Editing and creating things with address bar code? - php

How do I make it so that I can make a thing at the end of the address where the .php is and then tell it to do certain things. For example pull up a page like this:
sampardee.com/index.php?page=whatever
Help?
Anything else I could do with this?

This is generally achieved with the global php array $_GET. You can use it as an associative array to 'get' whatever variable you name in the url. For example your url above:
//this gives the $page variable the value 'whatever'
$page = $_GET['page'];
if($page == 'whatever'){
//do whatever
}
elseif($page == 'somethingelse'){
//do something else
}
Check out the php documentation for more information:
$_GET documentation
and there's a tutorial here:
Tutorial using QUERY_STRING and _GET

A small improvement over Brett's code:
if (array_key_exists('page', $_GET) === false)
{
$_GET['page'] = 'defaultPage';
}
$page = $_GET['page'];
// ... Brett Bender's code here

$_GET is usually used if you are sending the information to another page using the URL.
$_POST is usually used if you are sending the information from a form.
If you ever need to write your code so that it can accept information sent using both methods, you can use $_REQUEST. Make sure you check what information is being sent though, especially if you are using it with a database.
From your question it looks like you are using this to display different content on the page?
Perhaps you want to use something like a switch to allow only certain page names to be used?
i.e.
$pageName=$_REQUEST['page'];
switch($pageName){
case 'home':$include='home.php';break;
case 'about':$include='about.php';break;
case default:$include='error.php';break;
}
include($include);
This is a really simplified example, but unless the $page variable is either home or about, the website will display an error page.
Hope it helps!

I'm not quite sure what you're asking, but I think you're asking how to use GET requests.
Make GET requests against any PHP page as follows:
www.mysite.com/page.php?key1=value1&key2=value2
Now, from within PHP, you'll be able to see key1 -> value1, key2 -> value2.
Access the GET hash from within PHP as follows:
$myVal1 = $_GET['key1'] #resolves to "value1"
$myVal2 = $_GET['key2'] #resolves to "value2"
From here, play with your GET variables as you see fit.

The system of adding page parameters to a URL is know as HTTP GET (as distinct from HTTP POST, and some others less commonly used).
Take a look at this W3 schools page about GET in PHP and ahve a play about in getting parameters and using them in your PHP code.
Have fun!

Related

PHP get previous page url after redirect

I want to have a navigation bar that tells the user where they just came from.
Example: Homepage -> Post
But if they are in their posts manager and click on a post, I want it to say
Posts manager -> Post
I read that $_SERVER['HTTP_REFERER'] is not good enough to get the full url so that's not useful as I want the navigation bar all clickable
Any help is much appreciated!
I believe what you want is called breadcrumbs.
What to use for navigation chain storage is actually up to you. You might use even $_SERVER['HTTP_REFERER'] if you want, but that'd be unreliable as it's client-side. Usual way to store such chain is actual URI or session.
For example, you have such URI: http://www.example.com/post_manager/post
Then you can iterate through explode("/", $_SERVER["REQUEST_URI"]) to get each step.
That's basic explanation to guide you to a right direction. You can google alot of samples and snippets using keyword breadcrumbs.
On the topic of saving last visited location (the way to determine wether abonent came from manager or homepage): you can use session's variables to do that. Here's an example:
This way you can set a variable on your homepage:
<?php
session_start();
$_SESSION['previous_location'] = 'homepage';
?>
And then you just access it from another page:
<?php
$previous_location = $_SESSION['previous_location'];
?>
It's important to set session.save_path in your PHP configuration file or your sessions might get lost.
You could do it on the client side if you use the Javascript document.referrer property. However, a better solution may be to use the global session array.
if (!isset($_SESSION['referrer'])) {
$_SESSION['referrer'] = $current_uri;
} else {
$previous_uri = $_SESSION['referrer'];
$_SESSION['referrer'] = $current_uri;
}
The best solution IMO is to save the location into session, every time the user goes to a 'meaningful' page (that you want to be able to navigate back to via this feature), then simply use this array of, say, last 2 visited pages to pull up all the information. Simple and effective.
<?php
session_start();
$_SESSION['user_interactions'][] = $_SERVER['HTTP_REFERER'];
// get previous
$previous_page = end($_SESSION['user_interactions']);
// list all user interactions
foreach($_SESSION['user_interactions'] as $key => $value){
echo $value;
if(count($_SESSION['user_interactions'])-1 != $key) echo ">";
}
?>

Hide PHP Variables in URL with url rewrite

I am working on a site that has to deal with reservation numbers and I need to pass variables to confirmation page. Currently when you arrive at confirmation.php the URL looks something like the below:
http://localhost/confirmation.php?reservation_id=1&proceed=no
These variables are sent via a link to this page from the index page. I need a way to either encrypt the $reservation_id OR rewrite my URL so it looks like this
http://localhost/confirmation.php
...but still have access to my variables. I have tried sessions and some encryption methods, but cant find anything that wont over complicate the page as I am trying to keep it as simple as possible. Forms with hidden fields is not an option, I am printing all the reservations in links with a loop from the database.
Thanks!
Use session variables. Create a random session variable name, and assign the reservation information to it:
foreach ($reservations as $r) {
$random = make_random_string(); // You need to write this function
$_SESSION[$random] = $r;
echo "<a href='reservation.php?id=$random'>...</a>";
}
Then reservation.php can look up $_SESSION[$_GET['id']] to get the reservation information.
It sounds like you need to start a session and pass the data in there. Or, you could POST the data instead (Use a form). But the session is probably the better choice.

How do I use php?=

I'm kind of a noob at this stuff.
But I've been browsing around and I see sites that are kind alike this
www.store.com/product.php?id=123
this is really cool. but How do I do it?
Im stuck using something like this
www.store.com/product/product123.php
If you could tell me how I can go about do this it would be awesome!
What you're looking at is a $_GET argument.
In your PHP code, try writing something like this:
$value = $_GET['foo'];
Then open your page like this:
hello.php?foo=123
This will set $value to 123.
You need to use the $_GET here.
if you use the following:
?id=123
then this will be how to use it and the result
$_GET['id'] (returns the 123)
You can use as many $_GET arguments as you need, for example:
?id=123&foo=bar&type=product
$_GET is an array of what parameters are in the url, so you use it the same way as an array.
Create a file called product.php with this code:
<?php
echo "The argument you passed was: " . $_GET['id'];
?>
Now run this URL in your browser:
http://<yourdomain>/product.php?id=123
and you will understand how $_GET works.
Those are called URL parameters (what they're contained in is called a query string), and they're not unique to PHP but can be accessed in PHP using the $_GET superglobal.
Similarly, you can get POST parameters using the $_POST superglobal, though in POST requests, these parameters are not appended to the URL.
Note: Generally, for usability purposes (and thus also SEO purposes), you want to avoid using query strings as much as possible. These days, the standard practice is to use URL rewriting to display friendly URLs to the user. So your application might accept a URL like:
/products.php?id=32
But the user only sees:
/product/32
You can do this by using mod_rewrite or similar URL rewriting capabilities to turn the friendly URL into the former query string URL internally, without having the user type out the query string.
You might want to have a look at the documentation at www.php.net, especially these pages: http://www.php.net/manual/en/reserved.variables.php
Specifically, have a look at $_GET and $_POST, which are two frequently used ways to transmit information from a browser to the server. (In short, GET-parameters are specified in the URL, as in your question, while POST-parameters are "hidden from view", but can contain more data - typically the contents of forms etc, such as the textbox you posted your question in).

Hide ?ref string in URL but pass it to script

How can I hide ?ref string from users but pass it to php code so it will grab it?
For example, visitor visits this page:
http://mysite.com/?ref=ref+string
In browser URL I want to hide it, so user will see"
http://mysite.com/
But I want to grab content of ref string via this:
$ref = $_GET['ref'];
Is it possible?
No, if you want to use GET variables, they will always be in the url.
However, you can use an alternative, like $_SESSION or $_POST variables.
You could try something like this at the top of your PHP script:
session_start();
if (isset($_GET['ref'])) {
$_SESSION['ref'] = $_GET['ref'];
header('Location: /');
exit();
}
You would have to use $_SESSION['ref'] to access the value from then on, however.
This is not how the http protocol works with query strings. If you have information that needs to be in the query string that you want to hide or obfuscate from the user, I would recommend a simple encryption to change it. If you're attempting to get rid of this information for aesthetic reasons, you will need to pursue a different method of generating the header or storing the information (session/cookies/etc).

php/html - http_referer

I am creating a website and on one particular page, am wanting to send the user back to the previous page. I am fairly new to PHP/HTML and have been using some existing code for ideas and help.
The existing code uses the following method:
if (! empty($HTTP_REFERER))
{
header("Location: $HTTP_REFERER");
} else
{
header("Location: $CFG->wwwroot");
}
However, when I use this code the HTTP_referer is always treated as empty and the user redirected to the root page. Any obvious flaws in this code?
Don't rely on the HTTP Referrer being a valid or even non-empty field. People can choose to not have this set leaving any checks for that variable going to the empty side of the IF-ELSE clause.
You can guard against this by sending along a parameter in either the URL or POST parameters that would hold a value that you can use to redirect the user back to.
You need to use:
$_SERVER['HTTP_REFERER']
isset($_SERVER['HTTP_REFERER']) ? $_SERVER['HTTP_REFERER'] : '';
If you wanted to send the person back to the previous page and have it work regardless of the referrer being set correctly, you can append a GET parameter to the URL (or POST).. you will need to encode the URL.. Something like
http://www.domain.com.au/script.php?return=http%3a%2f%2fwww.domain.com.au%2fthis-is-where-i-was%2f
You can use PHP's urlencode() function.
Also note that the referer header might be empty or missing anyway, so you shouldn't rely on it at all..
You should use
$_SERVER['HTTP_REFERER']
However look at the register_globals configuration in php.ini, it should be turned off due to security reasons. You can read more on PHP Manual site.

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