JavaScript Hooks and Filters

javascript.hooks-filters.js

/*
 * Source: http://stackoverflow.com/questions/20131168/jquery-javascript-hooks/20132960#20132960
 * Gist: https://gist.github.com/JoeSz/6aa061ff48eaf1af658d3adf9d71ec37
 * 
 * JavaScript Hooks
 * Essentially it's a place in code that allows you to tap in to a module to either provide different 
 * behavior or to react when something happens.
 * (http://stackoverflow.com/questions/467557/what-is-meant-by-the-term-hook-in-programming/467568#467568)
 *
 * or as Wikipedia says:
 * In computer programming, the term hooking techniques used to alter or augment the behavior of 
 * applications, or of other software components by intercepting function calls or messages or 
 * events passed between software components. Code that handles such intercepted function calls, 
 * events or messages is called a "hook".
 */
var filter = {

    filters: {},

    add: function ( tag, filter ) {
        ( this.filters[tag] || ( this.filters[tag] = [] ) ).push( filter );
    },

    apply: function (tag, val, def) {
        try {
            if ( this.filters[tag] ) {
                var filters = this.filters[tag];
                for( var i = 0; i < filters.length; i++ ){
                    val = filters[i](val);
                }
            } else if ( def ) {
                val = def;
            }
            return val;
        } catch ( err ) {
            console.log( err );
        }

    },

    remove: function( tag ) {
        if( this.filters[tag] ){
            delete this.filters[tag];
        }
    }
};

// Then to add a filter:
filter.add('modify_name', function(name){
    name = 'MR. ' + name;
    return name;
});

// And to apply the filters:
// Default value if "modify_name" filter and "name" value is not exist, false, 0, null or empty
name = filter.apply('modify_name', name, 'default-value');

// Then to add a "hook":
// (Hook as filter without return a value)
filter.add('modify_hook_name', function(){
    // Your code here
});

// Remove filter/"hook"
filter.remove('modify_name');

// And to run the "hook"
filter.apply('modify_hook_name');

// Check if filter exist
 if ( typeof filter !== 'undefined' ) filter.apply( 'hook-name' );