I have an HTML form. Let's say I fill out all the fields and submit it (PHP script runs here).
Then I want to go back to the form using "Back" button of my browser.
What I see is the empty form.
What do I do to have the entered data retain on the page after I come back to it using "Back" button of the browser?
Thank you!
If you use the "Back" button of your browser then your browser is responsible for re-populating your form data.
Usually that functionality is handled by the browser, however if you want to "force" the fields to always be pre-filled with the user's data, you can store the $_POST data in a session variable and use that to load the form.
Example:
// submission page
session_start();
if(isset($_POST)){
// save the posted data in the session
$_SESSION["POST"] = $_POST;
}
Then on the actual form page, you can check to see if session data exists. It won't if the form is being loaded the first time, but it will if the user submits the form and then presses the browser back button:
// form page
session_start();
if(isset($_SESSION["POST"])){
// previous POST data has been saved
// build the form with pre-defined values from $_SESSION
...
} else {
// no previous data
// build the form without pre-defined values
...
}
Note that you must call session_start() before outputting any HTML.
Store the value in a session
session_start();
//form so that you have all the potential forms in a single session array
//form_1 to identify the form in question
if(!empty($_POST)){
$_SESSION['forms']['form_1'] = $_POST;//if this is for the public internet, then I would really consider making sure that the posted data matches the received data... (and that its comming from YOUR form), which is way too long to post here...
}
then on the form page
<input name="flowers" value="<?php echo if(isset($_SESSION['forms']['forms_1']['flowers'])){ echo htmlspecialchars($_SESSION['forms']['forms_1']['flowers']);} ?>" />
obviously the above can be simplified, but for a example's sake it's better this way.
(make sure to clean out the old form data eventually)
You can potentially store the data in the session, and re-populate it back using PHP sessions. You should create a separate back button that takes you to the previous page.
Example:
Storing data:
$_SESSION['data'] = $_POST['item1'];
In the HTML Forms:
<input type="text" name="someinput" value="<?=$_SESSION['data']?>" />
Related
This question already has answers here:
Avoid resending forms on php pages
(6 answers)
Closed 9 years ago.
I have a webpage that contains a form that uses the POST method and references the same page it is on for submission. I am using a PHP include file that contains an if statement that runs when the submit value is set. For some reason though, after one submission, every time you refresh the page it submits the form with the previously submitted data (The browser warns of this before refreshing the page). What causes this, and what could I be doing wrong?
This is expected. You should have the form submit to a handler that has a unique URL, whether it be a query string or a different URI. One solution (of many) would be to change your form action:
<form action="?action=submit" method="post">
<input type="hidden" name="action" value="submit" />
...
and then in the PHP script handle the form, then change the context back to a URL without the hidden query string
if (!empty($_POST['action']) && $_POST['action'] == 'submit') {
// do stuff
header('Location: '.$_SERVER['SCRIPT_NAME']);
die();
}
Note the query string is not actually present in $_POST but we keep it there so browsers don't consider it to be a redirect loop.
i had the same issue with one of my pages.
the reason is that when the browser warns you that it will submit the form again, that means it is going yo be the same exact thing when you click on a submit button.
I did 2 things to avoid it but i am sure there many other ways.
1. Do not let the page echo the form again after succesfull submission of the form.
mine was like this
<?php
if(!isset($_POST['submit'])) {
include(form.php);// you can modify this according to your needs.
} else {
//display your message about what happened with the form.
}
?>
with that approach, your page will not the contaion a form to submit HOWEVER this will not prevent it from submitting on refresh.
2. if the form is submitted create a contoller input that carries a value indication that the form is already submitted. for example , place this into your form:
<?=(isset($_POST['submit']))?"" :"<input type-"hidden" name="submit_stat" value="true" />" ; ?>
and when you process your form when it is submitted check it with your php and make the script act on that variable like this:
<?php
if($_POST['submit_stat']==true) {
//do not process the form here.
//stop your script
}
?>
Another thing you can do is redirect your page to another page other than the page that handles the form. i believe this is the safest one.
Another Way to prevent this is to move the Post Data to Session, redirect, collect Post back from Session and delete Session Post Data.
if(!empty($_POST) && empty($_FILES)){
// move post to session
// redirect to same url (don't forget possible get query)
}else{
// collect post from session
// unset post from session
}
Build this as default and you should never have problems with post data.
Only exceptions are File uploads. In this case redirect *after* post processing manualy.
I'm sending info through a link read in an email via $_GET (i.e. link in email is in form http://website.com?dogs=cats"). But I want the site URL to not have the appendages visible. So I've tried:
Linking to a page which saves the $_GET in a hidden form fields, then automatically submits the form; problem is that the back button then leads back to this intermediary page
Same as above, opening intermediary page in new tab, then having the form load another new tab (_blank), and closes itself; works fine, except in IE these are windows, which are annoying
I'm considering saving the $_GET results in a cookie, then redirecting the page with a header(), then extracting data and expiring the cookie.
Is there an easier way that I'm overlooking?
How about starting a session and storing them to the $_SESSION variables?
Here is a sample implementation of how you can make a hidden arguments on links. This sets a custom handler on the links which will copy hidden argument into the form and send it through post request. It is not a substitute to the session, but it can have it's own uses.
<form id="form" method="post" action="">
<input id="dogs" type=hidden name="dogs">
</form>
Sample link
<script>
$(function(){
$('a').click(function(ev){
ev.preventDefault();
$('#dogs').val($(this).attr('data-dogs'));
$('#form').attr('action',$(this).attr('href')).submit();
}
});
</script>
I have form inputs to send to another page to check on and validate them, and in case of errors I have to redirect the user back to the page where he/she filled the form.
So I need to send the content of $_POST back to refill the inputs to avoid refilling them manually...
How can I do that??
Here are two options:
1) Have the PHP script redirect back to the page with the form, with the form values in the URL as GET variables. You can then use those to refill the form.
2) You can send a POST request via jQuery without requiring the user to leave the page. See here: http://api.jquery.com/jQuery.post/ . With this, you can check the user's input in the PHP script, and only redirect them if their input is valid. This saves you the trouble of refilling the form. You can use it like this:
$.post("myphpscript.php",
{ someData: someValue, someMoreData: anotherValue },
function(returnData) {
// do stuff here on return
});
In myphpscript.php you can get the post values as $_POST["someData"] and $_POST["someMoreData"]. The function is what happens when the PHP script returns, and returnData is what the PHP script echoed.
If I'm correct you want to check your POST-values and if they are invalid input, you want the user to be directed back to the original page and fill the input-fields with the POST-values.
<input type="text" value="<?php echo (isset($_POST["text"] ? $_POST["text"] : "") ?> />
This checks if the POST-var is set, if so, it sets the value of the input-field to the value of the POST-var, else it sets the value to empty
An alternative to excellent answers posted is to store these values into the session and access them from there.
Say I have create a registration form. Now to add records into a DB, we send the data to another php file by POST method, where we do some validations and add a record. Is it possible to do it in the same file without sending and getting the data by POST/GET? If no, then why?
EDIT: Even sending to the same php file is SENDING and losing resource. I ask this question because I want to avoid the lost of time on sending by GET/POST and getting by the same Get/POST. And if it is not posible, I want to understand why PHP does not allow.
No. You always have to send data from the client to the server, there is no way around that.
If you dont want to reload the entire page the user is on, you could submit the data via AJAX to the php file responsible for processing it and adding the data. That way the user never leaves the page.
yes ofcourse.
just in your form "action" put
$_SERVER['PHP_SELF']
then in the beginning of your PHP page check if the $_POST is set or not
if(isset($_POST))
{
// actions to be taken after form submission
}
ofcourse you can add a hidden input tag for refining checks for the $_POST. eg in your form
<input type="hidden" name="formSubmit" value="yes" />
then your check should be like
if(isset($_POST['formSubmit']))
{
// actions to be taken after form submission
}
It's possible. For example:
<?php
if(true === isset($_POST['submit']) // check if submit-button was clicked
{
// do some validation here...
// If validation successes add record into db here...
}
else // no post data sent so output the form
{
// output the form here...
}
Yes it is possible set
action="same page"
in form tag.
you can access your all form attributes on same page.
Yes it is easy. The form can post back to its self. This is most easily done by not even specifying the value of action in the form tag.
<form method='POST'>
Then at the top of the page before any content is put on the page, include an if statement to check if the form was submitted.
if (isset ($_POST['post'])) { // 'post' is the name of the submit button
$error = false;
// Do validation
From there do validation and act according to the result.
If you have lots of validation to do, perhaps put that in another file and include it.
include "formValidation.php";
If all is well and all tests are passed use
if ($error === false) {
Header ("Location: confirmation.php");
exit;
}
}
If tests fail, stay on the page keeping all the post data, and display an error.
if (isset ($error) && !empty ($error)) {
echo "<div class='error'>$error</div>";
}
I have buy.php with a form where you enter items, quantity, shipping data, etc.
When you click the Submit button, it posts back to buy.php ($_SERVER['PHP_SELF']) and does some data validation.
If there are fields missing or errors, they are highlighted. If everything is correct, I save the $_POST data in $_SESSION variables, then do a header('Location: check.php'), where I display the data so the buyer can check the info one last time before actually buying.
Now, if I'm in check.php and hit the Back button to buy.php so I can change stuff, the browser asks if I want to resend the POST data. I'm trying to avoid that.
Anyone have any good advice or good practices for PHP Multiform validation?
Also, if I had n pages for the user to fill, buy.php, buy2.php, ... buyn.php before check.php would the same ideas still hold?
You could do a redirect to buy.php after saving to the session object, which then does a server redirect to check.php, it would mean when the user clicks back, they're going back to the GET request not the POST request
Yes - I agree with above. I ALWAYS do a redir away from the last post, so clicking back bounces them back without that error OR re-submissions. it also avoids complications. u can always tag the redir link page with a ?m or &m (i.e.: page.php?m) and have this at top of page: (use elseif there after)
if (isset($_GET['m'])) {
echo 'order placed.';
}
else {
//...
}
You can have it all on one page too. Just name the submit buttons submit1, submit2, like: (bear in mind if you use an image for submits, it becomes $_POST['submit1_x'] :)
if (isset($_POST[submit1]) {
//validate + save session data from form1
//display form 2
} else if(isset($_POST[submit2])) {
//validate + save session data from form2
//display form 3
} else {
//display first form
//<input type="submit" name="submit1" value="Continue">
}