KohanaPHP » Kohana v2.x

When running multiple events at once it's possible that Event::$data is reset before it can be discarded.

Take this scenario for example:

Two events:

site.inject
block.load

Attached callbacks:

site.inject -> load_site()
block.load -> load_blocks()
block.load -> load_menu_as_block()

The load_blocks callback will do a call to Event::run('site.inject');

$data = 'test';

Here's what happens when we fire Event::run('block.load', $data):

• call to function load_blocks -> Event::$data is 'test'
• inside load_blocks Event::run('site.inject') is fired -> Event::$data is empty
• call to function load_menu_as_block -> Event::$data is empty because it has been reset when site.inject was called

So bottom line is that when an event is fired in between two callbacks the Event::$data is being reset. This is a big problem when using a lot of events at once and passing data from one callback to another.

To solve this I made a very simple patch which keeps backwards compatbility with the current Event::$data method. Basically the $data variable passed to Event::run is passed directly (by reference) to the callback.

So instead of having this:

function test() {
echo Event::$data;
}

You use this:

function test(&$data) {
echo Event::$data;
}

Both methods will work and the second will preserve the $data var for each individual callback.

Please see the patch for how it works. It's only one line of code that is changed and everything is backwards compatible.