Fatal error: Using $this when not in object context using array_walk

Question

I have made a class that should replace data at the hand of an array.

I insert

$data = array(
                'bike',
                'car',
                'pc'
            );

And it should translate the array to :

$data = array(
                '[@bike]',
                '[@car]',
                '[@pc]'
            );

I have written the following piece of code.

array_walk($PlaceHolders , function(&$value, $key) { $value = $this->Seperators['plcstart'].$value.$this->Seperators['plcend']; });

Which I am using in a class context.

The two sperators have the following value:

$this->Seperators['plcstart'] = '[@';
$this->Seperators['plcend']   = ']';

The problem is. At localhost it works superb!! Now when I upload the system to a unix environment it stops working! I have no clue why this is the result.

Would anyone here know what I am doing wrong?

Start by considering the different versions of PHP that are running on your development/localhost environment and on your production environment.... and consider why they are different when they shouldn't be — Mark Baker
– Mark Baker, Commented Nov 27, 2014 at 18:47
array_walk won't invoke your object, the function you're defining as the callback won't be a method of your object either. it's just a plain regular function, and $this won't be available. — Marc B
– Marc B, Commented Nov 27, 2014 at 18:48
Where and how are the values of $this->Seperators defined? Is all this defined within a class method? — Mark Baker
– Mark Baker, Commented Nov 27, 2014 at 18:59
The $this->Seperators are defined within the class. I think it might be a good idea to set the Seperators in a loose variable. $Start = $this->Seperators['plcstart']; etc.. — Alex
– Alex, Commented Nov 27, 2014 at 19:27

Falc · Accepted Answer · 2014-11-27 19:38:22Z

1

I would recommend you to use array_map() when you want to modify array elements using a callback.

You could end with something like this

class TransformerClass {
    private $Seperators = array(
        'plcstart' => '[@',
        'plcend' => ']'
    );

    public function transform(array $data) {
        return array_map(
            function($text) {
                return $this->Seperators['plcstart'].$text.$this->Seperators['plcend'];
            },
            $data
        );
    }
}

Example:

$transformer = new TransformerClass();

$items = array(
    'bike',
    'car',
    'pc'
);

$result = $transformer->transform($items);

And $result will contain your desired resulting data.

answered Nov 27, 2014 at 19:38

Falc

5951 gold badge5 silver badges15 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Alex · Accepted Answer · 2014-11-28 09:34:24Z

The most bizare thing is... This morning I opened the same page again. And it worked like the offline environment :-S....

This is quite frustrating though!!

However I would like to make a few small notes:

  ///######## LOADING ALL PLACEHOLDERS
  $PlaceHolders   = array_keys($this->TplObjects);

  ///######## SEPERATOR START
  $SeperatorStart = $this->Seperators['plcstart'];
  $SeperatorEnd   = $this->Seperators['plcend'];

  ///######## ADDING THE START AND END TAGS TO EACH ARRAY VALUE
  array_walk($PlaceHolders , function(&$value, $key) { $value =
  $SeperatorStart.$value.$SeperatorEnd; });

This is what I thought to be a solution but it is NOT!! Why?? Because the way it was worked:

    ///######## LOADING ALL PLACEHOLDERS
    $PlaceHolders = array_keys($this->TplObjects);
    ///######## ADDING THE START AND END TAGS TO EACH ARRAY VALUE
    array_walk($PlaceHolders , function(&$value, $key) { $value = $this->Seperators['plcstart'].$value.$this->Seperators['plcend']; });

Because it got it's data directly out of the class. By using function I placed the variables into it's own individual scope, hence the variable $SeperatorStart and $SeperatorEnd do not exist in this scope.

I could ofcourse import these two into that function. But I do not know how to do this with array_walk. I have not used this function this often hence I know only a few basic manners to use this function.

The second option as opted for above by @Falc works great! And is the method I was looking for. Hence thanks a million!!

Collectives™ on Stack Overflow

Fatal error: Using $this when not in object context using array_walk

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related