Interfaces

Declaring an interface is just like declaring any other class with the exception of a couple of steps. The first of these steps is declaring all of its methods as abstract, which can be done through using the PHP_ABSTRACT_ME() macro:

static function_entry php_sample3_iface_methods[] = {
 PHP_ABSTRACT_ME(Sample3_Interface, workerOne, NULL)
 PHP_ABSTRACT_ME(Sample3_Interface, workerTwo, NULL)
 PHP_ABSTRACT_ME(Sample3_Interface, workerThree, NULL)
 { NULL, NULL, NULL }
};

Because these methods are abstract, no implementation methods need exist. You're already prepared for the second step, which is registration. Like registration of a real class, this begins with calls to INIT_CLASS_ENTRY and zend_register_internal_class.

When the class entry is available, the last step is to mark the class as an interface so that it can be implemented:

zend_class_entry *php_sample3_iface_entry;
PHP_MINIT_FUNCTION(sample3)
{
 zend_class_entry ce;
 INIT_CLASS_ENTRY(ce, "Sample3_Interface",
 php_sample3_iface_methods);
 php_sample3_iface_entry =
 zend_register_internal_class(&ce TSRMLS_CC);
 php_sample3_iface_entry->ce_flags|= ZEND_ACC_INTERFACE;
 ...

 

Implementing Interfaces

Assuming you wanted your Sample3_SecondClass class to implement the Sample3_Interface interface, you'd need to implement each of the abstract methods listed as part of the interface within your class:

PHP_METHOD(Sample3_SecondClass,workerOne)
{
 php_printf("Working Hard.
");
}
PHP_METHOD(Sample3_SecondClass,workerTwo)
{
 php_printf("Hardly Working.
");
}
PHP_METHOD(Sample3_SecondClass,workerThree)
{
 php_printf("Going wee-wee-wee all the way home.
");
}

Then declare them in the php_sample3_sc_functions list:

PHP_ME(Sample3_SecondClass,workerOne,NULL,ZEND_ACC_PUBLIC)
PHP_ME(Sample3_SecondClass,workerTwo,NULL,ZEND_ACC_PUBLIC)
PHP_ME(Sample3_SecondClass,workerThree,NULL,ZEND_ACC_PUBLIC)

And finally, declare that your newly registered class implements the php_sample3_iface_entry interface:

PHP_MINIT_FUNCTION(sample3)
{
 zend_class_entry ce;
 /* Register Interface */
 INIT_CLASS_ENTRY(ce, "Sample3_Interface",
 php_sample3_iface_methods);

 php_sample3_iface_entry =
 zend_register_internal_class(&ce TSRMLS_CC);
 php_sample3_iface_entry->ce_flags|= ZEND_ACC_INTERFACE;
 /* Register Class implementing interface */
 INIT_CLASS_ENTRY(ce, PHP_SAMPLE3_SC_NAME,
 php_sample3_sc_functions);
 php_sample3_sc_entry =
 zend_register_internal_class(&ce TSRMLS_CC);
 php_sample3_register_constants(php_sample3_sc_entry);
 zend_class_implements(php_sample3_sc_entry TSRMLS_CC,
 1, php_sample3_iface_entry);
 return SUCCESS;
}

If Sample3_SecondClass implemented other interfaces, such as ArrayAccess, its class entries could be added as additional parameters to zend_class_implements() by incrementing the one parameter to match the number of interfaces passed.

zend_class_implements(php_sample3_sc_entry TSRMLS_CC,
 2, php_sample3_iface_entry, php_other_interface_entry);