| 1 | <?php |
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| 14 | class Collection implements Countable, IteratorAggregate |
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| 15 | { |
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| 16 | |||
| 17 | /** |
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| 18 | * @var array |
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| 19 | */ |
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| 20 | protected $data = array(); |
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| 21 | |||
| 22 | /** |
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| 23 | * Add to collection |
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| 24 | * |
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| 25 | * @param Model $model |
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| 26 | */ |
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| 27 | public function add(Model $model) |
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| 31 | |||
| 32 | /** |
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| 33 | * Collection count |
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| 34 | * |
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| 35 | * @return int|void |
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| 36 | */ |
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| 37 | public function count() |
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| 41 | |||
| 42 | /** |
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| 43 | * Get current |
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| 44 | * |
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| 45 | * @return Model |
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| 46 | */ |
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| 47 | public function current() |
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| 51 | |||
| 52 | /** |
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| 53 | * Get iterator |
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| 54 | * |
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| 55 | * @return ArrayIterator|Traversable |
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| 56 | */ |
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| 57 | public function getIterator() |
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| 61 | } |
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| 62 |
Let’s take a look at an example:
In the above example, the authenticate() method works fine as long as you just pass instances of MyUser. However, if you now also want to pass a different implementation of User which does not have a getDisplayName() method, the code will break.
Available Fixes
Change the type-hint for the parameter:
Add an additional type-check:
Add the method to the interface: