Error: Call to undefined function wire()

[Tom.]

// create your hook function
function myHook(HookEvent $e) {
    echo "30 Minutes have passed!";
}
// add a hook to your function:
wire()->addHook('LazyCron::every30Minutes', null, 'myHook');

I'm trying to use above in my template file, however I'm getting the error:

Error: Call to undefined function wire() 

Any ideas why this isn't working?

Edit:

$wire->addHook seems to have got it. Is this still correct syntax? 

[AndZyk]

Hello Tom.,

personally I never worked with hooks (although it is on my todo list). But I think the addHookMethod in the API reference is related to your question.

Available since version 3.0.16. Added as an alias to addHook() for syntactic clarity, previous versions can use addHook() method with same arguments.

Regals, Andreas

[LostKobrakai]

addHookMethod !== addHook, but wire() is namespaced as ProcessWire/wire() since 3.0.

[Tom.]

addHookMethod !== addHook, but wire() is namespaced as ProcessWire/wire() since 3.0.

I've used $wire->addHook, it seems to be working, however I was just wondering if this was incorrect and that I should use the namespaced wire(). 

[LostKobrakai]

$wire and ProcessWire/wire() return the exact same object, but $wire is only available in template/bootstrap context. Depending on where you're trying to use wire() it might get compiled and should work as before. 

[ceberlin]

Just for clarification, the "\" backslash works better:

ProcessWire\wire()