PHP

PHP Data Retention

 

 

In the previous sections, you’ve been following
along and building up a HTML form. You’ve learned how to get the text from
a text box on a form, but there is a problem.

When the basicForm.php form is submitted, the details that the user
entered get erased. You’re left with the VALUE that was set in the HTML. For
us, username kept appearing in the text box when the button was clicked. You
can keep the data the user entered quite easily.

Your script should now look like the one in the link below. If not copy and
paste this script, and test it out on your server. (Save the script as basicForm.php.)

If you look at the VALUE attribute of the text box in the HTML from the above
script, you’ll see that it’s set to “username“. Because the
form gets posted back to itself, this value will keep re-appearing in the
textbox when the page is submitted. Worse, if you’ve left the Value attributes
empty then everything the user entered will disappear. This can be very annoying,
if you’re asking the user to try again. Better is to POST back the values
that the user entered.

To post the details back to the form, and thus keep the data the user has
already typed out, you can use this:

VALUE=”<?PHP print $username ; ?>”

In other words, the VALUE attribute is now a PHP line of code. The line of
code is just this:

<?PHP

print $username ;

?>

It’s a bit hard to read, because it’s all on one line.

You also need to amend your PHP code in the HEAD section to include an else
statement:

if (isset($_POST[‘Submit1’])) {

$username = $_POST[‘username’];

if ($username == “letmein”) {

print (“Welcome back, friend!”);

}
else {

print (“You’re not a member of this site”);

}

}
else {

$username =””;

}

In the else statement at the end, we’re just setting the value of the variable
called $username for when the button is NOT clicked, i.e. when the page is
refreshed.

However, there are some security issues associated with textboxes (and other
form elements). So we’ll see a more secure way to handle these in a later
section.

But our new line of HTML for our textbox reads like this:

<INPUT TYPE = ‘TEXT’ Name =’username’ VALUE=”<?PHP
print $username ; ?>
“>

In other words, we’re now printing out the VALUE attribute with PHP code.

 

Now that you know a few things about getting values from HTML forms, here’s
a few exercise

Exercise
Add two text boxes and a Submit button to a HTML form. Invite the user to
enter a first name and surname. When the button is clicked, print out the
person’s full name. Don’t worry about what is in the text boxes after the
button is clicked.

Exercise
Using the same form as the previous exercise, display the first name and surname
in the textboxes, instead of printing them out.

 

In the next section, we’ll take a look at how to handle Radion Buttons on
a HTML Form.

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Kaynak : https://www.homeandlearn.co.uk/php/php4p9.html ‘sitesinden alıntı

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