@namakuherman

In OOP we will always find keywords Public, Private, and Protected. These three things are used to determine the visibility of members (properties and functions) that are characteristic of object-oriented programming. Are members globally accessible (public) or accessed by its class (private) or accessed by the class and subclasses. Meanwhile, if the procedural programming members can only be accessed globally.

In public visibility, a method or property can be accessed globally. That means it can be accessed on the inside and outside of class or in other words the properties and functions are known globally. In OOP PHP tutorial for Beginers previously, we have made $objPeople which the visibility of properties and function are public.

This is another example of class with public visibility :

Script 1.

<?php
class student {
    public $sid;
    public $name;
    public $point;

    public function processPoint () {
    echo "Students with sid $this->sid <br />";
    echo "name $this->name <br />";
    echo "get point $this->point";
    }
}
$objStudent = new student();
$objStudent->sid = '3310901051';
$objStudent->name = 'Hermanto';
$objStudent->point = 90;
$objStudent->processPoint();
?>

And this is the result looks like in browser

If public can accessed by global  then private visiblity means that the member (method or property) in a class are accessible only within its own class.

Let's modify the script at class student by changing the property visibility to be private.

Script 2

<?php
class student {
    private $sid;
    private $name;
    private $point;

    public function processPoint () {
    echo "Students with sid $this->sid <br />";
    echo "name $this->name <br />";
    echo "get point $this->point";
    }
}
$objStudent = new student();
$objStudent->sid = '3310901051';
$objStudent->name = 'Hermanto';
$objStudent->point = 90;
$objStudent->processPoint();
?>

If we run the script 2, it will display an error message because the property sid, name and points have private visibility, so that the data accessed by outside of class can not be done. So how do the private property that is accessible outside of class so that it can be used by objects that need it? The solution is to use the function setter and getter.

Setter is used to create a (set of) value for a property. This function is generally used for properties that have private and protected visibility. Setter is often used to validate incoming data before the data is loaded on a property. While the getter is used to generate (get) a value of the member public, private, or protected from the result.

How to access private member with that function?

Script 3

<?php
class student {
    private $sid;
    private $name;
    private $point;

    function setSid($x) {
        $this->sid=$x;
    }
    function setName($x) {
        $this->name=$x;
    }
    function setPoint($x) {
        $this->point=$x;
    }
    function getSid() {
        return $this->sid;
    }
    function getName() {
        return $this->name;
    }
    function getPoint() {
        return $this->point;
    }
    function Point () {
    echo "Students with sid $this->sid <br />";
    echo "name $this->name <br />";
    echo "get point $this->point";
    }
}
$objStudent = new student();
$objStudent->setSid('3310901051');
$objStudent->setName('Hermanto');
$objStudent->setPoint(90);
$objStudent->point();
?>

In the script above, we use function setters and getters for each property that has a private visibility. Making the value of the function by taking the value setter and getter done by function. In the getter is used "return" value because the getter will return the value of the property taken by the data.

Note how to calling the property after instancing $objStudent, calling the property is done by calling the names function with ($objStudent-> setSid()). Although become longer code lines, but more OOP recommend this method for accessing a Member.

If the script is run in the browser then the result will be the same as the picture below :

<?php
class student {
    protected $sid;
    protected $name;
    protected $point;

    public function processPoint () {
    echo "Students with sid $this->sid <br />";
    echo "name $this->name <br />";
    echo "get point $this->point";
    }
}
$objStudent = new student();
$objStudent->sid = '3310901051';
$objStudent->name = 'Hermanto';
$objStudent->point = 90;
$objStudent->processPoint();
?>

If the script is run in browser then the result will error : cannot access protected property.

The error occurred because the protected class can only be accessed by its class and subclasses. For more detailed discussion of inheritance protected in subclasses will be explained on the nexy tutorials on The Inheritance.

Are you questioning What is AJAX, and How to Use it With jQuery? To answer the long question, we need to start it from the meaning of AJAX. No, it is not football club from Holland but AJAX is asynchronous JavaScript and XML. People use AJAX to load data from a server and then display it on the webpage without the need to reload the page. With AJAX, you will see only part of the website is changed while the other remain the same because the page is not refreshed. If you still confuse, you can open your Gmail and switch from “inbox” to “sent mail”. You will see the content is different but the page is the same. AJAX call is something you do behind the scene.

So, what is the benefit of AJAX?  
- Minimize Bandwidth Usage
AJAX can work without reloading page, so you don't need to refresh and excedded your bandwidth usage.
- Faster
Facebook is one from many website that using AJAX. When new notifications coming, it will show you the alarm or notification info in right top position of your facebook page, that's work by AJAX. You can imagine how it works without AJAX, you don't know if there are new notifications coming, you should refresh your facebook page to know that.
- User Friendly
You don't need to refresh the page if you want to see the changes.

Now that you know what AJAX is, we are half way. To complete the answer for What is AJAX, and How to Use it With jQuery we need to continue with it application with jQuery. If you wonder why jQuery, people love it because jQuery supports AJAX in fantastic way. Even more, you will find the implementation is very easy. One important thing is to tell the browser whether to catche AJAX or not, especially since different browsers will behave in different ways.

Here is how to do it :

This is the example :

Example of $.ajax with success is:

Now you have the answer for What is AJAX, and How to Use it With jQuery. This is the time to apply it and see what happen.

Object oriented programming has begun in era of PHP3, but still simple and not perfect. While web technologies and cloud computing grows up then PHP 5 has been developed to support full OOP. OOP become popular among web programmers. For example, many CMS like Joomla, WordPress, PrestaShop and Moodle are built with OOP. Furthermore, trend use of Frameworks like Yii Framework, Codelgniter, Zend, CakePHP and etc. All of them also built with OOP.

So, how to implement OOP in PHP? To answer this question, first you must have mindset when using OOP "Everything is an Object". Object is the "main actor" in OOP. So when you developing a website in PHP you should thinking about Object. You should think how interaction between obejcts can solve the problem.

Now, let's  implementing OOP in PHP, There are four basic terms you should be known in OOP. They are Object, Class, Property and Method. And here they are :

A. Class

B. Method

C. Instance Object

D. Set Properties

Picure 1. Set Properties

E. Running the Function

Picture 2. Call the Function

To start learning PHP, you should have basic knowladge of HTML. There are 2 ways to create PHP file, which embadded script and non embadded script. Embadded script is PHP that placed in HTML script. While non embadded script is PHP script wrote without placed in HTML script. Here's the difference between embadded script and non embadded script when displaying string using echo command.

Embedded Script
<html>
<head>
<title>WebDev777.COM - Web Development Research and Tutorial</title>
</head>
<body>
<?php 
echo "WebDev777.COM - Web Development Research and Tutorial"
?>
</body>
</html>

Non Embadded Script

Or
<?php
echo "<html>";
echo "<head>";
echo "<title>";
echo "WebDev777.COM - Web Development Research and Tutorial";
echo "</title>";
echo "</head>"; echo "<body>";
echo "WebDev777.COM - Web Development Research and Tutorial";
echo "</body>";
echo "</html>";
?>

Or
<html>
<head>
<title>WebDev777.COM - Web Development Research and Tutorial</title>
</head>
<body>
</body>
</html>

<?php
echo "WebDev777.COM - Web Development Research and Tutorial"
?>

Explanation

In embedded script, the code placed in anywhere in html script, whereas non embedded script is php script wihout html.

After knowing how to create php file, now we go to the main lesson, how to send data via POST and GET parameters. PHP has 2 method that can be used for send data from client (browser) to the server, and that they are, POST and GET.

POST method is used to transmit data from client to server where the data will sent via http header. For an example we create an input form with name forminput.php. The script is below :

<html>
<head>
<title>WebDev777.COM - Web Development Research and Tutorial</title>
</head>
<body>
<form section method="POST" action="tInput.php">
Title : <input type="text" name="title"> <br>
Editor : <input type="text" name="editor"> <br>
Publisher : <input type="text" name="publisher"> <br>
<input type="submit" value="Submit">
</form>
</body>
</html>

And this is the forms looks in browser

Picture 1. forminput.php

The script with red color using the post method to transmit data of title, editor, and publisher to tinput.php. (action = destination) that will using $_POST command to get the data sent. Because the parameters will be sent to tinput.php then we must create tinput.php.

In the recent web design tutorial we have learnt first HTML How To Make Table and now we will learn about Forms in HTML. What is form?? Maybe you ever seen a form in real life, such at psycho test or collage registration. And for example look at a simple psycho test form below.

The registration form in picture 2 is use for collecting data from the registers. Same as picture 2 the form in website is use for collecting data that inputed from form. This is closely related with PHP and Database. So, because the function of form is use for inputing data then to create an HTML form we can use <input> tag.

In picture 2 there are option to identify the participant, like Mr., Mrs., or Ms. and the value for inputed is not charracter but check symbol. In HTML we can use checkboxes element. There are many elements in HTML form, the most common input types are described below :

Text Fields

Text Field is the most frequently used elements.

<form>
First name: <input type="text" name="firstname"><br>
Last name: <input type="text" name="lastname">
</form>

And this the HTML code above looks in browser:

<input type="password"> defines a password field:

<form>
Password: <input type="password" name="pwd">
</form>

And how it looks like in browser

Password:

The character in passfield are masked (shown as asterisks or circle)

Radio Buttons
<input type="radio"> defines a radio button. Radio buttons let a user select ONLY ONE of a limited number of choices:

<form>
<input type="radio" name="option" value="Yes">Yes<br>
<input type="radio" name="option" value="No">No
</form>

And how it looks like in browser

Yes
No

Checkboxes
<input type="checkbox"> Let a user choose more then on option.

<form>
<input type="checkbox" name="vehicle" value="Bike">I have a bike<br>
<input type="checkbox" name="vehicle" value="Car">I have a car 
</form>

And how it looks like in browser

I have a bike
I have a car

Submit Button
Submit button is used to send data to the server, data sent to the specified form action

<form name="input" action="http://apps.webdev777.com/code/sentmail.php" method="get">Email: <input type="text" name="user"><input type="submit" value="Submit"></form>

How it looks like in browser

Email:

If you type your email in the field above and click "Submit" button, you will receive an email from herman@webdev777.com

Many people says that HTML stands for Hyper Text Markup Language. But I have my own stands for HTML. In my experience when I begn autodidactiong HTML I learn how to make the layout. And I find the simple way to design the layout is using table tags. If you looking the web layout without fill (color and picture), you will got it. Look at the table below :

1/A	B	C	D	E	F
2
3
4
5
6
7
8

The picture 1 shows the simple table that has 6 colomns and 8 rows. Let's make a little changing. Look at the table 2 below.

HEADER
LEFT SIDEBAR