Contructor returns false but condition passed

[OhLordy]

Here is the code for the constructor

    function image($input_name)
    {
        echo("in here".$input_name);
        if(isset($HTTP_POST_FILES[$input_name]['name']))
        {
            echo("in here");
            $this->name =   $HTTP_POST_FILES[$input_name]['name'];
            $this->tmp  =   $HTTP_POST_FILES[$input_name]["tmp_name"];
            $this->size =   $HTTP_POST_FILES[$input_name]["size"];
            $this->type =   $HTTP_POST_FILES[$input_name]["type"];
            if($this->size>$MAXSIZE)
            {
                $this->error.="File is too large\n";
                return false;
            }
            elseif(substr($this->type,0,5)!="image")
            {
                $this->error.="File not an image\n";
                return false;
            }
            echo("name: ".$this->name."<br />\ntmp: ".$this->tmp."<br />\nsize: ".$this->size."<br />\ntype: ".$this->type);
            return true;
        }
        else
        {
            echo("false side<br />\n");
            $this->error.="No file uploaded\n";
            echo("right here<br />\n");
            return false;
        }
        return false;
    }
?>

and this is how I'm calling it

<?
if($img1=new image('test1'))
{
?>

The problem is, even though the function is failing the condition in the test script is still passing.

Thanks in advance
Rob

[adamgeorge]

I think there's a couple of problems with your script.

First when you write this:

<? 
if($img1=new image('test1')) 
{ 
?> 

what you are doing is testing whether the object $img1 exists.

Whether the constructor returns false or not, the object will still be created, so that statement will return true.

At least, that is my understanding anyway.

As well this section in the constructor doesn't look right:

if($this->size>$MAXSIZE) 
            { 
                $this->error.="File is too large\n"; 
                return false; 
            } 

What is $MAXSIZE? It is not defined anywhere in the function.

If it is a global variable you will need to reference it:

global $MAXSIZE

Hope that helps,
-Adam 🙂

[laserlight]

As far as I know, constructors may not return a value.

[OhLordy]

Yea I think you're right. I've got around it by making another function called checkError to check if any of the errors were triggered. It works but do you think this is OK or should all this stuff be outside of the constructor?

Cheers for your help
Rob

[ahundiak]

Just to confirm what laserlight said, constructors cannot return values. You will always get an object back (unless the script aborts).

And, as you said, you can either have the constructor set an error flag and check it afterwards or move the constructor code to an init method and have it return a status code. Either approach is perfectly acceptable.