PHP functions and variable scope in Smarty

Question

I'm working within Smarty 2.6.27. There is something that prevents PHP functions from accessing global variables:

{php}
  $a = "should be global";

  function test(){
    global $a;
    echo $a;
  }
  test();
{/php}

But the variable $a never makes it into the function. I've also done this:

{php}
  $a = "should be global";

  foreach ($GLOBALS as $key => $value) { 
     echo $key . "-" . $value;
  } 
{/php}

But again, $a does not make it into the list of PHP globals. It seems that this is because Smarty runs PHP in some odd context--for example, the documentation mentions this:

To access PHP variables in {php} blocks you will need to use the PHP global keyword.

I don't really need to get access to other PHP globals, and I don't particularly want the scope of variables created here to go wider, I simply need to figure out how to use variables defined outside of the functions in the function. There will be a lot of these variables, so passing them as parameters is impractical.

Answer 1

Firstly, for the record I strongly recommend avoiding both {php} blocks in Smarty, and global variables. Try to find some other solution to the underlying problem.

That out of the way, you quote this line from the manual, but you haven't followed its advice:

To access PHP variables in {php} blocks you will need to use the PHP global keyword.

What it means is this:

{php}
  global $a;
  $a = "should be global";
{/php}

Without that, the variable $a is scoped to whatever function context the generated code is run in. There is no special consideration for "nested" functions or scopes in PHP, so a variable is either global, or visible only inside that one function.