Home
>
Software
>
PHP On-The-Fly!

PHP On-The-Fly!

Introduction

PHP can be used for a lot of different things, and is one of the most powerful scripting languages available on the web. Not to mention it's extremely cheap and widely used. However, one thing that PHP is lacking, and in fact most scripting languages are, is a way to update pages in real-time, without having to reload a page or submit a form.

The internet wasn't made for this. The web browser closes the connection with the web server as soon as it has received all the data. This means that after this no more data can be exchanged. What if you want to do an update though? If you're building a PHP application (e.g. a high-quality content management system), then it'd be ideal if it worked almost like a native Windows/Linux application.

But that requires real-time updates. Something that isn't possible, or so you would think. A good example of an application that works in (almost) real-time is Google's GMail (http://gmail.google.com). Everything is JavaScript powered, and it's very powerful and dynamic. In fact, this is one of the biggest selling-points of GMail. What if you could have this in your own PHP websites as well? Guess what, I'm going to show you in this article.

How does it work?

If you want to execute a PHP script, you need to reload a page, submit a form, or something similar. Basically, a new connection to the server needs to be opened, and this means that the browser goes to a new page, losing the previous page. For a long while now, web developers have been using tricks to get around this, like using a 1x1 iframe, where a new PHP page is loaded, but this is far from ideal.

Now, there is a new way of executing a PHP script without having to reload the page. The basis behind this new way is a JavaScript component called the XML HTTP Request Object. See http://gmail.google.com for more information about the component. It is supported in all major browsers (Internet Explorer 5.5+, Safari, Mozilla/Firefox and Opera 7.6+).

With this object and some custom JavaScript functions, you can create some rather impressive PHP applications. Let's look at a first example, which dynamically updates the date/time.

Example 1

First, copy the code below and save it in a file called 'script.js':

var xmlhttp=false;

/*@cc_on @*/

/*@if (@_jscript_version >= 5)

// JScript gives us Conditional compilation, we can cope with old IE versions.

// and security blocked creation of the objects.

try {

xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");

} catch (e) {

try {

xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");

} catch (E) {

xmlhttp = false;

}

@end @*/

if (!xmlhttp && typeof XMLHttpRequest!='undefined') {

xmlhttp = new XMLHttpRequest();

}

function loadFragmentInToElement(fragment_url, element_id) {

var element = document.getElementById(element_id);

element.innerHTML = 'Loading ...';

xmlhttp.open("GET", fragment_url);

xmlhttp.onreadystatechange = function() {

if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {

element.innerHTML = xmlhttp.responseText;

}

xmlhttp.send(null);

}

Then copy the code below, and paste it in a file called 'server1.php':

And finally, copy the code below, and paste it in a file called 'client1.php'. Please note though that you need to edit the line that says 'http://www.yourdomain.com/server1.php' to the correct location of server1.php on your server.

Example 1

function updatedate() {

loadFragmentInToElement('http://www.yourdomain.com/server1.php', 'currentdate');

}

The current date is .

Now go to http://gmail.google.com and click on the button that says 'Update date'. The date will update, without the page having to be reloaded. This is done with the XML HTTP Request object. This example can also be viewed online at http://gmail.google.com

Example 2

Let's try a more advanced example. In the following example, the visitor can enter two numbers, and they are added up by PHP (and not by JavaScript). This shows the true power of PHP and the XML HTTP Request Object.

This example uses the same script.js as in the first example, so you don't need to create this again. First, copy the code below and paste it in a file called 'server2.php':

And then, copy the code below, and paste it in a file called 'client2.php'. Please note though that you need to edit the line that says 'http://www.yourdomain.com/server2.php' to the correct location of server2.php on your server.

Example 2

function calc() {

num1 = document.getElementById ('num1').value;

num2 = document.getElementById ('num2').value;

var element = document.getElementById('answer');

xmlhttp.open("GET", 'http://www.yourdomain.com/server2.php?num1=' + num1 + '&num2=' + num2);

xmlhttp.onreadystatechange = function() {

if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {

element.value = xmlhttp.responseText;

}

xmlhttp.send(null);

}

U se the below form to add up two numbers. The answer is calculated by a PHP script, and not with JavaScript. What's the advantage to this? You can execute server-side scripts (PHP) without having to refresh the page.

+ =

When you run this example, you can add up two numbers, using PHP and no reloading at all! If you can't get this example to work, then have a look on http://gmail.google.com to see the example online.

Any Disadvantages...?

There are only two real disadvantages to this system. First of all, anyone who has JavaScript turned off, or their browser doesn't support the XML HTTP Request Object will not be able to run it. This means you will have to make sure that there is a non-JavaScript version, or make sure all your visitors have JavaScript enabled (e.g. an Intranet application, where you can require JS).

Another disadvantage is the fact that it breaks bookmarks. People won't be able to bookmark your pages, if there is any dynamic content in there. But if you're creating a PHP application (and not a PHP website), then bookmarks are probably not very useful anyway.

Conclusion

As I've shown you, using two very simple examples, it is entirely possible to execute PHP scripts, without having to refresh the page. I suggest you read more about the XML HTTP Request Object (http://gmail.google.com) and its capabilities.

The things you can do are limitless. For example, you could create an extremely neat paging system, that doesn't require reloading at all. Or you could create a GUI for your PHP application, which behaves exactly like Windows XP. Just think about it!

Be aware though that JavaScript must be enabled for this to work. Without JavaScript this will be completely useless. So make sure your visitors support JavaScript, or create a non-JavaScript version as well.

About The Author

Dennis Pallett is a young tech writer, with much experience in ASP, PHP and other web technologies. He enjoys writing, and has written several articles and tutorials. To find more of his work, look at his websites at http://gmail.google.com http://gmail.google.com and http://gmail.google.com

http://gmail.google.com

custom home cleaning Lincolnshire ..

In The News:

Amazon Prime Day shoppers face threats from 120,000-plus scam websites as cybercriminals prepare phishing traps and malware ahead of the July sales event.

Fox News' AI Newsletter brings you the latest on this rapidly evolving technology.

The AEON humanoid robot tackles labor challenges with Nvidia AI, Microsoft Azure cloud and advanced spatial awareness, working alongside industry leaders Schaeffler and Pilatus.

Google's Ask Photos feature brings AI-powered searches to your photo library, letting you find memories with natural language queries while maintaining privacy controls.

The return of blue book exams emerges as universities fight widespread AI academic dishonesty and educators debate whether to ban AI tools or teach responsible usage.

Signs your phone might be hacked include strange behavior, unauthorized texts, battery drain and pop-ups, while protection involves updating software and avoiding public Wi-Fi.

Tokyo startup H2L has launched Capsule Interface technology enabling full-body robot control with muscle sensors, offering immersive remote operation.

The A.I. industry seems set for growing pains as Big Tech companies scramble for solutions to the medium's unprecedented strain on the power grid.

Fourth of July fireworks cause a 60% spike in lost pets, but GPS trackers and AI photo-matching services like Love Lost can help reunite missing dogs with their families.

Protect yourself from jugging, the rising crime by which thieves monitor ATM users and follow them to steal cash, with six practical safety tips to stay alert and secure.

U.S. airlines like Delta, American and United are selling your domestic flight records to government agencies through the little-known Travel Intelligence Program.

Autonomous robots from Uber Eats are rolling out across U.S. cities, featuring LIDAR sensors, secure compartments and all-weather operation for food and grocery delivery.

Costco has expanded into EV infrastructure with new ultra-fast charging stations that can charge most electric vehicles to 80% in 20-60 minutes while shoppers browse the warehouse.

The new Gemini Robotics On-Device AI allows robots to perform complex tasks without internet, offering enhanced privacy, reliability and adaptability for real-world use.

Protect yourself from Amazon phishing scams by spotting red flags like suspicious sender addresses and spelling errors while using Amazon's Message Center to verify communications.

GAC Group's new Govy AirCab flying car combines lightweight design with advanced safety systems and smart cabin technology to revolutionize city travel with an 18.6-mile range.

The Berkeley Humanoid Light (BHL) is a lightweight, open source humanoid robot that anyone can build using 3D-printed parts and off-the-shelf components.

Meta’s new AI chatbot is getting personal, and it might be sharing more than you realize.

A new threat targets both Android and iPhone users: SparkKitty, a powerful mobile malware strain that scans private photos to steal cryptocurrency recovery phrases and other sensitive data.

Thanks to a team at the University of California, Davis, there's a new brain-computer interface (BCI) system that's opening up real-time, natural conversation for people who can't speak.

Privacy risks are hiding in plain sight, as your personal data is likely being collected, tracked, and sold without your knowledge.

VenHub, a fully autonomous, AI-powered smart store just opened at the LAX/Metro Transit Center in Los Angeles.

A woman's Facebook account takeover reveals dangerous social engineering tactics and provides lessons on recovery, avoiding scams and enacting stronger security measures.

Shanghai engineers are using 432 walking robots to relocate a complex, preserving Shikumen architecture while creating space for a modern underground hub and cultural center.

Major healthcare data analytics firm Episource had a cybersecurity incident exposing 5 million patients' medical records and personal information in recent breach.

PHP On-The-Fly!

Software