IE script error with my jQuery plugin

Question

I cannot seem to figure out I am getting the following error in IE 8 (only IE version I've tested so far). The script runs fine in all (chrome, ff, safari) other browsers I've tested. What am I doing wrong?

Error:

Message: Object doesn't support this property or method Line: 52 Char: 29 Code: 0 URI: http://www.ntierdesign.com/jquery/livetwitter/Scripts/jquery.liveTwitter.js

Message: Object doesn't support this property or method Line: 1 Char: 1 Code: 0 URI: http://twitter.com/status/user%5Ftimeline/bloomsdayreg.json?count=3&callback=jsonp1251868075768&%5F=1251868075882

Example:

Hopefully I won't cap out my twitter api rate limit too fast, but you can view an example of the page here http://ntierdesign.com/jquery/livetwitter/

Answer 1

You are having this error because the version of IE that you are using doesn't implements Array/indexOf, which has been introduced in JavaScript 1.6.

However you could add the indexOf method to the Array prototype if it doesn't exists, for compatibility.

This is the implementation that Firefox uses internally:

if (!Array.prototype.indexOf) {
  Array.prototype.indexOf = function(elt /*, from*/) {
    var len = this.length >>> 0;

    var from = Number(arguments[1]) || 0;
    from = (from < 0)
         ? Math.ceil(from)
         : Math.floor(from);
    if (from < 0)
      from += len;

    for (; from < len; from++) {
      if (from in this &&
          this[from] === elt)
        return from;
    }
    return -1;
  };
}

Check with IE this example of your page, having the compatibility function added, runs without problems...

Answer 2

The error points directly to line 52, char 29, which is the .indexOf method on array.

this method is not implemented on IE's javascript - hence the error.

luckily there are tons of workarounds on the web, eg. link text

Answer 3

Just noticed that if you want to use a native jQuery approach, you can use the inArray function in the utilities class. jQuery inArray Documentation

Answer 4

You might want to reconsider the name, I've already released a similar plugin. :)

http://github.com/elektronaut/jquery.livetwitter/tree/master