Using Static Variables in a Custom Module

Question

I'm trying to define a static variable for use in my custom module. I want it to let me pass a number from function to function. I'm using drupal_static() but I can't get it to work. How do I do this?

This is the code I'm using to define my static variable.

$var = &drupal_static(__FUNCTION__);
if (!isset($var)) {
  // generate contents of static variable
  $var = '8';
}
return $var;

I've tried putting it in a custom module.

 function viewusercontact_locateuser($value, $key, &$counter) {
   global $user;

   /**********In here***********/

   if ($value['uid'] == $user->uid) {
      ........
   }
}

I can't seem to get it to work. What am I doing wrong?

(I got my code from the following guides)

https://api.drupal.org/api/drupal/includes!bootstrap.inc/function/drupal_static/7 http://www.lullabot.com/blog/article/beginners-guide-caching-data-drupal-7 http://erikwebb.net/blog/drupal-design-patterns/static

Answer 1

drupal_static() stores variables based on the name of the function they're related to (hence the use of __FUNCTION__ when you initialise it in the relevant function).

You can pick it up again in any other function by querying drupal_static() again, with the name of the originating function. So in your case:

function viewusercontact_foo() {
  $static_var = drupal_static('viewusercontact_locateuser');
  ...
}

Answer 2

Here's a write up of my final solution.

I solved this problem by avoiding it completely. But the solution to the problem posted is below (as solved by Clive). First you have to define a static variable in a separate function:

function myvariable_function() {
  $var = &drupal_static(__FUNCTION__);
      if (!isset($var)) {
        // generate contents of static variable
        $var = '8';
      }
    return $var;
}

Then in the first place you use the variable you need it you have to call the function.

$var = myvariable_function();

From then on you can call it from other functions, by referencing the function.

function my_other_function () {
  $dom =  &drupal_static('myvariable_function');
}

In order to change that value in another function you can set:

$dom = $something_else;

And then when you call it again with &drupal_static, it will be updated:

$newvar = &drupal_static('myvariable_function');

Answer 3

You can't pass a static variable value from a function to another. The scope of a static variable is the function where it is declared. It keeps its value between all calls to same function in the same request.