PHP : Upload Class - Simple and Flexible Script

This is a very userful php upload script in the form of flexible, simple and powerful PHP upload class. This class is meant to validate and manage files uploaded via Web forms.

It is the ideal class to quickly integrate file upload and manipulation in your site. This script will allow you to upload files from your browser to your hosting, using PHP.

Features

    Uploads any image / file
    File name extension validation to accept only files with a given list of extensions
    Check whether the files exceeds the given size limit
    Safely renames the file – removes spaces, special characters etc
    Options to overwrite or make unique
    File extension validation
    Flexible error reporting system
    Check if a directory and/or file exist
    Chip PHP upload class allows you to select and upload multiple files at once rather than having to select and upload each file individually.

Requirements

    PHP5 or higher

Learning and handling of PHP upload class by TutorialChip is very easy and flexible. I have also given a complete demo and usage in the download archive for your understanding, and i am going to explain the installation of this class step by step online as well.
Client Side Tutorial: File Upload HTML Form

It is the very important step to prepare the form for uploading files.

    First important thing is to set "enctype" attribute in the form tag. i.e enctype="multipart/form-data"
    PHP Upload Class is very powerful as it can handle "Single/Multiple" uploads easily, So you have to define the file input as an array i.e upload_file[]. You can view in the given code snippet.

File Upload Form: Single File Example

   
<form method="post" action="" enctype="multipart/form-data">
<p>Upload File: <input name="upload_file[]" id="upload_file[]" type="file" class="inputtext" /></p>
<input type="submit" name="submit" value="Upload File" />
</form>
File Upload Form: Multiple File Example

   
<form method="post" action="" enctype="multipart/form-data">
<p>Upload File 1: <input name="upload_file[]" id="upload_file[]" type="file" class="inputtext" /></p>
<p>Upload File 2: <input name="upload_file[]" id="upload_file[]" type="file" class="inputtext" /></p>
<p>Upload File 3: <input name="upload_file[]" id="upload_file[]" type="file" class="inputtext" /></p>
<p>Upload File 4: <input name="upload_file[]" id="upload_file[]" type="file" class="inputtext" /></p>
<p>Upload File 5: <input name="upload_file[]" id="upload_file[]" type="file" class="inputtext" /></p>
<input type="submit" name="submit" value="Upload File" />
</form>
Server Side Tutorial

As we have already prepared our form to send data to the PHP server to upload files. Now it is time to learn PHP upload class handling to complete this process smoothly.Auto Detection of Script Directory

PHP Upload Class script will try to detect the her directory path automatically by built-in Magic Constant of PHP i.e __DIR__. However you can alter it according to your need.

   
/*
|-----------------
| Chip Constant Manipulation
|------------------
*/

define( "CHIP_DEMO_FSROOT",     __DIR__ . "/" );
Include "class.chip_upload.php"

You have to include PHP upload file in your file at the suitable position you think. I will recommend to include this class in your POST block. Don’t worry about POST block, you can easily understand it as the tutorial moves and from a descriptive demo in the download archive.

   
/*
|-----------------
| Chip Upload Class
|------------------
*/

require_once("class.chip_upload.php");
Upload Directory Path

Next step is to define upload directory path. This is the directory where you want to save your uploaded files. I have defined it "uploads", which is a directory in the download archive. Make sure that this directory should be writable.

   
/*
|-----------------
| Upload(s) Directory
|------------------
*/

$upload_directory = CHIP_DEMO_FSROOT . "uploads/";
Class Instance

It is time to make instance of PHP upload class now.
   
/*
|-----------------
| Class Instance
|------------------
*/

$object = new chip_upload();
$_FILES Manipulation

Our form will send files in the "upload_file" array which is packed in $_FILES. Our class is very powerful to handle Single and Multiple files efficiently, so we will pass this array to the "get_upload_var" method which will arrange this array for next processing professionally.
   
/*
|-----------------
| $_FILES Manipulation
|------------------
*/

$files = $object->get_upload_var( $_FILES['upload_file'] );
Powerful Upload Loop

Now we will start loop to upload files one by one. Let’s dissect this loop part by part. We are going to provide "$files" array to this loop.

   
/*
|-----------------
| Upload File
|------------------
*/

foreach( $files as $file ) {
Powerful Upload Loop

It is time to prepare inputs for class operation. Chip Upload class will take two parameters,
Array: $args

    upload_file (Array): It will hold uploaded file array. You have to simply pass $file to this array as we are dissecting foreach loop on $file variable.
    upload_directory (String – Correct Absolute Path): You have to provide a correct absolute path to this variable. We have already calculated this variable as $upload_directory
    allowed_size (Integer – In Bytes): You have to provide maximum upload size to this part. You have to given size in bytes. 1Kb = 1024 bytes
    extension_check (Boolean – TRUE | FALSE): This part will allow you to control over specific files to upload.
    upload_overwrite (Boolean – TRUE | FALSE): This part will allow you to control for over-writing existing file or not. If set False, PHP upload class will automatically determine new name that will be based on your assigned name or uploaded file name.

Array: $allowed_extensions

If you have set "extension_check" TRUE, in the $args array, than you can modify default list to allow or disallow in the following format.

   
/*
|---------------------------
| Upload Inputs
|---------------------------
*/

$args = array(
  'upload_file'     =>   $file,
  'upload_directory'    =>   $upload_directory,
  'allowed_size'        =>   512000,
  'extension_check' =>   TRUE,
  'upload_overwrite'    =>   FALSE,
 );

$allowed_extensions = array(
  'pdf' => FALSE,
);
Upload Hook

Upload Hook is very powerful feature of Chip PHP upload class. This hook will provide you a detail analysis of uploaded data after processing but before moving file to the directory, So you have a flexibility to do anything before processing the file to the upload directory. A sample code and output of this hook will be like,

   
/*
|---------------------------
| Upload Hook
|---------------------------
*/

$upload_hook = $object->get_upload( $args, $allowed_extensions );

Array
(
    [upload_directory] => Valid - E:\wamp\www\tutorialchip\chip_upload/uploads/
    [upload_directory_writable] => Valid - Directory is writable
    [upload_file_extension] => Valid - Extension is allowed
    [upload_file_size] => Valid - Size 97854 bytes
    [upload_process] => 4
    [upload_move] => 1
    [upload_overwrite] =>
    [upload_file] => Array
        (
            [name] => nature.jpg
            [type] => image/jpeg
            [tmp_name] => E:\wamp\tmp\phpAA65.tmp
            <div class="error"><div class="box-content">Content</div><div class="clear"></div></div> => 0
            [error_status] => All OK
            [size] => 97854
            [directory] => E:\wamp\www\passive\tutorialchip\library\chip_upload/uploads/
            [nameonly] => nature
            [extension] => jpg
        )
)
Move File

You have take your time and decision by using the power of "$upload_hook" with class built-in method "get_upload". You can track any error by getting print of $upload_hook. Now it is time to move the file to the destination directory.

   
/*
|---------------------------
| Move File
|---------------------------
*/

if( $upload_hook['upload_move'] == TRUE ) {

/*
|---------------------------
| Any Logic by User
|---------------------------
*/

/*
|---------------------------
| Move File
|---------------------------
*/

$upload_output[] = $object->get_upload_move();

} else {

/*
|---------------------------
| Any Logic by User
|---------------------------
*/

}
Complete Tutorial – PHP File Upload Class / Script Example

   
/*
|-----------------
| Chip Constant Manipulation
|------------------
*/

define( "CHIP_DEMO_FSROOT",     __DIR__ . "/" );

/*
|-----------------
| POST
|------------------
*/

if( $_POST ) {

    /*
    |-----------------
    | Chip Upload Class
    |------------------
    */

    require_once("class.chip_upload.php");

    /*
    |-----------------
    | Upload(s) Directory
    |------------------
    */

    $upload_directory = CHIP_DEMO_FSROOT . "uploads/";

    /*
    |-----------------
    | Class Instance
    |------------------
    */

    $object = new chip_upload();

    /*
    |-----------------
    | $_FILES Manipulation
    |------------------
    */

    $files = $object->get_upload_var( $_FILES['upload_file'] );

    /*
    |-----------------
    | Upload File
    |------------------
    */

    foreach( $files as $file ) {

        /*
        |---------------------------
        | Upload Inputs
        |---------------------------
        */

        $args = array(
              'upload_file'         =>   $file,
              'upload_directory'    =>   $upload_directory,
              'allowed_size'        =>   512000,
              'extension_check'     =>   TRUE,
              'upload_overwrite'    =>   FALSE,
          );

        $allowed_extensions = array(
            'pdf'   => FALSE,
        );

        /*
        |---------------------------
        | Upload Hook
        |---------------------------
        */

        $upload_hook = $object->get_upload( $args, $allowed_extensions );

        /*
        |---------------------------
        | Move File
        |---------------------------
        */

        if( $upload_hook['upload_move'] == TRUE ) {

            /*
            |---------------------------
            | Any Logic by User
            |---------------------------
            */

            /*
            |---------------------------
            | Move File
            |---------------------------
            */

            $upload_output[] = $object->get_upload_move();
            //$object->chip_print( $upload_output );

        } else {

            /*$temp['uploaded_status'] = FALSE;
            $temp['uploaded_file'] = $upload_hook['upload_file']['name'] ;

            $upload_output[] = $temp;*/

        }

    } // foreach( $files as $file )

} // if( $_POST )

PHP with OOPS

We can imagine our universe made of different objects like sun, earth, moon etc. Similarly we can imagine our car made of different objects like wheel, steering, gear etc. Same way there is object oriented programming concepts which assume everything as an object and implement a software using different objects.

Object Oriented Concepts:

Before we go in detail, lets define important terms related to Object Oriented Programming.

• Class: This is a programmer-defined datatype, which includes local functions as well as local data. You can think of a class as a template for making many instances of the same kind (or class) of object.
• Object: An individual instance of the data structure defined by a class. You define a class once and then make many objects that belong to it. Objects are also known as instance.
• Member Variable: These are the variables defined inside a class. This data will be invisible to the outside of the class and can be accessed via member functions. These variables are called attribute of the object once an object is created.
• Member function: These are the function defined inside a class and are used to access object data.
• Inheritance: When a class is defined by inheriting existing function of a parent class then it is called inheritance. Here child class will inherit all or few member functions and variables of a parent class.
• Parent class: A class that is inherited from by another class. This is also called a base class or super class.
• Child Class: A class that inherits from another class. This is also called a subclass or derived class.
• Polymorphism: This is an object oriented concept where same function can be used for different purposes. For example function name will remain same but it make take different number of arguments and can do different task.
• Overloading: a type of polymorphism in which some or all of operators have different implementations depending on the types of their arguments. Similarly functions can also be overloaded with different implementation.
• Data Abstraction: Any representation of data in which the implementation details are hidden (abstracted).
• Encapsulation: refers to a concept where we encapsulate all the data and member functions together to form an object.
• Constructor: refers to a special type of function which will be called automatically whenever there is an object formation from a class.
• Destructors: refers to a special type of function which will be called automatically whenever an object is deleted or goes out of scope.

Defining PHP Classes:

The general form for defining a new class in PHP is as follows:

<?php class phpClass{ var $var1; var $var2 = "constant string"; function myfunc ($arg1, $arg2) { [..] } [..] } ?>

Here is the description of each line:

• The special form class, followed by the name of the class that you want to define.
• A set of braces enclosing any number of variable declarations and function definitions.
• Variable declarations start with the special form var, which is followed by a conventional $ variable name; they may also have an initial assignment to a constant value.
• Function definitions look much like standalone PHP functions but are local to the class and will be used to set and access object data.

Example:

Here is an example which defines a class of Books type:

<?php class Books{ /* Member variables */ var $price; var $title; /* Member functions */ function setPrice($par){ $this->price = $par; } function getPrice(){ echo $this->price ."<br/>"; } function setTitle($par){ $this->title = $par; } function getTitle(){ echo $this->title ." <br/>"; } } ?>

The variable $this is a special variable and it refers to the same object ie. itself.

Creating Objects in PHP

Once you defined your class, then you can create as many objects as you like of that class type. Following is an example of how to create object using new operator.

$physics = new Books; $maths = new Books; $chemistry = new Books;

Here we have created three objects and these objects are independent of each other and they will have their existance separately. Next we will see how to access member function and process member variables.

Calling Member Functions

After creating your objects, you will be able to call member functions related to that object. One member function will be able to process member variable of related object only.
Following example shows how to set title and prices for the three books by calling member functions.

$physics->setTitle( "Physics for High School" ); $chemistry->setTitle( "Advanced Chemistry" ); $maths->setTitle( "Algebra" ); $physics->setPrice( 10 ); $chemistry->setPrice( 15 ); $maths->setPrice( 7 );

Now you call another member functions to get the values set by in above example:

$physics->getTitle(); $chemistry->getTitle(); $maths->getTitle(); $physics->getPrice(); $chemistry->getPrice(); $maths->getPrice();

This will produce follwoing result:

Physics for High School Advanced Chemistry Algebra 10 15 7

Constructor Functions:

Constructor Functions are special type of functions which are called automatically whenever an object is created. So we take full advantage of this behaviour, by initializing many things through constructor functions.
PHP provides a special function called __construct() to define a constructor. You can pass as many as arguments you like into the constructor function.
Following example will create one constructor for Books class and it will initialize price and title for the book at the time of object creation.

function __construct( $par1, $par2 ){ $this->price = $par1; $this->title = $par2; }

Now we don't need to call set function separately to set price and title. We can initialize these two member variables at the time of object creation only. Check following example below:

$physics = new Books( "Physics for High School", 10 ); $maths = new Books ( "Advanced Chemistry", 15 ); $chemistry = new Books ("Algebra", 7 ); /* Get those set values */ $physics->getTitle(); $chemistry->getTitle(); $maths->getTitle(); $physics->getPrice(); $chemistry->getPrice(); $maths->getPrice();

This will produce following result:

Physics for High School Advanced Chemistry Algebra 10 15 7

Destructor:

Like a constructor function you can define a destructor function using function __destruct(). You can release all the resourceses with-in a destructor.

Inheritance:

PHP class definitions can optionally inherit from a parent class definition by using the extends clause. The syntax is as follows:

class Child extends Parent { <definition body> }

The effect of inheritance is that the child class (or subclass or derived class) has the following characteristics:

• Automatically has all the member variable declarations of the parent class.
• Automatically has all the same member functions as the parent, which (by default) will work the same way as those functions do in the parent.

Following example inherit Books class and adds more functionality based on the requirement.

class Novel extends Books{ var publisher; function setPublisher($par){ $this->publisher = $par; } function getPublisher(){ echo $this->publisher. "<br />"; } }

Now apart from inherited functions, class Novel keeps two additional member functions.

Function Overriding:

Function definitions in child classes override definitions with the same name in parent classes. In a child class, we can modify the definition of a function inherited from parent class.
In the follwoing example getPrice and getTitle functions are overriden to retrun some values.

function getPrice(){ echo $this->price . "<br/>"; return $this->price; } function getTitle(){ echo $this->title . "<br/>"; return $this->title; }

Public Members:

Unless you specify otherwise, properties and methods of a class are public. That is to say, they may be accessed in three possible situations:

• From outside the class in which it is declared
• From within the class in which it is declared
• From within another class that implements the class in which it is declared

Till now we have seen all members as public members. If you wish to limit the accessibility of the members of a class then you define class members as private or protected.

Private members:

By designating a member private, you limit its accessibility to the class in which it is declared. The private member cannot be referred to from classes that inherit the class in which it is declared and cannot be accessed from outside the class.
A class member can be made private by using private keyword infront of the member.

class MyClass { private $car = "skoda"; $driver = "SRK"; function __construct($par) { // Statements here run every time // an instance of the class // is created. } function myPublicFunction() { return("I'm visible!"); } private function myPrivateFunction() { return("I'm not visible outside!"); } }

When MyClass class is inherited by another class using extends, myPublicFunction() will be visible, as will $driver. The extending class will not have any awareness of or access to myPrivateFunction and $car, because they are declared private.

Protected members:

A protected property or method is accessible in the class in which it is declared, as well as in classes that extend that class. Protected members are not available outside of those two kinds of classes. A class member can be made protected by using protected keyword infront of the member.
Here is different version of MyClass:

class MyClass { protected $car = "skoda"; $driver = "SRK"; function __construct($par) { // Statements here run every time // an instance of the class // is created. } function myPublicFunction() { return("I'm visible!"); } protected function myPrivateFunction() { return("I'm visible in child class!"); } }

Interfaces:

Interfaces are defined to provide a common function names to the implementors. Different implementors can implement those interfaces according to theri requirements. You can say, interfaces are skeltons which are implemented by developers.
As of PHP5, it is possible to define an interface, like this:

interface Mail { public function sendMail(); }

Then, if another class implemented that interface, like this:

class Report implements Mail { // sendMail() Definition goes here }

Constants:

A constant is somewhat like a variable, in that it holds a value, but is really more like a function because a constant is immutable. Once you declare a constant, it does not change.
Declaring one constant is easy, as is done in this version of MyClass:

class MyClass { const requiredMargin = 1.7; function __construct($incomingValue) { // Statements here run every time // an instance of the class // is created. } }

In this class, requiredMargin is a constant. It is declared with the keyword const, and under no circumstances can it be changed to anything other than 1.7. Note that the constant's name does not have a leading $, as variable names do.

Abstract Classes:

An abstract class is one that cannot be instantiated, only inherited. You declare an abstract class with the keyword abstract, like this:
When inheriting from an abstract class, all methods marked abstract in the parent's class declaration must be defined by the child; additionally, these methods must be defined with the same visibillity.

abstract class MyAbstractClass { abstract function myAbstractFunction() { } }

Note that function definitions inside an abstract class must also be preceded by the keyword abstract. It is not legal to have abstract function definitions inside a non-abstract class.

Static Keyword:

Declaring class members or methods as static makes them accessible without needing an instantiation of the class. A member declared as static can not be accessed with an instantiated class object (though a static method can).
Try out following example:

<?php class Foo { public static $my_static = 'foo'; public function staticValue() { return self::$my_static; } } print Foo::$my_static . "\n"; $foo = new Foo(); print $foo->staticValue() . "\n";

Final Keyword:

PHP 5 introduces the final keyword, which prevents child classes from overriding a method by prefixing the definition with final. If the class itself is being defined final then it cannot be extended.
Following example results in Fatal error: Cannot override final method BaseClass::moreTesting()

<?php class BaseClass { public function test() { echo "BaseClass::test() called<br>"; } final public function moreTesting() { echo "BaseClass::moreTesting() called<br>"; } } class ChildClass extends BaseClass { public function moreTesting() { echo "ChildClass::moreTesting() called<br>"; } } ?>

Calling parent constructors:

Instead of writing an entirely new constructor for the subclass, let's write it by calling the parent's constructor explicitly and then doing whatever is necessary in addition for instantiation of the subclass. Here's a simple example:

class Name { var $_firstName; var $_lastName; function Name($first_name, $last_name) { $this->_firstName = $first_name; $this->_lastName = $last_name; } function toString() { return($this->_lastName .", " .$this->_firstName); } } class NameSub1 extends Name { var $_middleInitial; function NameSub1($first_name, $middle_initial, $last_name) { Name::Name($first_name, $last_name); $this->_middleInitial = $middle_initial; } function toString() { return(Name::toString() . " " . $this->_middleInitial); } }

In this example, we have a parent class (Name), which has a two-argument constructor, and a subclass (NameSub1), which has a three-argument constructor. The constructor of NameSub1 functions by calling its parent constructor explicitly using the :: syntax (passing two of its arguments along) and then setting an additional field. Similarly, NameSub1 defines its nonconstructor toString() function in terms of the parent function that it overrides.
NOTE: A constructor can be defined with the same name as the name of a class. It is defined in above example.