Passing class to other scripts

[Dooley]

Hey I was just wondering, is it technically possible to pass a class between php scripts, if not is it possible to pass an array of data, at the moment im using hidden variables and loops with post to do it, but there must be a better way.

Thanks in advance

[NogDog]

You can save an instantiated object as a session variable. If you do this, it is necessary that you load the class definition before you do the session_start() that loads the session data.

You can also use [man]serialize/man to store an object in a database or file. Again, you need to be sure in subsequent scripts to load the class definition before you load and [man]unserialize[/man] the object.

[jeff_tet]

Can't you just use the global keyword?

global $myclass;

The class will have to be initiated before you can call global.

[Dooley]

Well the script im calling is itself. So I don't think global will work.

Basically the user enters data that passes to a object, and I wanna pass the object to the script itself.

[NogDog]

jeff.tet wrote:

Can't you just use the global keyword?

global $myclass;

The class will have to be initiated before you can call global.

global will just make that variable accessible from within the function where it appears. It has nothing to do with passing objects between scripts, though (unless I'm misunderstanding the problem).

[Dooley]

Okay so should this work?

In the script when creating an object.
$Totalans = new answerClass($aquestion,$index,$survey);
$_SESSION['previousans$in']=$Totalans;

And then this to get it back.
$obj = new answerClass(NULL,NULL,NULL);
$answer=$_SESSION['previousans$index'];

[Dooley]

Ok I gave this a go and I serialized the object and passed it through.
I have a loop that passes will create an object each time and create and pass into a session variable name ans$loop.

However when I try get the answer out it always gets the last answer.

Here's some code.

$Totalans = new answerClass($aquestion,$index,$survey);
$Totalans->display();
$s=serialize($Totalans);
$string=$in."previousans";
unset($SESSION['$string']);
$SESSION['$string']=$s;
$in++;

$string=$in."previousans";
$s=$_SESSION['$string'];
$obj=unserialize($s);
$obj->display();

Always displays the second answer.... hope someone can help!

Thanks again for all your help

[Dooley]

Another solution I was thinking of is an array of objects, but again I don't know how to implement this.

I've tried creating a objects pushing them onto an array serializing the array the passing it into a session variable then unserialising it but the array elements don't seem to want to be objects....

[Dooley]

Anyone??

[NogDog]

You should not need to do any serializing if saving to a session variable, as the serializing is done automatically in that case.
For a basic example:

<?php
// a simple demo class:
class Test
{
   private $var = 0;
   public function __construct($init = null)
   {
      if($init !== null)
      {
         $this->var = $init;
      }
   }
   public function setVar($val)
   {
      $this->var = $val;
   }
   public function getVar()
   {
      return $this->var;
   }
}
// alwasy start session after all class definitions are included/defined
session_start();
// use object from session if it's there:
if(isset($_SESSION['test']))
{
   $obj = $_SESSION['test'];
   $obj->setVar($obj->getVar() + 1);
}
else  // else instantiate a new object:
{
   $obj = new Test(1);
}
// show the object:
echo "<pre>";
print_r($obj);  // $val should increment by one on each reload of page
echo "</pre>\n";
// save object to session data:
$_SESSION['test'] = $obj;
?>

Note that you could even automate the saving of the object to the session via a __destruct() method (assuming you're using PHP5).

[Dooley]

Hey Nog Dog, because there is an awful lot of inputs/outputs in my class is there a way to do what your saying without the get/set methods. Ie

$obj = $_SESSION['test'];
print_r($obj)

[Dooley]

Okay for some weird reason say I have 2 session variable set name 1 and 2.

Everytime I try get both 1 and 2 I always only get 2!

Very frustrating!!!

[NogDog]

Dooley wrote:

Okay for some weird reason say I have 2 session variable set name 1 and 2.

Everytime I try get both 1 and 2 I always only get 2!

Very frustrating!!!

Afraid I don't understand: perhaps a bit more explanation along with some code would help? (Providing the shortest, simplest code that reproduces the problem would help.)

[Dooley]

Okay here we go

//When the script is called how I set the session objects
for($in=0;$in!=3;$in++){
$Totalans = new answerClass($aquestion,$index,$survey);
$Totalans->display();
$s=serialize($Totalans);
$string=$in;
$SESSION['$string']=$s;
$in++;
}
//And for when we get the objects
for($in=0;$in!=3;$in++){
$string=$in;
$s=$SESSION['$string'];
$obj=unserialize($s);
$obj->display();
}

[NogDog]

<?php
//When the script is called how I set the session objects
for($in=0;$in!=3;$in++){
   $Totalans = new answerClass($aquestion,$index,$survey);
   $Totalans->display();
   $_SESSION[$in]=$Totalans;
}
//And for when we get the objects
for($in=0;$in!=3;$in++){
   $obj=$_SESSION[$in];
   $obj->display();
}
?>

[NogDog]

Or even simpler:

<?php
//When the script is called how I set the session objects
for($in=0;$in!=3;$in++){
   $_SESSON[$in] = new answerClass($aquestion,$index,$survey);
   $_SESSION[$in]->display();
}
//And for when we get the objects
for($in=0;$in!=3;$in++){
   $_SESSION[$in]->display();
}
?>

[Dooley]

So im trying this, its all in one script.
This at the bottom of my script and sets all the values

for($in=0;$in!=3;$in++){
unset($SESSION[$in]);
$SESSION[$in] = new answerClass($aquestion,$index,$survey);
$SESSION[$in]->display();

}
And at the top I always check if the value is set, it never is....
for($in=0;$in!=3;$in++){
if(isset($SESSION[$in])){
echo "It is set";
$SESSION[$in]->display();
$SESSION[$in]->answertomysql();
}
}
At the very very top I start the session and include the class.
<?php
include("answer.class.php");
session_start();
?>

Can anyone see any potential problems??
Thanks again for the help.

[Dooley]

Weird I even tried setting session variables that were non-objects in the very same way.
No luck...

[Dooley]

Okay solved the last problem.
Instead of this
$SESSION[$in]->display();
Use this
$SESSION['$in']->display();

Right so I'm just going to show what my initial problem is. This is a simple example, I don't know if the session variable are being overwritten or what.

Here's how I set a few session variables...
for($ind=5;$ind!=9;$ind++){
$string="test string $ind";
$SESSION['$ind']=$string;
$s=$SESSION['$ind'];
print "False session value being set is $s";

        }

Which prints out..
False session value being set is test string 5, at index 5
False session value being set is test string 6, at index 6
False session value being set is test string 7, at index 7
False session value being set is test string 8, at index 8
Which is grand.

Then when I try display the list of session variables.

for($ind=5;$ind!=9;$ind++){
$string= $_SESSION['$ind'];
print "<br />Getting fake session value $string at index $ind<br />";
}

Its gets this....
Getting fake session value test string 8 at index 5

Getting fake session value test string 8 at index 6

Getting fake session value test string 8 at index 7

Getting fake session value test string 8 at index 8

Its like the last session variable is overwriting all of them?
This exact same thing is happening with my objects... Has anyone come across this?

[NogDog]

$SESSION['$ind'] does not use the value of the variable $ind as the index to the $SESSION array; instead it uses the literal string '$ind' as the index. This is because variables are not interpolated within single-quoted strings, only within double-quoted strings (or "heredoc" quoted strings). In any case, there is no reason to quote the variable in that context, since you just need the value of $ind without any other string literal characters.

for($ind=5;$ind!=9;$ind++){
   $string="test string $ind";
   $_SESSION[$ind]=$string;
   $s=$_SESSION[$ind];
   print "False session value being set is $s";
}