introduction to php web programming - get and post
TRANSCRIPT
Introduction to PHPWeb programming
Week 11, day2
Web programming
PHP with HTML
• You can embed PHP code inside html:<html>
<body>
<h1>
<?php
$str_one = "Helloo World!";
echo $str_one;
?>
</h1>
</body>
</html>
• Or you can call html from php:<?php
echo "<html><body><h2>Helloo Baabtra</h2></body></html>”;
?>
Client - Server communication with Form Data
When you submit the form- all form element data(username and password ) will
be send to the file ‚registration.php‛ which is residing on your server
HTML Form Example
HTML Form Example
Action specifies where to send the form data? Normally we specify a page which resides on server so that all form data will be
sent to that page. In this example when you click submit button data you entered will be send to “registation.php”
HTML Form Example
We can send data to server in two ways GET or POST.
Form action and methods
•There are two methods that we can send form data from client to server
• GET
• Allows you to send data as part of the query string.That means data will
be appended with the url
•http://example.org/index.php?list=user&orderby=name&direction=asc
• POST
Allows the client to send along a data payload, for example, if you are
posting an HTTP form, the payload could consist of the form data, while if
you are uploading a file, the payload would consist of the file itself. Payload
will be with HTTP request so that it will not be visible to the user
Comparison
• Data sent will be shown in the URL
• Size of Data can be send is limiter
normally ~2kb but its browser
dependant
• Cannot be used to send binary
data like image or document
• Bookmarking is possible with GET
method
• Data will not be shown with the browser
• No restrictions on size of data
• Can be used to send files
• Book marking is not possible with POST
method
GET POST
How will you get that data in ‚registration.php‛ ???
• All the form data sent via Get method will be stored in a super global Array
$_GET
• Eg: http://example.org/index.php?list=user&orderby=name&direction=asc
echo $_GET*’list’+;
• You can create arrays by using array notation...
Eg: http://example.org/index.php?list=user&order[by]=column&order[dir]=asc
•and then access them using the following syntax:
echo $_GET*’order’+*’by’+;
echo $_GET*’order’+*’direction’+;
How will you get that data in ‚registration.php‛ ???
• Similarly all the form data sent via POST method will be stored in a super global
array $_POST
•Eg:
echo $_POST*‘name’+; // will output baabtra
echo $_POST*‘email’+; // will output [email protected]
When You Don’t Know How Data Is Sent
• If you want to receive data send by client browser but you don’t know the method
they used to send (GET or POST), you can do this by using $_REQUEST[] super
global array
• ie. $_REQUEST[] will contain what ever data you send in any method either GET
or POST.
• Eg: echo $_REQUEST*‘name’+;
Try this• Create a HTML form as below . Try both Get and POST methods
• Up on clicking submit button it should display what user have
entered
localhost/test/Registration.php
localhost/test/Registration.php
Managing File uploads
File Uploading
• File uploads are an important feature for many Web applications;
• A file can be uploaded through a ‚multi-part‛ HTTP POST
transaction.
<form enctype="multipart/form-data" action="index.php‚ method="post">
<input type="hidden" name="MAX_FILE_SIZE" value="50000" />
<input type="file" name="filedata" />
<input type="submit" value="Send file" />
</form>
File Uploading
• File uploads are an important feature for many Web applications;
• A file can be uploaded through a ‚multi-part‛ HTTP POST
transaction.
<form enctype="multipart/form-data" action="index.php‚ method="post">
<input type="hidden" name="MAX_FILE_SIZE" value="50000" />
<input type="file" name="filedata" />
<input type="submit" value="Send file" />
</form>
is an encoding type that allows files to be sent through a POST. Quite simply, without this
encoding the files cannot be sent through POST.
File Uploading
• File uploads are an important feature for many Web applications;
• A file can be uploaded through a ‚multi-part‛ HTTP POST
transaction.
<form enctype="multipart/form-data" action="index.php‚ method="post">
<input type="hidden" name="MAX_FILE_SIZE" value="50000" />
<input type="file" name="filedata" />
<input type="submit" value="Send file" />
</form>
MAX_FILE_SIZE value is used to define the maximum file size allowed(in this case, 50,000 bytes)
File Uploading
• File uploads are an important feature for many Web applications;
• A file can be uploaded through a ‚multi-part‛ HTTP POST
transaction.
<form enctype="multipart/form-data" action="index.php‚ method="post">
<input type="hidden" name="MAX_FILE_SIZE" value="50000" />
<input type="file" name="filedata" />
<input type="submit" value="Send file" />
</form>
Tip :You can limit the amount of data uploaded by a POST operation
by modifying number of configuration directives in php.ini, such as
post_max_size, max_input_time and upload_max_filesize.
How will you receive the file at server side?
• Once a file is uploaded to the server, PHP stores it in a temporary location and
makes it available to the script; It is up to the script to move the file to a safe
location. The temporary copy is automatically destroyed when the script ends.
• Inside your script, uploaded files will appear in the $_FILES super global multi
dimensional array. This array will have the following keys
– name : The original name of the file
– type : The MIME type of the file provided by the browser
– size : The size (in bytes) of the file
– tmp_name : The name of the file’s temporary location
– error : The error code associated with this file. A value of
UPLOAD_ERR_OK indicates a successful transfer
Built in functions for file upload()
• is_uploaded_file(filename) : returns true if the file has uploaded to the
temporary location in server
• Accepts and argument ‚filename‛ which refers to the name of the file in servers
temporary position.ie it will be $_FILE*‘filename’+*‘tmp_name’+
• move_uploaded_file(source,destination) : to move an uploaded file to a
different location
• Source refers to its current location which obviously is in the temporary
location in the server ie $_FILE*‘filename’+*‘tmp_name’+
• Destination refers to where to move the file along with its name eg.
‚images/profilePics/‛. $_FILE*‘filename’+*‘name’+
form enctype="multipart/form-data" action=‚register.php‚ method="post">
<input type="file" name="filedata" />
<input type="submit" value="Send file" />
</form>
Example – File Upload
Index.html
<?php
echo $_FILE*‘filedata’+*‘name’+; // prints the name of file uploaded
echo $_FILE*‘filedata’+*‘size’+; // prints the size of file uploaded
is_uploaded_file($_FILE*‘filedata’+*‘tmp_name’+)
{
$target=‚images/‛.$_FILE*‘filedata’+*‘name’+;
move_upload_file($_FILE*‘filedata’+*‘tmp_name’+,$target);
}
?>
Example – File Upload
Register.php
Questions?
‚A good question deserve a good grade…‛
End of day
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