Question

I have the following function in the php script,

public function createPorductstatushistory($item) {

    $stmt = mysqli_prepare($this->connection, "INSERT INTO $this->tablename (timeStamp, ProductDetail_idProduct, ProductStatus_idStatus) VALUES (?, ?, ?)");
    $this->throwExceptionOnError();

    mysqli_stmt_bind_param
    ($stmt, 'sii', 
    $item->timeStamp->toString('YYYY-MM-dd HH:mm:ss'), 
    $item->ProductDetail_idProduct, 
    $item->ProductStatus_idStatus);
    $this->throwExceptionOnError();

    mysqli_stmt_execute($stmt);     
    $this->throwExceptionOnError();

    $autoid = mysqli_stmt_insert_id($stmt);

    mysqli_stmt_free_result($stmt);     
    mysqli_close($this->connection);

    return $autoid;
}

but, everytime I go to the part “$item->timeStamp->toString(‘YYYY-MM-dd HH:mm:ss’)”. The following error pop up.

There was an error while invoking the operation. Check your operation
inputs or server code and try invoking the operation again.

Reason: Notice: Trying to get property of non-object in
C:\xampp\htdocs\fypweee_admin\FYPadminSideV3-debug\services\PorductstatushistoryService.php
on line 125

Fatal error: Call to a member function toString() on a non-object in
C:\xampp\htdocs\fypweee_admin\FYPadminSideV3-debug\services\PorductstatushistoryService.php
on line 125

Is this mean the timeStamp var need to be in format of ‘YYYY-MM-dd HH:mm:ss’?

Answer 1

Your $item object has a property timeStamp. You assume that the timeStamp property of $item is an object. But the error tells you that timeStamp is not an object.

This could mean that you never set an instance of an object to timeStamp.

Example:

class TimeStamp
{
    time = '13:00';
}

class Item
{
    public $timeStamp;
}

$item = new Item();
$item->timeStamp->time;

This would result in such an error. You need to initialize TimeStamp and assign that to your $timeStamp variable.

class TimeStamp
{
    time = '13:00';
}

class Item
{
    public $timeStamp;

    public Item()
    {
        $this->$timeStamp = new TimeStamp();
    }
}

$item = new Item();
$item->timeStamp->time;

Now this should work, because TimeStamp is initialized in the constructor and assigned to the $timeStamp variable.

So please recheck your code and make sure everything you need is instantiated