A simple JavaScript Sub/Pub

bups.js

/* ----------- simple sub/pub --------------
 * -- Author: Mindon Feng http://mindon.github.com
 * -- Usage:
 * BuPS.subscribe("event-string", function(data, cmd){});
 * BuPS.publish("event-string", data);
 */

var BuPS={}, _DEBUG=false;
;(function(){
var cmds = {};

function debug() {
  var cl = !!window.console;
  if(cl && console.debug)
    console.debug.apply(console, arguments);
  else if(cl && console.log) 
    console.log.apply(console, arguments);
  else
    alert(Array.prototype.slice.apply(arguments).join(" "));
}

function clone(obj) { // copy data
    if (!obj || "object" != typeof obj) return obj;
    
    if (obj instanceof Number) {
      return 0 + obj

    } else if (obj instanceof Boolean) {
      return obj == false ? false: true;  
    
    } else if (obj instanceof String) {
      return obj.toString();
    
    } else if (obj instanceof Array) {
        var copy = [];
        for (var i = 0, len = obj.length; i < len; i++) {
            copy[i] = (!obj[i] || "object" != typeof obj[i]) ? obj[i] : clone(obj[i]);
        }
        return copy;
    
    } else if (obj instanceof Date) {
        return new Date(obj.getTime());
    
    } else if (obj instanceof Object) {
        var copy = {};
        for (var attr in obj) {
            if (obj.hasOwnProperty(attr)) {
              copy[attr] = (!obj[attr] || "object" != typeof obj[attr]) ? obj[attr] : clone(obj[attr]);
            }
        }
        return copy;
    }
}

function subscribe(cmd, fn) {
  if(typeof fn != "function") {
    _DEBUG && debug("[SUBSCRIBE] WARNING:", cmd, typeof fn, subscribe.caller.caller);
    return false;
  }
  if(cmd.indexOf(',')>0) {
    var c = cmd.split(/\s*,\s*/);
    for(var i=0; i<c.length; i++){
      c[i] && subscribe(c[i], fn);
    }
    return c.length;
  }
    
  if(!cmds[cmd]) {
    cmds[cmd] = [fn];
  } else {
    var i = cmds[cmd].indexOf(fn);
    if(i < 0) { // insert
      cmds[cmd].push(fn);

    } else { // update
      _DEBUG && debug("[SUBSCRIBE] REPLACED:", cmd, i);
      cmds[cmd][i] = fn;
    }
  }

    var checkRxp = new RegExp("publish\\(\\s*[\'\"]" + cmd.replace(/\./g, "\\.") + "[\'\"],");
    if(checkRxp.test(fn.toString())) {
      debug &&debug("[SUBSCRIBE] FATAL: Suspicion loop calling publish & subscribe! // " + cmd);
    }
}

function publish(cmd, data) {
  var d = cmds[cmd];
  if(!d || d.length == 0){
    _DEBUG && debug("[PUBLISH] EMPTY:" + cmd);
    return false;
  }

  var ok = 0;
  _DEBUG && debug("[PUBLISH] "+cmd+": listener count = " +d.length);
  for(var k=0, kmax=d.length; k<kmax; k++) {
    try {
      if(d[k] && typeof d[k] == "function") {
        (d[k])(clone(data), cmd);  // sync
        ok++;
      } else {
        _DEBUG && debug("[PUBLISH] ERROR:", typeof d[k]);
      }
    } catch(e) {
      _DEBUG && debug("[PUBLISH] FAILED:", "cmd:" +cmd, ", error: " +e.message, ", func: " +d[k]);
    }
  }
  _DEBUG && debug("[PUBLISH] RESULT:", cmd +" = ", ok + "/" + d.length);

  // remove undefined fn
  var k = d.length -1;
  while(k > 0) {
    if(d[k] == undefined) {
      d.splice(k, 1);
    }
    k -= 1;
  }
}

function unsubscribe(fn) {
  for(var k in cmds) {
    var i = cmds[k].indexOf(fn);
    if(i > -1) {
      cmds[k][i] = undefined;
    }
  }
}

// export api
BuPS.subscribe = subscribe;
BuPS.publish = publish;
BuPS.unsubscribe = unsubscribe;
//bups.clone = clone;
//simple pubsub
})();