Tag Archives: Google Chrome

Diving into Node.js – Introduction & Installation

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Why I Need Something Like Node.js?

First of all the use of some software is needed not because of itself, but because of the need of some specific functionality. In my case this was the need of real time news feed. Of course there is a way to make this without Node.js, as I’ll describe later in this post, but there are several disadvantages. However to begin from somewhere, let me explain what is Node.js.

Introducing Node.js

Perhaps the best way do describe what is Node.js is from its about page.

Node’s goal is to provide an easy way to build scalable network programs. In the “hello world” web server example above, many client connections can be handled concurrently. Node tells the operating system (through epoll, kqueue, /dev/poll, or select) that it should be notified when a new connection is made, and then it goes to sleep. If someone new connects, then it executes the callback. Each connection is only a small heap allocation.

…

In general Node is a program using the Google Chrome’s V8 JavaScript engine, which in turn is a program that can parse and execute code written in JavaScript. V8 is a very very interesting project itself. First of all from Google have developed this engine especially for one of his products – their browser Chrome. It pretends to be and by no means is one of the masterpieces of Google. It is fast and reliable engine, written in C++ and JavaScript, as Wikipedia’s page says. Actually this code is open source and can be embedded in whatever application written in C++. Thus you can have in your application a JavaScript engine. Continue reading Diving into Node.js – Introduction & Installation →

PHP: detecting mobile device

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HTTP_USER_AGENT

Beside that most of the responses of $_SERVER[‘HTTP_USER_AGENT’] may return, it appears that this is the most reliable way to track down a user agent with PHP. It is weird that most of the clients, i.e. Safari and Chrome will return something with Mozilla in it’s strings, but however it’s enough to track the “chrome” or “safari” sub strings.

All the examples bellow are from Mac OS X:

Firefox 3.6:

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6

Note: there are both Mozilla and Firefox sub strings!

Safari 4:

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_8; bg-bg) AppleWebKit/531.21.8 (KHTML, like Gecko) Version/4.0.4 Safari/531.21.10

Chrome:

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_5_8; en-US) AppleWebKit/532.9 (KHTML, like Gecko) Chrome/5.0.307.11 Safari/532.9

Note: Here they are Mozilla, Chorme and Safari!!!

Opera:

Opera/9.80 (Macintosh; Intel Mac OS X; U; en) Presto/2.2.15 Version/10.10

The day of mobile

Nowadays it’s normal to make a site with the presumption it will be visible from mobile. The war between Nexus One from Google and iPhone from Apple is just beginning and with all those devices with wide screens everything’s becoming more complicated.

User agent strings from Nexus One and iPhone

Both are weird, but both contain the keyword – “mobile” and that may help you make a check with something like this PHP snippet:

<?php
$mobile = !!(FALSE !== strstr(strtolower($_SERVER['HTTP_USER_AGENT']), 'mobile'));
?>

Storing JavaScript objects in html5 localStorage

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There is a rising new age of HTML5, which comes with very nice features as video tag and localStorage. What localStorage is? In fact we have been waiting for long time to have something that give us the power of storing more and more on the client side. That’s because the net is becoming larger and therefore heavy.

Imagine if you have the possibility to store large JSON returned from an AJAX call on the client. That’s now reality with the localStorage object in HTML5 and it can be accessed with something like this code:

localStorage.setItem(key, value);
alert(localStorage.getItem(key));

Can we store entire objects?

Yes there is a way extending a bit the logic of the code above. The localStorage in fact stores only strings, but what about arrays and objects. You can additionally use JSON global objects and its two methods – stringify and parse:

var a = JSON.stringify({name:'obj'});
alert(JSON.parse(a));

Do browsers support all that?

Of course … not! localStorage is supported by Firefox 3.5+, Chrome 2+, Safari 4+ and MSIE 8+. The solution is not to rely on browser version, but to check for object existence, and than to combine both techniques:

localStorage.setItem('a', JSON.stringify({ name : 'obj' }));
alert(JSON.parse(localStorage.getItem('a')));

YouTube and Vimeo goes HTML5 with video tag usage! Catch them up!

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What better example than that coming both from YouTube and Vimeo. Although video tag is not supported except under Safari and Chrome, that’s the future everyone’s going to embed sooner or later.

And if these “big players” are going that way, don’t hesitate to follow them! HTML5 is really what we as web developers were waiting for so long and even all of the problems during its standardization process it’s really cool there will be tags like video.

What YouTube is doing today, perhaps will seem normal to everyone tomorrow. However there are some questions still with no answer, as where the flash possibility to add ads into the player is going?! But we’re about to see great things from these two sites!

Just check out these two links:

Youtube HTML5

Vimeo