I have a class like this:
class someClass {
public static function getBy($method,$value) {
// returns collection of objects of this class based on search criteria
$return_array = array();
$sql = // get some data "WHERE `$method` = '$value'
$result = mysql_query($sql);
while($row = mysql_fetch_assoc($result)) {
$new_obj = new $this($a,$b);
$return_array[] = $new_obj;
}
return $return_array;
}
}
My question is: can I use $this in the way I have above?
Instead of:
$new_obj = new $this($a,$b);
I could write:
$new_obj = new someClass($a,$b);
But then when I extend the class, I will have to override the method. If the first option works, I won't have to.
UPDATE on solutions:
Both of these work in the base class:
1.)
$new_obj = new static($a,$b);
2.)
$this_class = get_class();
$new_obj = new $this_class($a,$b);
I have not tried them in a child class yet, but I think #2 will fail there.
Also, this does not work:
$new_obj = new get_class()($a,$b);
It results in a parse error: Unexpected '(' It must be done in two steps, as in 2.) above, or better yet as in 1.).
Easy, use the static
keyword
public static function buildMeANewOne($a, $b) {
return new static($a, $b);
}
See http://php.net/manual/en/language.oop5.late-static-bindings.php .
You may use ReflectionClass::newInstance
class A
{
private $_a;
private $_b;
public function __construct($a = null, $b = null)
{
$this->_a = $a;
$this->_b = $b;
echo 'Constructed A instance with args: ' . $a . ', ' . $b . "\n";
}
public function construct_from_this()
{
$ref = new ReflectionClass($this);
return $ref->newInstance('a_value', 'b_value');
}
}
$foo = new A();
$result = $foo->construct_from_this();
Try using get_class(), this works even when the class is inherited
<?
class Test {
public function getName() {
return get_class() . "\n";
}
public function initiateClass() {
$class_name = get_class();
return new $class_name();
}
}
class Test2 extends Test {}
$test = new Test();
echo "Test 1 - " . $test->getName();
$test2 = new Test2();
echo "Test 2 - " . $test2->getName();
$test_initiated = $test2->initiateClass();
echo "Test Initiated - " . $test_initiated->getName();
When running, you'll get the following output.
Test 1 - Test
Test 2 - Test
Test Initiated - Test
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