On December the 1st Mozilla released the new version 34 of it’s flagship browser Firefox. Alongside many GUI changes and security fixes the update disables SSLv3 and implements a few new JavaScript elements like WeakSets and JavaScript Template String. Learn all about the relevant new features here.

SSLv3 disabled

In version 34 Firefox disabled the support for SSLv3. This means that users visiting any Website with no higher standard than SSLv3 available will see a warning message inside Firefox. If you are a host websites it’s highly recommend that you update your webserver to support TLS 1.0 or higher. Google has accounced the same change in Chrome 39 and Microsoft has releases a fix to disable SSLv3 in Internet Explorer.

Further reading:

• Test any website for enabled SSLv3
• How to disable SSLv3 on most webservers
• The POODLE attach explained

JavaScript WeakSet

In the experimental WeakSets in JavaScript you can store weak references to objects. This means that these objects can get garbage collected while still be in your WeakSet. Let’s do a quick example:

var ws = new WeakSet();
var obj = {};
var foo = {};
 
ws.add(window);
ws.add(obj);
 
ws.has(window); // true
ws.has(foo); // false, foo has not been added to the set
 
ws.delete(window);
ws.has(window); // false, now
 
ws.clear();

Chrome and Opera already support this (version 38 and 25).

Further Reading:

• Documentation by Mozilla
• Understanding weak maps in JavaScript (releated)

JavaScript Template Strings

Using the experimental technologie you can embed expressions inside JavaScript strings. An example will tell you more than just words:

`string text`
 
`string text line 1
string text line 2`
 
`string text ${expression} string text`
 
tag `string text ${expression} string text`

This feature will also be available in Chrome 41.

Further Reading: 

• Documentation by Mozilla
• What are JS Template Strings?

DOM API matches()

You can now test if an element would be matched by a selector using element.matches(selector); in your JavaScript code. The method returns true for a match and false otherwise. No other browser supports this with the standard name though.

Further Reading:

• Documentation by Mozilla

Measure Performance in WebWorkers

In WebWorkers you can now use the new command performance.now() to get a timestamp in milliseconds since the worker was started. Great to measure performance for example! Currently this is supported in Firefox 34 and Chrome 33. It works like this:

t = performance.now();

Further Reading:

• Documentation by Mozilla
• Quick overview on HTML5Rocks

console.table

In Firefox 34 you can now print collections to the console using the new command console.table. This works on all kinds of collections including collections of objects.

Quick example:

// an array of strings
console.table(["apples", "oranges", "bananas"]);

will result in the console output:

This is not standard compatible and currently does not work in every browser! 

Further Reading:

• Documentation by Mozilla
• console.table in Google Chrome

We release these Browser News for every new Firefox, Chrome, Opera, Safari and Internet Explorer release so stay tuned!