1: <?php
 2: 
 3: namespace Cron;
 4: 
 5: /**
 6:  * CRON field interface
 7:  */
 8: interface FieldInterface
 9: {
10:     /**
11:      * Check if the respective value of a DateTime field satisfies a CRON exp
12:      *
13:      * @param DateTime $date  DateTime object to check
14:      * @param string   $value CRON expression to test against
15:      *
16:      * @return bool Returns TRUE if satisfied, FALSE otherwise
17:      */
18:     public function isSatisfiedBy(\DateTime $date, $value);
19: 
20:     /**
21:      * When a CRON expression is not satisfied, this method is used to increment
22:      * or decrement a DateTime object by the unit of the cron field
23:      *
24:      * @param DateTime $date   DateTime object to change
25:      * @param bool     $invert (optional) Set to TRUE to decrement
26:      *
27:      * @return FieldInterface
28:      */
29:     public function increment(\DateTime $date, $invert = false);
30: 
31:     /**
32:      * Validates a CRON expression for a given field
33:      *
34:      * @param string $value CRON expression value to validate
35:      *
36:      * @return bool Returns TRUE if valid, FALSE otherwise
37:      */
38:     public function validate($value);
39: }
40: