javascript based actions/filters library inspired by WordPress
I often work with WordPress as a developer and I love that it has actions/filters, they are very useful; hence, I decided to make the same functionality available in my JS apps too.
It requires jQuery or Zepto. Yes, I could write it to work without jQuery, but $.map() is sooo handy :).
Functionality is pretty similar to that of the WordPress actions/filters system. For those who are not familiar with it, I would suggest reading this to understand the difference between actions and filters: http://wp.tutsplus.com/tutorials/the-beginners-guide-to-wordpress-actions-and-filters/
To sum up, with actions, you don't expect data to be modified or returned, you just want to execute certain functions when action is triggered (like events). Filters on the other hand modify the passed data and return it.
Basic action example:
function alert_the_name( name ) {
alert( name );
}
JSAF.add_action( 'trigger_name', alert_the_name );
JSAF.do_action( 'trigger_name', [ 'Ante' ] );
// alerts "Ante"
Basic filter example:
function append_surname( name ) {
return name + " Sepic";
}
JSAF.add_filter( 'full_name', append_surname );
JSAF.apply_filters( 'full_name', [ 'Ante' ] );
// returns "Ante Sepic"
Easy, right?
Normally, actions/filters are executed in the order they are defined in. But what if we want to execute two actions/filters in custom order?
No problem:
function append_random( text ) {
return text + " is your name!";
}
function append_surname( name ) {
return name + " Sepic";
}
JSAF.add_filter( 'full_name', append_random, 11 ); // we defined priority as "11", and since the default priority is 10, this filter will be applied after the one we are defining in the next line
JSAF.add_filter( 'full_name', append_surname ); // as usual
JSAF.apply_filters( 'full_name', [ 'Ante' ] );
// returns "Ante Sepic is your name!"
It's very easy to pass variables to your functions
Basically, what you do is (as a second parameter of apply_filters/do_action) specify array of values you are passing, and then in the function you catch them in the order you defined them.
Example:
JSAF.apply_filters( 'hook_name', [ 'Ante', 'Sepic', 'is my name' ] );
and you would catch it in your function like this:
function random_string( name, surname, text ) {
return name + surname + text;
}
Aaah, the infamous this. You can set what this wil be inside your function by passing it as a fourth parameter of the add_action/add_filter:
var person = {
name: 'Ante',
shoutMyName: function() {
alert( this.name );
}
}
JSAF.add_action( 'shout_names', person.shoutMyName, 10, person );
JSAF.do_action( 'shout_names' );
// alerts "Ante"
You can easily remove filters/actions you or other people have defined. All you need to know is hook, function name and priority.
...
JSAF.remove_filter( 'full_name', append_surname, 10 ); // we could've just left out the priority here since it defaults to 10
JSAF.apply_filters( 'full_name', [ 'Ante' ] );
// returns "Ante is your name!"
For actions, use JSAF.remove_action with the same signature
JSAF is licensed under MIT licence, which basically means you can do anything with it (I would appreciate it if you didn't remove the link to this github page from the js source).