I'm trying to get a session variable to alternate between 0 and 1 on each page load.
So first time page loads
$_SESSION['turn'] = 0;
Second time
$_SESSION['turn'] = 1;
Third time
`$_SESSION['turn'] = 0;`
and so on.
Then I can call that variable later in the page.
I can't work out how to do this. I've tried a simple IF function but can't get it to work.
First the session must be started on any page wishing to make use of the session array. session_start()
Next you have to remember that initially the session variable you are using will not exist the first time you attempt to use it
So
<?php
session_start();
if ( !isset($_SESSION['turn']) ) {
// does not exist yet, so create with 0
// you may want to initialize it to 1, thats up to you
$_SESSION['turn'] = 0;
} else {
$_SESSION['turn'] = $_SESSION['turn'] == 0 ? 1 : 0;
}
Try this where the page is loaded.
$_SESSION['turn']=1-$_SESSION['turn'];
code:
<?php
session_start();
echo $_SESSION['turn'];
$_SESSION['turn']=1-$_SESSION['turn'];
?>
Edit : RiggsFolly !isset() is correct. mine misses it and it will give errors in log. and the first value is not 0
Related
How to access the incremented value of session on the same page where we have defined the initial value of session, I am using this method for incrementation of value but on another page
<?php
$_SESSION['indexValue'] = 1;
?>
This is my test.php page where i have decrelaed the inital value of session.
<?php
$Incrementvalue = $_SESSION['indexValue'];
$counter = (int)$Incrementvalue;
if ($counter=$counter) {
$counter++;
$_SESSION['indexValue'] = $counter;
}
echo "$_SESSION['indexValue']";
?>
This is my getdata.php page where I have implmented the increment value function. Now i have to pass this increment value of Session again on test.php page . How can I perform this?
your code seems not to be thought off
first of all, you need to call session_start() at beginning
then you can access everyewhere your $_SESSION variable (if you call session_start() before)
if ($counter=$counter) {
$counter++;
$_SESSION['indexValue'] = $counter;
}
this seems useless
$_SESSION['indexValue']++;
is enough
First of all there are few errors in code like
if ($counter=$counter) should be if ($counter == $counter)
And
echo "$_SESSION['indexValue']" should be echo $_SESSION['indexValue'].
Now answer to your question is that session is accessible anywhere throughout the project/application. So you need not to pass it , just access it as $_SESSION['indexValue'].
I have a problem with sessions in wordpress. First I've activated the use of sessions in my functions.php and no I get the right variable but just after I reload my target site after setting the variable. When I load another page first and my target page seacondly my variable has a wrong value without any context to my first value. When I have the right value on my target site and I reload this site the value is also wrong. This is my code:
//Activate sessions() in functions.php
add_action('init', function(){
if(!session_id())
{
session_start();
}
}, 1);
//Calculate the variable
$gesamtumsatz_kcal = round (($value1 + $value2 + $value3), 0);
//Then set the session variable
$_SESSION['gesamtumsatz_kcal'] = $gesamtumsatz_kcal;
//Get my session variable on another page somewhere on my site
if(isset($_SESSION['gesamtumsatz_kcal'])) {
$gesamtumsatz_kcal = $_SESSION['gesamtumsatz_kcal'];
} else {
$gesamtumsatz_kcal = '';
}
//Echo my variable
echo $gesamtumsatz_kcal;
Do you have any idea whats wrong? I'm absolutely at the end with this....
Thanks a lot!
I have to add this
When I define a constant variable without calculate something like this:
//Define the variable
$_SESSION['test'] = 1056;
//Get the variable
$test = $_SESSION['test'];
//Echo the variable
echo $test;
I always get the right value: 1056 back... What is this? Can't uderstand
wordpres destroys session when it is not opened. so use
if(!session_id()) session_start();
in the start of wp-config.php or better in the init of your code/plugin
I have a form sender which is posting a value of 6 to another form receiver. What I'm trying to achieve is store the posted value from sender into a variable in the receiverthen increment the variable it every time the sender posts. Then print the updated variable
This is what I have tried to do
$val= $_POST['val'];
$limit = 6 + $val;
echo $limit;
Im getting the result as 12. But what I want is
After first post result = 12
After second post result = 18
On and on...
NB:$_POST['val'] = 6;
session_start();
$limit = 6;
if(!isset($_SESSION['lastLimit'])) {
$_SESSION['lastLimit'] = 0;
}
if(!empty($_POST)) {
$_SESSION['lastLimit'] = $_SESSION['lastLimit'] + $limit;
$postedValue = $_POST['val'] + $_SESSION['lastLimit'];
echo $postedValue;
}
Because the web is stateless i.e. scripts do not remember anything that happened the last time a page/form was executed the receiver script does not remember anything from the last time it was run.
But dont panic, there is a way. Its called a SESSION and you can store data in the session which will then be available the next time this user connects to your site. In PHP you use it like this. The session is linked to this specific connection to a specific user.
receiver.php
<?php
// must be run at top of script, before any output is sent to the new form
session_start();
// did the form get posted and is the variable present
// or replace POST with GET if you are using an anchor to run the script
if ( $_SERVER['REQUEST_METHOD'] == 'POST' && isset($_POST['val']) {
if ( isset($_SESSION['limit'] ){
// increment the limit
$_SESSION['limit'] += (int)$_POST['val'];
} else {
// initialize the limit
$_SESSION['limit'] = (int)$_POST['val'];
}
echo 'Current value of limit is = ' $_SESSION['limit'];
} else {
// something is not right
// direct this user to some basic page like the homepage or a login
header('Location: index.php');
}
You need an intermediate layer to store the value.
Available options:
1) Global static value
2) session
3) file
4) database
I would recommend global value or session, as they data you want to store isn't that huge and would meet the requirements easily.
I would not write the syntax to store it in session as a number of people have already mentioned it. I just wanted to clarify the problem scenario and possible solutions.
You can store $limti into global varibale .
global $val;
$val += $_POST['val'];
$limit = 6 + $val;
echo $limit;
I have a session variable that is updated when a link is clicked which adds GET variables to the current URL:
<?php
$_SESSION['test'] = 0;
if (isset($_GET['do'] && $_GET['do'] == 'this')) {
$_SESSION['test'] = $_SESSION['test'] + 1;
}
echo $_SESSION['test'];
?>
Click me
When the link is clicked, the new session value that is echoed is still 0.
Why? How do I get this to echo the updated value? (1)
EDIT: Yes, session_start() is included at the top of the page.
change it to be like this:
<?php
session_start();
if(!array_key_exists('test', $_SESSION)){
$_SESSION['test'] = 0;
}
if(array_key_exists('do', $_GET) && $_GET['do'] === 'this') {
$_SESSION['test']++;
}
echo $_SESSION['test'];
?>
Click me
I like array_key_exists() more than isset because the key can exist being null and still pass the test:
From the php docs: "isset() does not return TRUE for array keys that correspond to a NULL value, while array_key_exists() does."
You also were using isset incorrectly to test the contents of $_GET['do']. To top things off, you didn't start the session on each page load.
session_start() will initialize the $_SESSION variable and fill it with the appropriate contents. Since this was not in your code, the $_SESSION variable never had your 'do' key.
The second-to-last problem you had was the very first line, you were always setting the 'test' key to 0 causing the outcome to always be 1 after clicking Click me
and finally, you didn't close the php tag prior to outputting raw HTML which should have given you an error
Maybe you have not paste the whole code but here is how it should have been done.
<?php
session_start();
$_SESSION['test'] = 0;
if (isset($_GET['do']) && $_GET['do'] == 'this') {
$_SESSION['test'] += 1;
}
echo $_SESSION['test'];
?>
Click me
You need to start with session_start() Google to learn more about it.
You have put everything in the isset() Google isset() to learn more about it.
you need to close php tags before you can insert raw HTML. Inside HTML you can execute php with <?php ?> tags.
Hope this helps.
As mentioned before, you have everything wrapped in isset() should be
isset($_GET['do'])
not
isset($_GET['do']
Also, you're session is always being set to 0 on each page refresh. You need to only set $_SESSION['test'] = 0 if $_SESSION['test'] has not been set yet.
if (!isset($_SESSION['test'])) {
$_SESSION['test'] = 0;
}
You are missing session_start() at the top of your script. You're also not assigning the session if it doesn't previously exist, you're continuously setting it to 0 before incrementing.
I am redirecting to a different page with Querystring, say
header('location:abc.php?var=1');
I am able to display a message on the redirected page with the help of querystring value by using the following code, say
if (isset ($_GET['var']))
{
if ($_GET['var']==1)
{
echo 'Done';
}
}
But my problem is that the message keeps on displaying even on refreshing the page. Thus I want that the message should get removed on page refresh i.e. the value or the querystring should not exist in the url on refresh.
Thanks in advance.
You cannot "remove a query parameter on refresh". "Refresh" means the browser requests the same URL again, there's no specific event that is triggered on a refresh that would let you distinguish it from a regular page request.
Therefore, the only option to get rid of the query parameter is to redirect to a different URL after the message has been displayed. Say, using Javascript you redirect to a different page after 10 seconds or so. This significantly changes the user experience though and doesn't really solve the problem.
Option two is to save the message in a server-side session and display it once. E.g., something like:
if (isset($_SESSION['message'])) {
echo $_SESSION['message'];
unset($_SESSION['message']);
}
This can cause confusion with parallel requests though, but is mostly negligible.
Option three would be a combination of both: you save the message in the session with some unique token, then pass that token in the URL, then display the message once. E.g.:
if (isset($_GET['message'], $_SESSION['messages'][$_GET['message']])) {
echo $_SESSION['messages'][$_GET['message']];
unset($_SESSION['messages'][$_GET['message']]);
}
Better use a session instead
Assign the value to a session var
$_SESSION['whatever'] = 1;
On the next page, use it and later unset it
if(isset($_SESSION['whatever']) && $_SESSION['whatever'] == 1) {
//Do whatever you want to do here
unset($_SESSION['whatever']); //And at the end you can unset the var
}
This will be a safer alternative as it will save you from sanitizing the get value and also the value will be hidden from the users
There's an elegant JavaScript solution. If the browser supports history.replaceState (http://caniuse.com/#feat=history) you can simply call window.history.replaceState(Object, Title, URL) and replace the current entry in the browser history with a clean URL. The querystring will no longer be used on either refresh or back/previous buttons.
When the message prompt ask for a non exsisting session. If false, show the message, if true, do nothing. session_start(); is only needed, if there is no one startet before.
session_start();
if ($_GET['var']==1 && !isset($_SESSION['message_shown']))
{
$_SESSION['message_shown'] = 1;
echo 'Done';
}
Try this way [Using Sessions]
<?php
//abc.php
session_start();
if (isset ($_GET['var']))
{
if ($_GET['var']==1)
{
if(isset($_SESSION['views']))
{
//$_SESSION['views']=1;
}
else
{
echo 'Done';
$_SESSION['views']=1;
}
}
}
?>
Think the question mean something like this?
$uri_req = trim($_SERVER['REQUEST_URI']);
if(!empty($_SERVER['REQUEST_URI'])){
$new_uri_req = str_replace('?avar=1', '?', $uri_req);
$new_uri_req = str_replace('&avar=1', '', $new_uri_req);
$pos = strpos($new_uri_req, '?&');
if ($pos !== false) {
$new_uri_req = str_replace('?&', '?', $new_uri_req);
}
}
if( strrchr($new_uri_req, "?") == '?' ){
$new_uri_req = substr($new_uri_req, 0, -1);
}
echo $new_uri_req; exit;
You can use then the url to redirect without vars. You can also do the same in js.
str_replace() can pass array of values to be replaced. First two calls to str_replace() can be unified, and filled with as many vars you like that needs to be removed. Also note that with preg_replace() you can use regexp that can so manage any passed var which value may change. Cheers!