[RESOLVED] PHP OOP - Storing Multiple Serialized Objects, Storing Serialized Objects in Text Fil

[digioz]

Hello Everyone,

I am trying to store several serialized PHP Objects in a text file and retrieve them later on. Here is the code I am using:

<?php

// Basic Test Class for the Object to be Serialized ---------------

class testClass
{
     var $attribute;
     var $attribute2;
     var $cB;
     function set_attribute($a,$b)
     {
     $this->attribute = $a;
     $this->attribute2 = $b;
     $this->cB = $a . ", oh beautiful " . $b;
     }
     function display()
     {
        echo $this->cB;
     }
}

// Creating a New Object and setting a and b values ---------------

$a = new testClass();
$a->set_attribute("Hello", "World");
$a->display();
echo "<br><br>";
echo serialize($a);

// saving Object to text file -----------------------------------------------

$fp = fopen("postData.txt","a");
$data = addslashes(serialize($a))."<!-- E -->";
fwrite($fp, $data);
fclose($fp);

// reloading from File and output to screen ----------------------------

if (file_exists("postData.txt")) {
$filename = "postData.txt";
$handle = fopen($filename, "r");
$datain = fread($handle, filesize($filename));
fclose($handle);
$out = explode("<!-- E -->", $datain);
$bla = unserialize($out[0]);
echo "<br><u>Retrieved Data</u><br>";
echo $bla->display();
}
?> 

However, I get the following error message:

Fatal error: Call to a member function on a non-object in c:\apache\htdocs\scripts\serialized_object_storage  _txt.php on line 49

Line 49 is basically the echo call:

echo $bla->display();

Does anyone know why I am getting this error message?

[Drakla]

Why are you adding slashes? And the best way is to create an array of the objects, use then serialise that array.

I ran your code by taking out the slashes and explode stuff and it works.

[halojoy]

the name of the object
you created with new
is

$a = new .... // creates an object, which should be used whenever call class function

maybe try this
$a->display();

also you shouldnt need to use 'echo'
as this is already performed in your class function 'display()'

I am refering to error in line 49

echo $bla->display();

you can get same result as
$a->display();

using:
$bla = $a->cB; // reads class variable into $bla
echo $bla;

.

[digioz]

Thank you Halojoy and Drakla

Here is how my final WORKING code looks like (in case someone else wants to use it):

  

<?php

// Basic Test Class for the Object to be Serialized ---------------

class testClass
{
     var $attribute;
     var $attribute2;
     var $cB;
     function set_attribute($a,$b)
     {
     $this->attribute = $a;
     $this->attribute2 = $b;
     $this->cB = $a . ", oh beautiful " . $b;
     }
     function display()
     {
        echo $this->cB;
     }
}

// Creating a New Object and setting a and b values ---------------

$a = new testClass();
$a->set_attribute("Hello", "World");
$a->display();
echo "<br><br>";
echo serialize($a);

// saving Object to text file -----------------------------------------------

$fp = fopen("postData.txt","a");
$data = serialize($a)."<!-- E -->";
fwrite($fp, $data);
fclose($fp);

// reloading from File and output to screen ----------------------------

if (file_exists("postData.txt")) {
$filename = "postData.txt";
$handle = fopen($filename, "r");
$datain = fread($handle, filesize($filename));
fclose($handle);
$out = explode("<!-- E -->", $datain);
$bla = unserialize($out[0]);

echo "<br><u>Retrieved Data</u><br>";
echo $bla->display();

echo "<br>";
$bla = unserialize($out[1]);
echo $bla->display();
}
?>

In case anyone is wondering WHY you would ever need this code, I am going to use this code to create the next version of my Guestbook Script (DigiOz Guestbook 1.7), storing entries into a text data file. By storing entries as objects, it will simplify the storage and retrieval of entries to the guestbook, and will also allow us to easily edit and or delete entries to it.

For more information, feel free to visit (Open Source Code):

http://www.digioz.com/phpscripts.php

[halojoy]

//$a = new class object
// some other code here
////////////////////////////////////////////

// reloading from File and output to screen ---------------------------- 

if (file_exists("postData.txt")) { 
$filename = "postData.txt"; 
$handle = fopen($filename, "r"); 
$datain = fread($handle, filesize($filename)); 
fclose($handle); 
$out = explode("<!-- E -->", $datain); 
$bla = unserialize($out[0]); 

echo "<br><u>Retrieved Data</u><br>"; 
echo $bla->display(); 

echo "<br>"; 
$bla = unserialize($out[1]); 
echo $bla->display(); 
}

I do not know why, but this code will give same errror as described in your first post.
To me it is same code.

So people, if no changes is made to bad functional code
do not try to use this script ( unless you change in a way similiar to my advice earlier in thread )

Because it is trying to use objects that wasnt created with 'new'.

Undefined Flying Object ( UFO )
in this case is: $bla

Hope this is some temporary 'miss-posting' by our dear topic starter.
I am sure it is!

Regards
halojoy - alias halojoy 'ET' from another planet

.