Converts a list of possible parameters into a stack of permutations.

Takes a list of parameters containing possible values, and converts all of them into a list of items containing every possible permutation.

Example:

$parameters = array(
  'one' => array(0, 1),
  'two' => array(2, 3),
);
$permutations = DrupalTestCase::generatePermutations($parameters)
// Result:
$permutations == array(
  array('one' => 0, 'two' => 2),
  array('one' => 1, 'two' => 2),
  array('one' => 0, 'two' => 3),
  array('one' => 1, 'two' => 3),
)

Parameters

$parameters: An associative array of parameters, keyed by parameter name, and whose values are arrays of parameter values.

Return value

A list of permutations, which is an array of arrays. Each inner array contains the full list of parameters that have been passed, but with a single value only.

File

drupal-7.x/modules/simpletest/drupal_web_test_case.php, line 664

Class

DrupalTestCase

Base class for Drupal tests.

Code

public static function generatePermutations($parameters) {
  $all_permutations = array(array());
  foreach ($parameters as $parameter => $values) {
    $new_permutations = array();
    // Iterate over all values of the parameter.
    foreach ($values as $value) {
      // Iterate over all existing permutations.
      foreach ($all_permutations as $permutation) {
        // Add the new parameter value to existing permutations.
        $new_permutations[] = $permutation + array($parameter => $value);
      }
    }
    // Replace the old permutations with the new permutations.
    $all_permutations = $new_permutations;
  }
  return $all_permutations;
}