lastguest/ev

A PHP Event emitter in only 103bytes

1.0.0 2014-10-17 23:45 UTC

Requires

• php: >=5.4

MIT

• Stefano Azzolini

• event
• micro
• emitter
• ev

README

A tweet-sized PHP Event emitter in only 103 bytes.

function ∑($n,$c=0){static$r;is_callable($c)?$r[$n][]=$c:@array_walk($r[$n],'call_user_func',$c?:[]);}

Warning: This is a pure proof of concept of a tweet sized event emitter

DO NOT USE IT IN PRODUCTION!

How to use

Bind handlers to event:

// Bind callback to event "init"
∑('init', function(){
    echo "Init event triggered!\n";
});

// Bind another callback to event "init"
∑('init', function(){
    echo "Second handler for init triggered!\n";
});

// Bind callback to event "debug.event" and listen to passed parameters
∑('debug.event', function($idx,$params){
    echo "Called debug.event[$idx] with parameters : ",print_r($params,true),"\n";
});

Trigger Events:

Calling an event with no parameters triggers all binded event handlers.

// Trigger `init`
∑("init");

Output:

Init event triggered!
Second handler for init triggered!

You can pass parameters to all handlers as an array :

// Trigger `debug.event` passing parameters
∑('debug.event',[1,2,'Hello, Friend.']);

Output:

Called debug.event[0] with parameters : Array
(
    [0] => 1
    [1] => 2
    [2] => Hello, Friend.
)

Commented source

function ∑ ($event_name, $callback=null){
    // The event handlers repository.
    static $event_handlers;
 
    if (is_callable($callback)) {

        // We are binding a callback to an event, add $callback to the
        // events handler repository.
        $event_handlers[$event_name][] = $callback;

    } else {

        // When $callback is not a callable, then we are triggering the event.
        // In this case, $callback will be our array of parameters to pass to event handlers 
        $params = $callback ? $callback : [];

        // Walk all handlers binded to event $event_name and invoke them with the
        // ($event_index, $params) parameters.
        array_walk($event_handlers[$event_name],'call_user_func',$params);
    }
} 

License (MIT)

Copyright (c) 2014 Stefano Azzolini

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.