How to read this expression/what does it mean?

PHP
1

Hi folks,
am new to php and i was going through code error and i had error on a line which says

 $row = $this->_data[0];

i don’t know how to read this or what is that and what is going on here. can anyone explain what is this?

2

I thought of that too and while i waited for your reply i was putting if statement with isset as gvre said (thanks gvre) and the logic which came into my mind was same as u mentioned that user might have not filled the fields.
Thanks for the help guys ! :slight_smile:

3

Interesting function that one. It does


		if (isset($this->_data[0]))

        $row = $this->_data[0];

but doesnt give an else… so it’s expecting data to have been returned by the buildQuery and getList…

buildQuery on pay_info should query out

SELECT * FROM #__br_user WHERE user_id=" . $this->_user_id

(Not sure what #__br_user means in this context, but it seems to be a Joomla templating fixer)

Only thing i can think of at this point is check your database to see if said table has any data for that user?

4

and which function are you calling that generates this error?

5 
 getPayInfo()

where variables are assigned to $row

6

To what i can comprehend is that if user doesn’t have any info like data information this error pop up.?

7

here is text file of that php file

8

EDIT: or better, is there somewhere we can find this class you’re using?

9

so it doesnt fill in the data at all… unless it’s parent class does

is there an add data function?

10

here in the construct function


    function __construct() {
        parent::__construct();
        global $mainframe, $option;
        $user = & JFactory::getUser();
        $this->_myuser = & $user;
        $this->_user_id = $user->id;

        //echo "<br>".$user->name;exit;
    }
11

What does the constructor function define _data with?

12

as i am newbie so don’t know about classes n constructor. what i understand from what ur saying is to look for a function __construct(found that) in which data has been defined or called?

13

Without seeing the class definition of the object in question, it will be hard to answer your question, but;

Check the Constructor of the class (function __construct) to see if it puts any data into _data[0] by default.

If so, we’ll need to see the whole class cause something’s going wrong. (Stop here.)
If not, check to see if there’s a method to add a row of data to the object. (Continue below)

If not, you’ve got a very bad class.
If so, you’ll need to add data to the object before trying to call whatever method you’re describing above.

14

code itself is very long, However i can post few line which jump error to next one.


        if (isset($this->_data[0]))
{
        $row = $this->_data[0]; 
}
        //
        //$row = $this->_data[0];
         $id = $row->id;
         $user_id = $row->user_id;
          $name = $row->name;
          $subscriptionId = $row->subscriptionId;
          $customerPaymentProfileId = $row->customerPaymentProfileId;

thats the code,How do i know if $row is set or not.to check its value b4 it get to these lines?

15

My wild guess is that maybe its a local variable and not global? if so how can i see what’s going on and if its local or global? any string or array function i can use?

16

Could you post the source code?

17

“What does it mean”.

The line reads as:

Assign to $row the value of this object’s _data array (the _ at the start indicates that this element is considered “Private” to the object), pulling from the first element of the array.

Based on it being assigned to something called $row, i’m assuming _data[0] is itself an array.

18

That helped, but the error moves on to the next $row and so on. how do i track this bug so that if $row doesn’t exist it doesn’t show at all. more important how do i get to read the my posted query in plain English

19

I suppose that _data[0] does no exist. You should check if _data array has members.
eg

if (isset($this->_data[0]))
        $row = $this->_data[0];