CODEWITHSUNDEEP
javascriptfirefoxfirefox-addonglobal-variables
Ryan
Ryan

Reputation: 10049

javascript: namespace pollution

I am trying to submit my addon to the mozilla site but I am getting this damn warning:

enter image description here

The code (in mf_options.js) is pretty simple (and i think the problem is only between the "start storage" and "end storage":

// start Storage
var url = "http://mafiaafire.com";
var ios = Components.classes["@mozilla.org/network/io-service;1"]
          .getService(Components.interfaces.nsIIOService);
var ssm = Components.classes["@mozilla.org/scriptsecuritymanager;1"]
          .getService(Components.interfaces.nsIScriptSecurityManager);
var dsm = Components.classes["@mozilla.org/dom/storagemanager;1"]
          .getService(Components.interfaces.nsIDOMStorageManager);
var uri = ios.newURI(url, "", null);
var principal = ssm.getCodebasePrincipal(uri);
var storage = dsm.getLocalStorageForPrincipal(principal, "");
// end Storage



function display_blocked_list1() {

  var list = storage.getItem('domain_list_original');
  if (list !== undefined) {

    var strSingleLineText = list.replace(new RegExp( " ", "g" ),    "<br>"  );

    var status = document.getElementById("div1");
 status.innerHTML = strSingleLineText;
   }

  var list2 = storage.getItem('domain_list_redirect');
  if (list2 !== undefined) {

    // Strip out all line breaks.
    var strSingleLineText2 = list2.replace(new RegExp( " ", "g" ),  "<br>"  );

    var status2 = document.getElementById("div2");
 status2.innerHTML = strSingleLineText2;
   }


  var list3 = storage.getItem('list_expiry_date');

  if (list3 !== undefined) {



var dateArray = list3.split(",");
var future_date = new Date(dateArray[0],dateArray[1],dateArray[2]);
future_date.setDate(future_date.getDate()+2);

    var status2 = document.getElementById("div3");
 status2.innerHTML = future_date;

  }
// ##################################################

}

Upvotes: 3

Views: 961

Answers (3)

Blender
Blender

Reputation: 298582

The problem is that you are using too many global variables, those defined outside of a function.

Imagine this scenario: my addon, Foo, uses a variable called sheep.

var sheep = 10;

Your addon, Bar, uses a variable also called sheep:

var sheep = 20;

When I go to access sheep, how can I be assured your addon hasn't modified it? This is the same reason addons use anonymous functions foo = function() {, because they are local.

To make you global variables more local, wrap your whole script in an anonymous function:

(function() {
  var sheep = 10;
}());

Now, you can do whatever you wish with sheep and it will be local. Keep in mind, though, that you'd need some better scaffolding if you plan on making your application more complex. This method isn't completely bulletproof or scalable...

Upvotes: 0

Felix Kling
Felix Kling

Reputation: 817238

You should definitely have a look at the link. However I also got this message and I'm fairly sure my code does not contain any (polluting) global variables.

But if this is exactly the code you use, then any function and variable you declare will be global. In its simplest case, wrap the code in an anonymous function call:

(function() {
    // your code here
}());

If you need a global variable, because you have to call function from XUL elements, make sure you only have one. Create it inside the function call above with

window.YourPluginNamespace = {
    // all functions or "subspaces" here
};

Upvotes: 3

Mike Samuel
Mike Samuel

Reputation: 120586

Wrap your code in a function envelope so your vars are local to that function body, and explicitly attach anything you want global to the global object.

(function (global) {

  // your code here

  global.myGlobalVar = myVar

}(this));

Upvotes: 2

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