I'm sure this is a rookie question but I get undefined index in the $_POST password parameter.
if ($_SESSION['Password'] == $_POST['Password']){
echo 'Hi 2 '.$_SESSION['Password'].'<br>';
}
If I do the following with either with $_SESSION or $_POST, I get the correct echo line.
if (!empty($_SESSION['Password'])){
echo 'Hi 2 '.$_SESSION['Password'].'<br>';
}
Can it be that same parameters cannot be used for both variables ?
First you should understand what is SESSION and POST variables.
SESSION is used to store a session variable that can be accessed throughout the session from any PHP document. POST is used to get any variable that send through the post method.
In the first code snippet you are checking weather the
SESSION['Password'] == POST['Password']
and you are not providing any value through post method and the post variable 'Password' is not defined in your program to that's why you are getting an undefined error.
So to over come this one the best way is to check weather both of the variable has defined or not by using isset function.
if(isset($_SESSION['Password']) && isset($_POST['Password'])){
if ($_SESSION['Password'] == $_POST['Password']){
echo 'Hi 2 '.$_SESSION['Password'].'<br>';
}
}
Provide the value for POST['Password'] through a correct statement then the code will work.
I think you know how to set values for SESSION variable because you are comparing a SESSION variable with a POST variable.
Related
I was trying to pass an error message to another page using session variable. On the handler page, the session was initialized in the manner:
function sess() {
$index = $_POST['name'];
$_SESSION['error'] = ($index == '') ? 'name cannot be empty' : $index . " is a good name";
header("Location: http://website-name.com/form");
}; sess();
and on the other page is something like:
if(isset($_SESSION['error'])) {
echo $_SESSION['error']; unset($_SESSION['error']);
};
Now if the form is submitted with an empty field, the error name cannot be empty becomes the value of the session. After that, if the name is then set, the value of the session doesn't change but still returns name cannot be empty.
I've checked to see if it has something to do with the fact that the session was called within a function. got no idea! but found online a way to unset all variable using session_unset. But it's actually one session variable that i want to unset and i found something like session_unset($_SESSION['error']). However, using it did not unset all session but the $_SESSION['error'] doesn't get set anymore within the function unless i use the unset($_SESSION['error']) which doesn't terminate the first session that is set.
So what is actually going wrong? how does unset_session() works differently form unset()? what does it has to do with being inside a function? As far as i can recall, $_SESSION[] is a global variable just like $GLOBALS[] which can be access in any scope.
I am wondering why: without clicking the submit button on a form on my PHP page, the _POST variable is already set.
For example, I have this piece of code on the web page:
if (isset($_POST)){
echo "XXXXXXX";
}
It turns out the XXXXXX is echoed just when the page loads the very first time -- at this point I have of course not submitted any data to the server using POST. Why would this be the case?
As specified on PHP.net, it is automatically created.
This is a 'superglobal', or automatic global, variable. This simply means that it is available in all scopes throughout a script. There is no need to do global $variable; to access it within functions or methods.
To address your code, it is created, but it's empty.
To better test if the user has made a POST request, simply test for an index on $_POST, like isset($_POST['someFieldName'])
Your code should test if it's empty or not:
if(!empty($_POST)){
echo "a";
}
or
if(isset($_POST['someFieldName'])){
echo "a";
}
$_POST is a superglobal array and it is always set. If you do not pass any value to it using post method it will be empty. So set a value to this array and check whether that value is available or not like this:
if(isset($_POST['submit'])){
//Do this...
}
The same is true for the $_GET superglobal. These are always set regardless of HTTP Method. You can check if a request was a POST, GET, PUT, etc by checking the REQUEST_METHOD
if ($_SERVER['REQUEST_METHOD'] == 'POST') {
// this was an HTTP POST request
}
Check if the variable is empty or not. $_POST will always be set.
So something like the following should work:
if(!empty($_POST['textFieldName'])){
echo "XXXXXXX";
}
$_POST is superglobal and it's always set as an empty array.
Try this, just to understand better:
if(!is_null($_POST))
{
print_r($_POST);
}
Why is this going to help you to understand? - Because isset checking if a variable is set and is not NULL.
I'm trying to only display some content if values were posted to my page. I'm doing this using the following code:
if(isset($_POST)){
echo "it is in here";
}
The value in the echo is appearing even when the page loads, why would that be?
$_POST are always set, try empty function instead. Try this:
if(!empty($_POST)){
echo "it is in here";
}
$_POST is one of the superglobals in PHP Superglobals - PHP Manual
isset() will return TRUE on any of them, since they are
built-in variables that are always available in all scopes
according to the official manual.
You should either check
isset($_POST['a specific post parameter name'])
Or, check:
$_SERVER['REQUEST_METHOD'] === 'POST'
to determine.
$_POST isset even if it's empty
You can use !empty (not empty), i.e.:
if(!empty($_POST)){
echo "it is in here";
}
Although, you should normally check if a specific $_POST parameter isset, i.e.:
if(isset($_POST["something"])){
echo "something is in here";
}
Resources:
function.empty
reserved.variables.post
function.isset
Can some explain to me the best way to store a $_GET variable in a session and the only way the sessions changes is when we verify the data the session is being change to is different from the GET variable.
Currently i have
$tid = clean_get($_GET['tid']);
in a global file which is included on every page the problem with that is the value of $tid will be erased and not stored in a session like i want it to once the user is not on a page with $tid set in the url.
If you get $_GET['tid'] in url then set session again by that new value otherwise restore it from session. Thats it.
session_start();
$tid = (isset($_GET['tid']) && $_GET['tid']!="") ? clean_get($_GET['tid']) : $_SESSION['tid'];
Try this and tell me is it solved?
Use a function like isset() to see if it is being sent. Only then should you replace it:
if(isset($_GET['tid']))
{
$tid = clean_get($_GET['tid'])
// Do stuff to change session data.
}
I think what you are looking for is something like
session_start();
foreach ($_GET as $key=>$value) {
$_SESSION['getValues'][$key] = clean_get($value);
}
This will store all the values in $_GET in the $_SESSION. To retrieve the values later, you just have to use $_SESSION['getValues']['tid'] after calling session_start().
Here I'm assuming that clean_get() is just something that formats and/or escapes data that came in from forms, so calling it on each value before sticking into the session will do all that cleaning when needed.
Note: only call session_start() once, and make sure you do so before doing anything with $_SESSION, otherwise you'll get error messages.
I am developing a php script which contains an html form.
If not all fields are filled in the correct way the script will signal an error and redirect back to the same page with the header function setting an error variable to yes with the get method:
header("Location: registration_page.php?error_empty=yes");
my script has an error handling part in which it highlights the fields containing a mistake, but I would like to keep the value of the fields correctly filled.
I am implementing this feature as I found in this other question:
How can I keep a value in a text input after a submit occurs?
but the problem is that when the page reopens the forms will not contain the old values.
My question is: does anybody know if the header function unsets global variables in the $_REQUEST array?
And do you know what kind of solution could I adopt?Maybe sessions?
Thanks in advance,
Matteo!
$_COOKIES will stay set, but $_POST & $_GET will be destroyed, as the client is moving to a new page. If they need to be retained, they must first be stored into $_SESSION before calling the redirect.
session_start();
$_SESSION['last_post'] = $_POST;
header("Location: http://example.com");
exit();
// On the redirected page, use the stored POST values and unset them in $_SESSION
session_start();
if (empty($_POST) && isset($_SESSION['last_post'])) {
$post = $_SESSION['last_post'];
unset($_SESSION['last_post']);
}
else $post = $_POST;
Does anybody know if the header function unsets global variables in the $_REQUEST array?
No, it doesn't. Cookies ($_COOKIE) will remain.
Obviously $_GET will contain whatever you have in the redirect (eg: $_GET['error_empty'] = 'yes') and$_POST` will be empty because you aren't posting.
So it $_REQUEST will be a combination of $_COOKIE and the new $_GET parameters you set.
You probably shouldn't be using $_REQUEST anyway. Specify exactly where you expect your request parameters to be...
It doesn't, but it does make a new request. A new request means a new $_REQUEST which does not necessarily have all of the old data. $_COOKIE will still be there but $_GET and $_POST will be new meaning that $_REQUEST will reflect that. ($_FILES will also be empty and while it is not in `$_REQUEST, it is another user-supplied value will be reset).
If you want to restore the form, you'll need to either put all of the variables in the url in the header, or use $_SESSION or setcookie and then restore from $_GET, $_SESSION or $_COOKIES.