[SOLVED] PHP Session variable value doesn't retrieved to another page

Q. PHP Session variable value is not transfering?

So, you are having trouble with php session variables! Well, Let see how can it being solved! If you didn't read about PHP Session variables then have a look on the manual!

Well let see what is happening...

PHP file: <test1.php>

<?PHP
session_start();

header("Access-Control-Allow-Origin: *"); 
header("Content-Type: application/json; charset=UTF-8");

//some code to determine $approvedToSet
$approvedToSet = true;
if(isset($approvedToSet))
{
$_SESSION["userName"] = 'MyName'; 
echo " Session variable is set." .$_SESSION["userName"];
} 
else { 
echo "User name is not set";} 

?>

PHP file: <test2.php>

<?PHP
echo $_SESSION["userName"];

ERROR:

Notice: Undefined index: userName in /var/www/xyz on line 30



[Solution:]

Correct Your file and ensure session_start(); function is on the top of your page.

PHP file: <test2.php>

<?PHP
session_start()
echo $_SESSION["userName"]; ?>

1. Stop your apache2 or http server and start it again!
2. Ensure session.save_path has been set.
3. Must be Make sure session_start(); is called before any sessions are being called. So a safe bet would be to put it at the beginning of your page, immediately after the opening <?php tag before anything else. Also ensure there are no whitespaces/tabs before the opening <?phptag.
4. After the header redirect, end the current script using exit(); (Others have also suggestedsession_write_close(); and session_regenerate_id(true), you can try those as well, but I'd use exit();).
5. Make sure cookies are enabled in the browser you are using to test it on.
6. Ensure register_globals is off, you can check this on the php.ini file and also using phpinfo(). Refer to this as to how to turn it off.
7. Make sure you didn't delete or empty the session.
8. Make sure the key in your $_SESSION superglobal array is not overwritten anywhere.
9. Make sure you redirect to the same domain. So redirecting from a www.yourdomain.com to yourdomain.com doesn't carry the session forward.
10. Make sure your file extension is .php (it happens!).
11. If you use a connection script, dont forget to use start_session(); at the connection too, had some trouble before noticing that issue.

iu

Tags: coding → debugging → error → novice coding → novice debug → php concept → solution

[SOLVED] PHP Session variable value doesn't retrieved to another page

By Game Changer → Friday, May 5, 2017

The best method to merge PHP objects

We have two PHP5 objects and would like to merge the content of one into the second. There are no notion of subclasses between them so the solutions described in the following topic cannot apply.

Remarks:

• Remember these are objects, not classes.
• Objects will contain quite a lot of fields so a ``foreach`` would be quite slow.
• So far we consider transforming objects A and B into arrays then merging them using array_merge() before re-transforming into an object but we can't say we are proud if this.

If your objects only contain fields (no methods), this works:

$obj_merged = (object) array_merge((array) $obj1, (array) $obj2);

This actually also works when objects have methods. (tested with PHP 5.3 and 5.6)

Another Way:

foreach($objectA as $k => $v) $objectB->$k = $v;

• Specify reference or clone
• Specify first or last entry to take precedence
• Multiple (more than two) object merging with syntax similarity to array_merge
• Method linking: $obj->f1()->f2()->f3()...
• Dynamic composites: $obj->merge(...) /* work here */ $obj->merge(...)

class Compositor {

    protected $composite = array();
    protected $use_reference;
    protected $first_precedence;

    /**
     * __construct, Constructor
     *
     * Used to set options.
     *
     * @param bool $use_reference whether to use a reference (TRUE) or to copy the object (FALSE) [default]
     * @param bool $first_precedence whether the first entry takes precedence (TRUE) or last entry takes precedence (FALSE) [default]
     */
    public function __construct($use_reference = FALSE, $first_precedence = FALSE) {
        // Use a reference
        $this->use_reference = $use_reference === TRUE ? TRUE : FALSE;
        $this->first_precedence = $first_precedence === TRUE ? TRUE : FALSE;

    }

    /**
     * Merge, used to merge multiple objects stored in an array
     *
     * This is used to *start* the merge or to merge an array of objects.
     * It is not needed to start the merge, but visually is nice.
     *
     * @param object[]|object $objects array of objects to merge or a single object
     * @return object the instance to enable linking
     */

    public function & merge() {
        $objects = func_get_args();
        // Each object
        foreach($objects as &$object) $this->with($object);
        // Garbage collection
        unset($object);

        // Return $this instance
        return $this;
    }

    /**
     * With, used to merge a singluar object
     *
     * Used to add an object to the composition
     *
     * @param object $object an object to merge
     * @return object the instance to enable linking
     */
    public function & with(&$object) {
        // An object
        if(is_object($object)) {
            // Reference
            if($this->use_reference) {
                if($this->first_precedence) array_push($this->composite, $object);
                else array_unshift($this->composite, $object);
            }
            // Clone
            else {
                if($this->first_precedence) array_push($this->composite, clone $object);
                else array_unshift($this->composite, clone $object);
            }
        }

        // Return $this instance
        return $this;
    }

    /**
     * __get, retrieves the psudo merged object
     *
     * @param string $name name of the variable in the object
     * @return mixed returns a reference to the requested variable
     *
     */
    public function & __get($name) {
        $return = NULL;
        foreach($this->composite as &$object) {
            if(isset($object->$name)) {
                $return =& $object->$name;
                break;
            }
        }
        // Garbage collection
        unset($object);

        return $return;
    }
}

Usage:

$obj = new Compositor(use_reference, first_precedence);
$obj->merge([object $object [, object $object [, object $...]]]);
$obj->with([object $object]);

Example:

$obj1 = new stdClass();
$obj1->a = 'obj1:a';
$obj1->b = 'obj1:b';
$obj1->c = 'obj1:c';

$obj2 = new stdClass();
$obj2->a = 'obj2:a';
$obj2->b = 'obj2:b';
$obj2->d = 'obj2:d';

$obj3 = new Compositor();
$obj3->merge($obj1, $obj2);
$obj1->c = '#obj1:c';
var_dump($obj3->a, $obj3->b, $obj3->c, $obj3->d);
// obj2:a, obj2:b, obj1:c, obj2:d
$obj1->c;

$obj3 = new Compositor(TRUE);
$obj3->merge($obj1)->with($obj2);
$obj1->c = '#obj1:c';
var_dump($obj3->a, $obj3->b, $obj3->c, $obj3->d);
// obj1:a, obj1:b, obj1:c, obj2:d
$obj1->c = 'obj1:c';

$obj3 = new Compositor(FALSE, TRUE);
$obj3->with($obj1)->with($obj2);
$obj1->c = '#obj1:c';
var_dump($obj3->a, $obj3->b, $obj3->c, $obj3->d);
// obj1:a, obj1:b, #obj1:c, obj2:d
$obj1->c = 'obj1:c';

Tags: advanced php → best coding → novice coding → solution

The best method to merge PHP objects

By Game Changer → Wednesday, December 9, 2015

Call PHP function from string stored in a Variable

Do you need call a dynamic function?

Defined in your script.. Need Calling Dynamically?

Use call_user_func() instead:

//for normal function 
call_user_func($myVar);
// if hello() is in the current namespace
call_user_func(__NAMESPACE__.'\\'.$myVar);

// if hello() is in another namespace
call_user_func('mynamespace\\'.$myVar);

Dynamic function names and namespaces

Just to add a point about dynamic function names when using namespaces.

If you're using namespaces, the following won't work except if your function is in the global namespace:

namespace greetings;
function hello()
{
    // do something
}

$myvar = "hello";
$myvar(); // interpreted as "\hello();"

Dynamic Writing?

Following code can help to write dynamic function in PHP. now the function name can be dynamically change by variable '$current_page'.

$current_page = 'home_page';
$function = @${$current_page . '_page_versions'};
$function = function() {
    echo 'current page';
};
$function();

Tags: advanced php → best coding → solution

Call PHP function from string stored in a Variable

By Game Changer → Sunday, December 6, 2015