dynamic class names in php

Question

I have a base class called field and classes that extend this class such as text, select, radio, checkbox, <

Answer 1

This should be enough:

$field_type = 'checkbox';
$field = new $field_type();

Code I tested it with in PHP 5.3

$c = 'stdClass';

$a = new $c();

var_dump($a);

>> object(stdClass)#1 (0) {
}

Answer 2

This should work to instantiate a class with a string variable value:

$type = 'Checkbox'; 
$field = new $type();
echo get_class($field); // Output: Checkbox

So your code should work I'd imagine. What is your question again?

If you want to make a class that includes all extended classes then that is not possible. That's not how classes work in PHP.

Answer 3

If you are using a namespace you will need to add it even if you are within the namespace.

namespace Foo;

$my_var = '\Foo\Bar';
new $my_var;

Otherwise it will not be able to get the class.

Answer 4

You can also use reflection, $class = new ReflectionClass($class_name); $instance = $class->newInstance(arg1, arg2, ...);

Answer 5

just

$type = 'checkbox';
$filed = new $type();

is required. you do not need to add brackets

Answer 6

$field_type = 'checkbox';
$field = new $field_type;

If you need arguments:

$field_type = 'checkbox';
$field = new $field_type(5,7,$user);