How To Set A PHP GET Variable If It's Not Set - php

This is what I have.
<?php
if (isset($_GET["var"])) {
echo "1";
} else {
echo "1";
}?>
I want it to check if there's been a variable set for "var" and if there isn't (which will happen the first time anyone goes to site), I want it to be set to "1". Then I want to create buttons "back" and "forward" that will will increase "var" by "1" until it reaches my limit of "10" then returns to one.
I can figure out the math and buttons part, I just need help initially setting "var" since it isn't already set when you go to the page.

Aside from architecture, security and any other issues:
$_GET is just a simple array accessible from anywhere in script.
$_GET['var'] = 'foo';
Docs: http://www.php.net/manual/en/language.variables.superglobals.php

Try this tag
<a her="www.example.com?var=<?php echo $get_var?>">your site name</a>

the get variables come in to the script like so
scriptname.php?getvar=val
To "set" the variable you would need to test for it, Increment it and redirect too it
$var = 1;
if (isset($_GET['var'])){
$var = (int) ($_GET['var'] +1);
if($var > 10) {
$var =1;
}
}
header("Location: " . $_SERVER['PHP_SELF'] ."?var=" . $var);
as mentioned in the comments, SESSION is a much better place to store this information

Related

How to access increment value of session on same page in php

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'].

Only change session variable if GET request has value

I am looking to set a session variable based on a search conducted by the user. The idea is that the search is populated with their last search wherever they go on the site.
I have the following code that I thought would set the variable if the variable geo-box was present and use the saved variable if it isn't, but this doesn't work...
session_start();
if(isset($_GET['geo-box'])){
echo $_SESSION['town'] = $_GET['geo-box'];
} else {
echo $_SESSION['town'];
}
session_start();
if(isset($_GET['geo-box']))
$_SESSION['town'] = $_GET['geo-box'];
echo $_SESSION['town'];
You can't echo a variable while defining it.
Best of Luck!
You are trying to echo a variable and set it in the same line.
Try this:
session_start();
if( isset($_GET['geo-box']) ) {
$_SESSION['town'] = $_GET['geo-box'];
}
echo $_SESSION['town'];
You can not echo a value and assign it at the same time. Give this a try!
Hope this helps.

Need help conditionally including php in page

I've been trying to conditionally include a banner which incorporates a form into a php site. Previously the banner was part of the header but I need to exclude it from certain pages in order for other elements to be included.
I'm using $_SERVER['SCRIPT_NAME'] to define a variable on the page and then check for this. I'm a little confused though as to where the variable should be placed. Will it work if placed in the header or does it need to be included in every separate page?
This is what I've got:
<?php $currentPage = $_SERVER['SCRIPT_NAME']; ?>
<?php if ($currentPage != "/ecoProcess.php") {
include ("includes/banner.php");
} else {
echo "ECO";
}
?>
For further info, I've updated the code because of my schoolboy error with -= instead of != but neither of the conditions works now (no banner, no "ECO"). The pages are being called using this method:
<?php if($_GET['action']=='boiler_installation_replacement') {?> class="active"<? php } ?>>Boiler Installation and Replacement
I've been advised to try var_dump which reveals this:
' string(14) "/ths/index.php" ' everytime. I guess this is due to the way the pages are called but I don't know how to get around this.
-= means subtract right value from left side. Eg.
$a = 5;
$a -= 3;
echo $a; // will print 2 because 5 - 3 = 2 :)
Change it to comparison == or better ===. You can also use !=/ !== for opposite cases.
Change your condition like this.
<?php
$currentPage = $_SERVER['SCRIPT_NAME'];
if ($currentPage == "/ecoProcess.php") {
include ("includes/banner.php");
} else {
echo "ECO";
}
?>
Try this:
just change your if statement because it is not logically correct.
Use this
if ($currentPage == "/ecoProcess.php")
instead of
if ($currentPage -= "/ecoProcess.php")
Thanks

Remove querystring value on page refresh

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!

PHP - Manually Set And Then Echo $_GET Data

How would I for example, take a url with some $_GET data, for example http://www.website.com/something?food=steak
How would I then output steak? My current situation is that I'm trying to use the Header function to redirect to a page where I have it so that if $_GET["duplicate"] is equal to 1, then echo this, else, echo nothing. But its not taking the $_GET data I can tell I did a var_dump($_GET);
<?PHP if ($_GET["duplicate"] == 1 )
{
echo "<h1>Username Taken!</h1>";
}
else
{
echo "";
}
?>
The above is using the url http://something.com/register?duplicate=1
It's just a variable, treat it like one:
echo $_GET['food'];
Everything after question mark is available in form of global array $_GET.
$a=$_GET["food"];
echo $a;
also
if url has ?food=steak&color=red;
$a=$_GET["food"];
$b=$_GET["color"];
more than one is possible. Also search for $_POST.
Alright, so I figured my issue out. I have a $_GET variable that gets the end of the page and declares it as "p" for page. I need to do the following to get it to work.
?p=createuser&duplicate=1

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