Why am I getting this Strict Standards message?

Question

I have created a Zend Framework model by extending Zend_Db_Table_Absract as follows (simplified example):

class Foos extends Zend_Db_Table_Abstract
{
    protected $_schema = 'Foo';
    protected $_name = 'Foos';
    protected $_primary = 'id';
    protected $_sequence = true;

    public function insert($data) {
        $db = $this->getAdapter();
        $record = array('field1' => $data['field1'],
                        'field2' => $data['field2'],
                        ...
                );
        return parent::insert($record);
    }
}

The above correctly inserts a record. The problem is, I keep getting the following notice:

Strict Standards: Declaration of Foos::insert() should be compatible with that of Zend_Db_Table_Abstract::insert() in /x/x/x/Foo.php on line XX

As far as I can tell from having read the documentation and API several times, the way I am doing it is correct. I am aware that I can turn off E_STRICT but I would much rather know why I am getting the above notice. Any ideas? (PHP 5.3, Zend Framework 1.10)

Answer 1

Mchl is mostly correct but the error you're getting is from the parameter not matching exactly i.e.:

public function insert($data) {

should be:

public function insert(array $data) {

note the array type specifier before $data, the mixed you're seeing is the return type, the argument type is array.

Answer 2

it has to be public function insert(array $data) (notice the array typehint before $data)

Answer 3

The error itself is because you have E_STRICT set in error_reporting or the error_reporting ini directive...

Basically, what it's saying is that it's not good practice to change the "signature" of a function through inheritance. An example:

class ParentClass {
    public function doFoo() {}
}

class ChildClass extends ParentClass {
    public function doFoo($bar) {}
}

That would generate this error since the parent and child signatures don't match. Now, the signature is what it looks like to the parser, so :

public function doFoo($bar) {}
public function doFoo($baz) {}

Are both matching signatures. The variable names don't need to be the same, but the number of variables, their order, their type hints, and their default values must be the same.

public function doFoo(array $bar, ParentClass $somethign, $biz = 'no') {}
public function doFoo(array $baz, ParentClass $parent, $buz = 'no') {}

They match as well, but these do not:

public function doFoo(array $baz, ParentClass $parent, $buz = 'no') {}
public function doFoo(array $baz, ChildClass $parent, $buz = 'no') {}

It's not necessarily "bad" to do (frameworks and developers do it all the time). Right now the language supports it fine. The reason for the E_STRICT error is that in the future the language may not support it. So it "warns you" that it may be a bad idea to use your design like that...

Answer 4

Because you Foos::insert() method has different signature (list of arguments, access modifier) from Zend_Db_Table_Abstract::insert(). According to strict rules, methods in child class that override methods in parent class, need to have same signature.

[edit]

At least that's what it usually means, because looking at Zend_Db_Table_Abstract::insert() documentation, I can't see nothing different...

[edit]

Check in Zend_Db_Table_Abstract::insert() if there is a type hint for $data argument. It might be public function insert(array $data) {...