();
 6: 
 7:     public function execute(UndoableOperation $operation) {
 8:         if (($result = $operation->run())) {
 9:             $this->operations[] = $operation;
10:             return $result;
11:         } else {
12:             $operation->undo();
13:             $this->rollback();
14:             throw new Exception("Error on executing \"$operation\"");
15:         }
16:     }
17: 
18:     /**
19:      * @return void
20:      */
21:     public function rollback() {
22:         while (!empty($this->operations)) {
23:             $operation = array_pop($this->operations);
24:             try {
25:                 $operation->undo();
26:             } catch (Exception $ex) {
27:                 //Ignores fail
28:             }
29:         }
30:     }
31: 
32:     /**
33:      * @return void
34:      */
35:     public function commit() {
36:         foreach ($this->operations as $operation) {
37:             if ($operation instanceof CommitableOperation) {
38:                 try {
39:                     $operation->commit();
40:                 } catch (Exception $ex) {
41:                     //Ignores fail
42:                 }
43:             }
44:         }
45:     }
46: 
47:     public function __toString() {
48:         $b = '';
49:         foreach ($this->operations as $operation) {
50:             $b .= "$operation\n";
51:         }
52:         return $b;
53:     }
54: 
55: }