Emulate PHP $_GET

[metaw3]

Hello. First post here. Just sharing fresh code.

I tried to reply to this thread:
http://www.dynamicdrive.com/forums/s...ad.php?t=11883
but it seemed locked: "you don't have the privileges to reply..."

That's the only page I found on the web almost about what I was playing with last night: emulating PHP $_GET with no other concern than making it readable and usable for a PHP developer not used to JS. So again: common JS coding guidelines as well as performance were not a concern. It's just an expermiment for fun.

Online: http://www.christianfecteau.com/echo/$_GET/$_GET.html
and attached...

$_GET = {};  // emualte PHP $_GET
(function(){ // by Christian Fecteau
	var $params = location.search.substr(1).split('&');
	for (var $i = 0; $i < $params.length; $i++) {
		var $pair = $params[$i].split('=');
		if ($pair[0])
			$_GET[$pair[0]] = unescape($pair[1] || "");
	}
})();

[Twey]

Don't use $ for identifiers in JS -- it's reserved for machine-generated identifiers only. In addition, escape() and unescape() are deprecated: encodeURIComponent() (in this case) should be used instead. Too, order isn't important here so we can iterate backwards and squeeze a few more cycles out of this algorithm. Try:

var Functional = {
  map: function(f, a) {
    for(var r = [], i = a.length - 1; i >= 0; --i)
      r[i] = a[i];
    return r;
  },

  invertArgs: function(f, args) {
    return function(o) {
      return f.apply(o, args);
    };
  },

  combine: function(a, b) {
    return function() {
      return a(b.apply(null, arguments));
    };
  }
};

function Hash(obj) {
  if(obj)
    this.update(obj);
}

Hash.prototype = {
  update: function(o) {
    for(var x in o)
      if(o.hasOwnProperty(x))
        this[x] = o[x];
    return this;
  }
};

Hash.fromArray = function(a) {
  for(var r = new Hash(), i = a.length; i >= 0; --i)
    r[a[0]] = r[a[1]];
  return r;
};

var _GET = (function(loc) {
  return Hash.fromArray(
    Functional.map(
      Functional.combine(
        function(a) { return Functional.map(decodeURIComponent, a); },
        Functional.invertArgs(loc.split, "=")),
      loc.split(/[&;]/)));
})(location.search);

[jscheuer1]

In addition, escape() and unescape() are deprecated: escapeURIComponent() (in this case)

Isn't that encodeURIComponent()?

Anyways, escape and unescape are fine, especially if you want backward compatibility. However the right way would I suppose be to write one's own functions employing escape and unescape for use only when the newer functions aren't native to the user agent.

I still like mwinter's simple method though:

function getQueryValue(name) {
    var match = (new RegExp('[?&;]' + name + '=([^&;#]*)')).exec(document.URL);

    return match ? unescape(match[1]) : null;
}

[Twey]

Isn't that encodeURIComponent()?

Yep. *furtive edit*

Anyways, escape and unescape are fine, especially if you want backward compatibility.

They break for non-ASCII characters.

I still like mwinter's simple method though:

Mike's is good, but not the same as what was being asked for here. Also, I prefer to write general code and then apply it to a given situation, rather than write code just for one situation.