"This widget ID is already used" when using "request"

Question

I need to check something with request on every page and load widget when data is correct.

The problem is strange - widget is loaded twice the second time I reload page.

var widgets = require("widget");
var self = require("self");
var tabs = require("tabs").on("ready", start_script);
var request = require("request").Request;

function start_script(argument) 
{
    request({
        // checking something
        url: "http://localhost/check.php",
        onComplete: function (response) 
        {
            if ( typeof widget == "undefined" )
            {
                // make widget
                var widget = widgets.Widget({
                    id: "xxxxxxxx",
                    label: "zzzzz",
                    contentURL: self.data.url("http://www.google.com/favicon.ico")
                });
            }
        }
    }).get();
}

It works for first page. After reloading it, it throws error: This widget ID is already used: xxxxxxxx.

Why does it load widget second time, even if I have if ( typeof widget == "undefined" )?

If I made it without request, everything is working great. What did request change?

Answer 1

Because variable widget is not yet defined / unknown in the if condition. You need to use proper scoping.

You can try:

var widgets = require("widget");
var self = require("self");
var tabs = require("tabs").on("ready", start_script);
var request = require("request").Request;
var widget; //define widget here so that it is visible in the if condition.

function start_script(argument) 
{
    request({
        // checking something
        url: "http://localhost/check.php",
        onComplete: function (response) 
        {
            if ( typeof widget == "undefined" )  //using the variable here
            {
                // make widget
                widget = widgets.Widget({
                    id: "xxxxxxxx",
                    label: "zzzzz",
                    contentURL: self.data.url("http://www.google.com/favicon.ico")
                });
            }
        }
    }).get();
}

or

Check for the presence of a widget with id xxxxxxxx inside the if condition.