Refresh page without losing the Post value - php

How do I maintain the $post value when a page is refreshed; In other words how do I refresh the page without losing the Post value

This in not possible without a page submit in the first place! Unless you somehow submitted the form fields back to the server i.e. Without Page Refresh using jQuery etc. Somesort of Auto Save Form script.
If this is for validation checks no need for sessions as suggested.
User fills in the form and submits back to self
Sever side validation fails
$_GET
<input type="hidden" name="first"
value="<?php echo htmlspecialchars($first, ENT_QUOTES); ?>" />
validation message, end.
alternatively as suggested save the whole post in a session, something like this, but again has to be first submitted to work....
$_POST
if(isset($_POST) & count($_POST)) { $_SESSION['post'] = $_POST; }
if(isset($_SESSION['post']) && count($_SESSION['post'])) { $_POST = $_SESSION['post']; }

You can't do this. POST variables may not be re-sent, if they are, the browser usually does this when the user refreshes the page.
The POST variable will never be re-set if the user clicks a link to another page instead of refreshing.
If $post is a normal variable, then it will never be saved.
If you need to save something, you need to use cookies. $_SESSION is an implementation of cookies. Cookies are data that is stored on the user's browser, and are re-sent with every request.
Reference: http://php.net/manual/en/reserved.variables.session.php
The $_SESSION variable is just an associative array, so to use it, simply do something like:
$_SESSION['foo'] = $bar

You could save your $_POST values inside of $_SESSION's
Save your all $_POST's like this:
<?php
session_start();
$_SESSION['value1'] = $_POST['value1'];
$_SESSION['value2'] = $_POST['value2'];
// ETC...
echo "<input type='text' name='value1' value='".$_SESSION['value1']."' />";
echo "<input type='text' name='value2' value='".$_SESSION['value2']."' />";
?>

Actually in html forms it keeps post data.
this is valuble when you need to keep inserted data in the textboxes.
<form>
<input type="text" name="student_name" value="<?php echo
isset($_POST['student_name']) ? $_POST['student_name']:'';
?>">
</form>

put post values to session
session_start();
$_SESSION["POST_VARS"]=$_POST;
and you can fetch this value in another page like
session_start();
$_SESSION["POST_VARS"]["name"];
$_SESSION["POST_VARS"]["address"];

You can use the same value that you got in the POST inside the form, this way, when you submit it - it'll stay there.
An little example:
<?php
$var = mysql_real_escape_string($_POST['var']);
?>
<form id="1" name="1" action="/" method="post">
<input type="text" value="<?php print $var;?>"/>
<input type="submit" value="Submit" />
</form>

You can use file to save post data so the data will not will not be removed until someone remove the file and of-course you can modify the file easily
if($_POST['name'])
{
$file = fopen('poststored.txt','wb');
fwrite($file,''.$_POST['value'].'');
fclose($file);
}
if (file_exists('poststored.txt')) {
$file = fopen('ipSelected.txt', 'r');
$value = fgets($file);
fclose($file);
}
so your post value stored in $value.

Related

Store _POST into variable to use with Page Data [duplicate]

I'm making a php script that stores 3 arrays: $images, $urls, $titles based on the input data of the form within the php file.
I want to print the values of these arrays in the first part of the page and then to pre-fill the form's input fields with the value of the arrays. Also when a user modifies an input field and clicks on "Save" the page should reload with the modfied version.
My problem is that on each call of the php file in a browser the value of the variables gets deleted. Is there a way to store the values of the array so that the form always gets pre-filled with the last saved values?
<?php
//save the arrays with the form data
$images = array($_POST["i0"],$_POST["i1"],$_POST["i2"],$_POST["i3"]);
$urls = array($_POST["u0"],$_POST["u1"],$_POST["u2"],$_POST["u3"]);
$titles = array($_POST["t0"],$_POST["t1"],$_POST["t2"],$_POST["t3"]);
//print the arrays
print_r($images);
print_r($urls);
print_r($titles);
//create the form and populate it
echo "<p><form method='post' action='".$_SERVER['PHP_SELF']."';";
$x = 0;
while ($x <= 3) {
echo"<div>
<input name='i".$x."' type='text' value='".$images[$x]."'>
<input name='u".$x."' type='text' value='".$urls[$x]."'>
<input name='t".$x."' type='text' value='".$titles[$x]."'>";
$x++;
}
?>
<br>
<input type="submit" name="sumbit" value="Save"><br>
</form>
Store the variables in a PHP session.
session_start();
$_SESSION['images'] = $images;
Then on next (or any other) page, you can retrieve the values as:
session_start();
$images = $_SESSION['images'];
Changing the scope of the variables to a larger scope, might do the trick. Also, check if you have a post request before updating the values.
<?php
if(sizeof($_POST) >0)
{
//UPDATE VALUES
}
?>
If you want a permanent storage of state, between different pages, you should use sessions, by putting session_start(); in the start of your script. After this, every variable $_SESSION[$x] will be persisted, and will be available to your scripts.
However, in this particular case, answering your question: "Is there a way to store the values of the array so that the form always gets pre-filled with the last saved values?", it is easier to just use the $_POST variable if it exists already:
<?php
if(!$_POST){
$_POST = array();
foreach(array("i0","i1","i2","i3") as $i) $_POST[$i]="";
foreach(array("u0","u1","u2","u3") as $i) $_POST[$i]="";
foreach(array("t0","t1","t2","t3") as $i) $_POST[$i]="";
}
foreach($_POST as $k=>$v) filter_input(INPUT_POST,$k,FILTER_SANITIZE_SPECIAL_CHARS);
//save the arrays with the form data
$images = array($_POST["i0"], $_POST["i1"], $_POST["i2"], $_POST["i3"]);
$urls = array($_POST["u0"], $_POST["u1"], $_POST["u2"], $_POST["u3"]);
$titles = array($_POST["t0"], $_POST["t1"], $_POST["t2"], $_POST["t3"]);
//print the arrays
print_r($images);
print_r($urls);
print_r($titles);
//create the form and populate it
echo "<p><form method='post' action='".$_SERVER['PHP_SELF']."';";
$x = 0;
while ($x <= 3) {
echo"<div>
<input name='i".$x."' type='text' value='".$images[$x]."'>
<input name='u".$x."' type='text' value='".$urls[$x]."'>
<input name='t".$x."' type='text' value='".$titles[$x]."'>";
$x++;
}
?>
<br>
<input type="submit" name="sumbit" value="Save"><br>
</form>
Note: this line foreach($_POST as $k=>$v) filter_input(INPUT_POST,$k,FILTER_SANITIZE_SPECIAL_CHARS);
should be enough to protect you from basic XSS attacks.
Note also that in general, it is best to follow the pattern of reloading pages with GET after POST, which makes you less susceptible to form resubmitions, in which case using sessions for storage is the better solution.
What brought me here was somewhat different kind of beast. I had problem with subsequent post request from AXIS IP camera and needed to preserve last file name across requests. In case that someone stumble here looking for some way to cache variables and SESSION is not an option maybe should look at Alternative PHP Cache:
Note: Unlike many other mechanisms in PHP, variables stored using
apc_store() will persist between requests (until the value is removed
from the cache).
http://php.net/manual/en/book.apc.php
Use sessions: http://php.net/manual/en/function.session-start.php
You can use sessions to store values and write rules to refill form fields after validations on data submit. Also function isset() is very helpful to avoid "not defined" errors.
The solution you are looking for is the session. Use $_SESSION to store value of Your variables. For example, at the end of script:
$_SESSION['images'] = $images;
and in form's input:
<input name='i".$x."' type='text' value='".(isset($_SESSION['images']) ?
$_SESSION['images'] : '')."'>

Possible to manipulate $_POST variable in php script and express it in another php script?

I've been trying to do form validation without using the url. So I thought that I would create a hidden field in my form and send it over to my validation php script. What I was hoping I would be able to do is set what ever errors there are in the form to this hidden field and return it. However once I get out of the scope it destroys whatever I set. I thought $_POST had global scope? Maybe I declared I set the hidden field wrong? I have placed the code below.
<?php
include_once $_SERVER['DOCUMENT_ROOT'].'/poles/config/databaseConnect.php';
include_once $_SERVER['DOCUMENT_ROOT'].'/poles/config/functions.php';
include_once $_SERVER['DOCUMENT_ROOT'].'/poles/models/users.php';
include_once $_SERVER['DOCUMENT_ROOT'].'/poles/models/userDetails.php';
//get the refering url to be used to redirect
$refUrl = $_SERVER['HTTP_REFERER'];
if(isset($_POST['register'])){
//declare a temp error array
$tempError;
//check if the form is empty
if(empty($_POST['Email'])&&empty($_POST['Email Confirmation'])&&empty($_POST['Password'])&&empty($_POST['Password Confirmation'])
&&empty($_POST['Stage Name'])&&empty($_POST['Main Club'])){
$tempError = 'Please fill in the form.';
}else{
//set variables
}
if(!empty($tempError)){
//start a session to declare session errors
$_POST['errors'] = $tempError;
//redirect back to referring url
header('Location:'.$refUrl);
exit();
}else{
//log user in and redirect to member home page
}
}
Basic form (I excluded the input field as it would be really long)
<div class="col-md-6 well">
<span class="jsError"></span><?php if(isset($_POST['errors'])){ $errors = $_POST['errors']; } if(!empty($errors)){ echo '<p class="alert alert-danger text-center">'.$errors.'</p>'; } ?>
<form class="form-horizontal" role="form" method="post" action="controllers/registrationController.php" id="registration">
<input type="hidden" name="errors" value="<?php if(isset($_POST['errors'])){echo $_POST['errors']; } ?>">
</form>
I looked into using the $_SESSION variable method too but the stuff I found was either a bit complicated or it involved me starting a whole bunch of sessions everywhere (would make my code messy in my opinion).
$_POST is populated from the contents of the data passed by the browser to the server. When you send a Location header it causes the browser to load a new page, but since it will have no form data, nothing will be passed.
If you need to pass data from page to page then $_SESSION is the way to go. All that is required is a session_start() at the top of the pages that need access, and you can store your $_POST data like this:
$_SESSION['postdata'] = $_POST;
Retrieving it becomes
$email = $_SESSION['post']['Email'];
The alternative is to echo the data as a hidden <input> in a new form, but that will require a new form to be submitted and I get the feeling you want something seamless.
Note also that $_SERVER['HTTP_REFERER'] is not guaranteed to be accurate, or even present. You shouldn't rely on this for production code. It might work for you with your browser in your test set-up, but that's no guarantee it'll work for other browsers. Find another way.
You can achieve this by using javascript instead of a redirect, but the only way to pass data through a redirect is via the URL, the session, or cookies.
$_POST['errors'] = $tempError;
//redirect back to referring url
?>
<html><head><title></title></head><body>
<form id="temp_form">
<?php
foreach($_POST as $k=>$v) {
?><input type="hidden" name="<?php echo htmlentities($k); ?>" value="<?php echo htmlentities($v); ?>" /><?php
}
?>
</form>
<script type="text/javascript">
setTimeout(function() { document.getElementById('temp_form').submit(); },100);
</script>
</body>
</html>
<?php
die();

how to store variable values over multiple page loads

I'm making a php script that stores 3 arrays: $images, $urls, $titles based on the input data of the form within the php file.
I want to print the values of these arrays in the first part of the page and then to pre-fill the form's input fields with the value of the arrays. Also when a user modifies an input field and clicks on "Save" the page should reload with the modfied version.
My problem is that on each call of the php file in a browser the value of the variables gets deleted. Is there a way to store the values of the array so that the form always gets pre-filled with the last saved values?
<?php
//save the arrays with the form data
$images = array($_POST["i0"],$_POST["i1"],$_POST["i2"],$_POST["i3"]);
$urls = array($_POST["u0"],$_POST["u1"],$_POST["u2"],$_POST["u3"]);
$titles = array($_POST["t0"],$_POST["t1"],$_POST["t2"],$_POST["t3"]);
//print the arrays
print_r($images);
print_r($urls);
print_r($titles);
//create the form and populate it
echo "<p><form method='post' action='".$_SERVER['PHP_SELF']."';";
$x = 0;
while ($x <= 3) {
echo"<div>
<input name='i".$x."' type='text' value='".$images[$x]."'>
<input name='u".$x."' type='text' value='".$urls[$x]."'>
<input name='t".$x."' type='text' value='".$titles[$x]."'>";
$x++;
}
?>
<br>
<input type="submit" name="sumbit" value="Save"><br>
</form>
Store the variables in a PHP session.
session_start();
$_SESSION['images'] = $images;
Then on next (or any other) page, you can retrieve the values as:
session_start();
$images = $_SESSION['images'];
Changing the scope of the variables to a larger scope, might do the trick. Also, check if you have a post request before updating the values.
<?php
if(sizeof($_POST) >0)
{
//UPDATE VALUES
}
?>
If you want a permanent storage of state, between different pages, you should use sessions, by putting session_start(); in the start of your script. After this, every variable $_SESSION[$x] will be persisted, and will be available to your scripts.
However, in this particular case, answering your question: "Is there a way to store the values of the array so that the form always gets pre-filled with the last saved values?", it is easier to just use the $_POST variable if it exists already:
<?php
if(!$_POST){
$_POST = array();
foreach(array("i0","i1","i2","i3") as $i) $_POST[$i]="";
foreach(array("u0","u1","u2","u3") as $i) $_POST[$i]="";
foreach(array("t0","t1","t2","t3") as $i) $_POST[$i]="";
}
foreach($_POST as $k=>$v) filter_input(INPUT_POST,$k,FILTER_SANITIZE_SPECIAL_CHARS);
//save the arrays with the form data
$images = array($_POST["i0"], $_POST["i1"], $_POST["i2"], $_POST["i3"]);
$urls = array($_POST["u0"], $_POST["u1"], $_POST["u2"], $_POST["u3"]);
$titles = array($_POST["t0"], $_POST["t1"], $_POST["t2"], $_POST["t3"]);
//print the arrays
print_r($images);
print_r($urls);
print_r($titles);
//create the form and populate it
echo "<p><form method='post' action='".$_SERVER['PHP_SELF']."';";
$x = 0;
while ($x <= 3) {
echo"<div>
<input name='i".$x."' type='text' value='".$images[$x]."'>
<input name='u".$x."' type='text' value='".$urls[$x]."'>
<input name='t".$x."' type='text' value='".$titles[$x]."'>";
$x++;
}
?>
<br>
<input type="submit" name="sumbit" value="Save"><br>
</form>
Note: this line foreach($_POST as $k=>$v) filter_input(INPUT_POST,$k,FILTER_SANITIZE_SPECIAL_CHARS);
should be enough to protect you from basic XSS attacks.
Note also that in general, it is best to follow the pattern of reloading pages with GET after POST, which makes you less susceptible to form resubmitions, in which case using sessions for storage is the better solution.
What brought me here was somewhat different kind of beast. I had problem with subsequent post request from AXIS IP camera and needed to preserve last file name across requests. In case that someone stumble here looking for some way to cache variables and SESSION is not an option maybe should look at Alternative PHP Cache:
Note: Unlike many other mechanisms in PHP, variables stored using
apc_store() will persist between requests (until the value is removed
from the cache).
http://php.net/manual/en/book.apc.php
Use sessions: http://php.net/manual/en/function.session-start.php
You can use sessions to store values and write rules to refill form fields after validations on data submit. Also function isset() is very helpful to avoid "not defined" errors.
The solution you are looking for is the session. Use $_SESSION to store value of Your variables. For example, at the end of script:
$_SESSION['images'] = $images;
and in form's input:
<input name='i".$x."' type='text' value='".(isset($_SESSION['images']) ?
$_SESSION['images'] : '')."'>

How to keep all the POST information while redirecting in PHP?

header('Location: ' . $uri);
This will miss all the $_POST information.
Don't use $_SESSION as you have been suggested. Session data is shared with all other pages, including the ones open in other tabs. You may get unpredictable behaviour if you use the same trick in multiple places of your website.
An untested better code would be something like this.
session_start();
$data_id = md5( time().microtime().rand(0,100) );
$_SESSION["POSTDATA_$data_id"] = $_POST;
header('Location: ' . $uri."?data_id=$data_id");
In the next page you may retrieve the previous post like this
session_start();
$post = array();
$data_key = 'POSTDATA_'.$_GET['data_id'];
if ( !empty ( $_GET['data_id'] ) && !empty( $_SESSION[$data_key] ))
{
$post = $_SESSION[$data_key];
unset ( $_SESSION[$data_key] );
}
The code above is not tested, you may have to deal with some error before it works.
if u want to carry forward your POST data to another pages ( except the action page) then use
session_start();
$_SESSION['post_data'] = $_POST;
Indeed, you can't redirect POST requests.
Either let your server proxy the request (i.e. make a cURL request to the other site) or create another form, fill it with hidden fields and submit it with Javascript/let the user click.
Alternatively, as #diEcho says, depending on what you're trying to do: sessions.
If you perform a redirect the post will be lost and a GET will occur.
You could save your POST in a SESSION or encode it in the GET (as query string)
You could save the post data in the session, redirect, and then retrieve it back from the session.
session_start();
$_SESSION['POSTDATA'] = $_POST;
header('Location: ' . $uri);
Then in the PHP file for the new location, retrieve the post data like this:
$_POST = $_SESSION['POSTDATA'];
I do use my own simple method.
Just think very logical! For example if you use a text attribute which you want to keep the value of, you can use:
<?php $textvalue = $_POST['textname']; ?>
<input type="text" name="textname" value="<?php echo $textvalue; ?>" />
<br />
//And if you want to use this method for a radio button, you can use:
<?php if(isset($_POST['radio1']){
$selected = "selected";
} ?>
<input type="radio" name="radio1" <?php echo $selected; ?> />

Retaining values in forms fields when validation of data fails

I am having problems figuring out how to retain users data when the validation fails. I am somewhat new to PHP so I might be making some huge mistakes in my logic.
Currently if the validation fails all the fields are wiped clean and $_Post data is also gone.
Here is some code assuming the user enters an invalid email I want the Name field to be retained. This code is not working.
<?php
if($_POST['doSubmit'] == 'Submit') {
$usr_name = $data['Name'];
$usr_email = $data['Email'];
if (isEmail($usr_email)==FALSE){
$err = "Email is invalid.");
header("Location: index.php?msg=$err");
exit();
}
//do whatever with data
}
if (isset($_GET['msg'])) {
$msg = mysql_real_escape_string($_GET['msg']);
echo "<div class=\"msg\">$msg</div><hr />";
}
if (isset ($_POST['Name'])){
$reusername = $_POST['Name'];}
else{$reusername = "NOTHING";}//to test
?>
<form action="index.php" method="post" >
<input name="UserName" type="text" size="30" value="<?echo $reusername;?>">
<input name="Email" type="text" size="30">
<input name="doSubmit" type="submit" value="submit">
</form>
}
You can use AJAX to submit your form data to your PHP script and have it return JSON data that specifies whether the validation was successful or not. That way, your fields won't be wiped clean.
Another way is to send back the recorded parameters to the posting page, and in the posting page, populate the fields using PHP.
However, I think the first solution is better.
UPDATE
The edit makes your code clearer and so I noticed something. Your input field is called UserName in the HTML, but you are referring to Name in PHP. That's probably why it's not working. Is your field always being filled with the value NOTHING? Make sure the name of the input field and the subscript you are using in $_POST are the same.
Also, there's no need to redirect to another page (using header) if you have an error. Maintain an $errors array or variable to print error messages in the same page. But like I mentioned before, it's probably better to use the JSON approach since then you can separate your view layer (the html) from the PHP (controller layer). So you'd put your HTML in one file, and your PHP in another file.
EDIT:
Vivin had commented that my assumption regarding the header was incorrect and he was right in that. Further more it looks like what the OP is doing is essentially what i layed out below albeit in a less structured fashion. Further Vivin - caught what is likely the actual problem here - the html name and the array key $_POST do not match.
Its wiped clean because you are using header to redirect to another page. Typicaly you would have a single page that validates the data and if ok does something with it and returns a success view of some sort, or that returns an error view directly showing the form again. By using header youre actually redirecting the browser to another page (ie. starting up an entirely new request).
For example:
// myform.php
if(strtolower($_SERVER['REQUEST_METHOD']) == 'get')
{
ob_start();
include('form.inc.php'); // we load the actual view - the html/php file
$content = ob_get_clean();
print $content; // we print the contents of the view to the browser
exit;
}
elseif(strtolower($_SERVER['REQUEST_METHOD']) == 'post')
{
$form = santize($_POST); // clean up the input... htmlentities, date format filters, etc..
if($data = is_valid($form))
{
process_data($data); // this would insert it in the db, or email it, etc..
}
else
{
$errors = get_errors(); // this would get our error messages associated with each form field indexed by the same key as $form
ob_start();
include('form.inc.php'); // we load the actual view - the html/php file
$content = ob_get_clean();
print $content; // we print the contents of the view to the browser
exit;
}
}
so this assumes that your form.inc.php always has the output of error messages coded into it - it just doesnt display them. So in this file you might see something like:
<fieldset>
<label for="item_1">
<?php echo isset($error['item_1']) ? $error['item_1'] : null; ?>
Item 1: <input id="item_1" value="<?php echo $form['item_1'] ?>" />
</label>
</fieldset>
Could do something similar to if failed then value=$_POST['value']
But vivin's answer is best. I don't know much about AJAX and wouldn't be able to manage that.
Ok, firstly header("Location: index.php?msg=$err"); is not really required. It's best practice not to redirect like this on error, but display errors on the same page. Also, redirecting like this means you lose all of the post data in the form so you can never print it back into the inputs.
What you need to do is this:
<input name="Email" type="text" size="30" value="<?php print (!$err && $usr_email ? htmlentities($usr_email, ENT_QUOTES) : '') ?>">
Here I'm checking whether any errors exist, then whether the $usr_email variable is set. If both these conditions are matched the post data is printed in the value attribute of the field.
The reason I'm using the function htmlentities() is because otherwise a user can inject malicious code into the page.
You appear to be processing the post on the same page as your form. This is an OK way to do things and it means you're nearly there. All you have to do is redirect if your validation is successful but not if it fails. Like this
<?php
if( isset( $_POST['number'] ) ) {
$number = $_POST['number'];
// validate
if( $number < 10 ) {
// process it and then;
header('Location: success_page.php');
} else {
$err = 'Your number is too big';
}
} else {
$number = '';
$err = '';
}
?>
<form method="POST">
Enter a number less than 10<br/>
<?php echo $err ?><br/>
<input name="number" value="<?php echo $number ?>"><br/>
<input type="submit">
</form>

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