In PHP since the interface benefits can used by passing as parameter mentioning the Interface name something like
public function foo (Abc $abc){}
where Abc is an interface.But how do I pass an array of these interfaces?
Please note this not class but interface and only way to get advantage of interface is passing as function with type hinting
In PHP 5.6+ you could do something like this:
function foo(Abc ...$args) {
}
foo(...$arr);
foo() takes a variable amount of arguments of type Abc, and by calling foo(...$arr) you unpack $arr into a list of arguments. If $arr contains anything other than instances of Abc an error will be thrown.
This is a little 'hacky', but it's the only way to get type hinting for an array in PHP, without putting down some extra code.
Unfortunately, you cannot check for two different interfaces at the same time using type hinting in PHP, but you can write a function for this which will check if the object belongs to multiple interfaces, eg -
function belongs_to_Interfaces($obj,array $interfaces)
{
foreach($interfaces as $interface)
{
if(!is_a($obj,$interface))
{
return false;
}
}
return true;
}
You can then use it like this,
public function foo ($abc){
if(!belongs_to_Interfaces($abc, ['interface1', 'interface2'])){
//throw an error or return false
}
}
if you use PHP 5.6+ you can use variadic with decorator pattern:
<?php
interface Rule {
public function isSatisfied();
}
final class ChainRule implements Rule {
private $rules;
public function __construct(Rule ...$rules) {
$this->rules = $rules;
}
public function isSatisfied() {
foreach($this->rules as $rule)
$rule->isSatisfied();
}
}
Vector<Abc>to type hint a Vector (zero indexed list). Sadly PHP itself doesn't offer this afaik, at least not yet. You could hack your way around it though: ensure you are working with "Array of Foo"