Invokes a user handler upon calling a function or a class method

function fb_intercept(
  string $name,
  mixed $handler,
  mixed $data = NULL,
): bool;

If this handler returns FALSE, code will continue with original function. Otherwise, it will return what handler tells. The handler function looks like "intercept_handler($name, $obj, $params, $data, &$done)", where $name is original function's fully-qualified name ('Class::method'), $obj is $this for an instance method call or null for static method call or function calls, and $params are original call's parameters. $data is what's passed to fb_intercept() and set $done to false to indicate function should continue its execution with old function as if interception did not happen. By default $done is true so it will return handler's return immediately without executing old function's code. Note that built-in functions are not interceptable.


  • string $name - The function or class method name to intercept. Use "class::method" for method name. If empty, all functions will be intercepted by the specified handler and registered individual handlers will be replaced. To make sure individual handlers not affected by such a call, call fb_intercept() with individual names afterwards.
  • mixed $handler - Callback to handle the interception. Use null, false or empty string to unregister a previously registered handler. If name is empty, all previously registered handlers, including those that are set by individual function names, will be removed.
  • mixed $data = NULL - Extra data to pass to the handler when intercepting


  • bool - - TRUE if successful, FALSE otherwise