Chris@18: <?php
Chris@18: 
Chris@18: namespace Drupal\Component\Version;
Chris@18: 
Chris@18: /**
Chris@18:  * A value object representing a Drupal version constraint.
Chris@18:  */
Chris@18: class Constraint {
Chris@18: 
Chris@18:   /**
Chris@18:    * The constraint represented as a string. For example '>=8.x-5.x'.
Chris@18:    *
Chris@18:    * @var string
Chris@18:    */
Chris@18:   protected $constraint;
Chris@18: 
Chris@18:   /**
Chris@18:    * A list of associative arrays representing the constraint.
Chris@18:    *
Chris@18:    * Each containing the keys:
Chris@18:    *  - 'op': can be one of: '=', '==', '!=', '<>', '<', '<=', '>', or '>='.
Chris@18:    *  - 'version': A complete version, e.g. '4.5-beta3'.
Chris@18:    *
Chris@18:    * @var array[]
Chris@18:    */
Chris@18:   protected $constraintArray = [];
Chris@18: 
Chris@18:   /**
Chris@18:    * Constraint constructor.
Chris@18:    *
Chris@18:    * @param string $constraint
Chris@18:    *   The constraint string to create the object from. For example, '>8.x-1.1'.
Chris@18:    * @param string $core_compatibility
Chris@18:    *   Core compatibility declared for the current version of Drupal core.
Chris@18:    *   Normally this is set to \Drupal::CORE_COMPATIBILITY by the caller.
Chris@18:    */
Chris@18:   public function __construct($constraint, $core_compatibility) {
Chris@18:     $this->constraint = $constraint;
Chris@18:     $this->parseConstraint($constraint, $core_compatibility);
Chris@18:   }
Chris@18: 
Chris@18:   /**
Chris@18:    * Gets the constraint as a string.
Chris@18:    *
Chris@18:    * Can be used in the UI for reporting incompatibilities.
Chris@18:    *
Chris@18:    * @return string
Chris@18:    *   The constraint as a string.
Chris@18:    */
Chris@18:   public function __toString() {
Chris@18:     return $this->constraint;
Chris@18:   }
Chris@18: 
Chris@18:   /**
Chris@18:    * A list of associative arrays representing the constraint.
Chris@18:    *
Chris@18:    * Each containing the keys:
Chris@18:    *  - 'op': can be one of: '=', '==', '!=', '<>', '<', '<=', '>', or '>='.
Chris@18:    *  - 'version': A complete version, e.g. '4.5-beta3'.
Chris@18:    *
Chris@18:    * @return array[]
Chris@18:    *   The constraint represented as an array.
Chris@18:    *
Chris@18:    * @deprecated in Drupal 8.7.0, will be removed before Drupal 9.0.0.
Chris@18:    *   Only exists to provide a backwards compatibility layer.
Chris@18:    *
Chris@18:    * @see https://www.drupal.org/node/2756875
Chris@18:    */
Chris@18:   public function toArray() {
Chris@18:     @trigger_error(sprintf('%s() only exists to provide a backwards compatibility layer. See https://www.drupal.org/node/2756875', __METHOD__), E_USER_DEPRECATED);
Chris@18:     return $this->constraintArray;
Chris@18:   }
Chris@18: 
Chris@18:   /**
Chris@18:    * Determines if the provided version is satisfied by this constraint.
Chris@18:    *
Chris@18:    * @param string $version
Chris@18:    *   The version to check, for example '4.2'.
Chris@18:    *
Chris@18:    * @return bool
Chris@18:    *   TRUE if the provided version is satisfied by this constraint, FALSE if
Chris@18:    *   not.
Chris@18:    */
Chris@18:   public function isCompatible($version) {
Chris@18:     foreach ($this->constraintArray as $constraint) {
Chris@18:       if (!version_compare($version, $constraint['version'], $constraint['op'])) {
Chris@18:         return FALSE;
Chris@18:       }
Chris@18:     }
Chris@18:     return TRUE;
Chris@18:   }
Chris@18: 
Chris@18:   /**
Chris@18:    * Parses a constraint string.
Chris@18:    *
Chris@18:    * @param string $constraint_string
Chris@18:    *   The constraint string to parse.
Chris@18:    * @param string $core_compatibility
Chris@18:    *   Core compatibility declared for the current version of Drupal core.
Chris@18:    *   Normally this is set to \Drupal::CORE_COMPATIBILITY by the caller.
Chris@18:    */
Chris@18:   private function parseConstraint($constraint_string, $core_compatibility) {
Chris@18:     // We use named subpatterns and support every op that version_compare
Chris@18:     // supports. Also, op is optional and defaults to equals.
Chris@18:     $p_op = '(?<operation>!=|==|=|<|<=|>|>=|<>)?';
Chris@18:     // Core version is always optional: 8.x-2.x and 2.x is treated the same.
Chris@18:     $p_core = '(?:' . preg_quote($core_compatibility) . '-)?';
Chris@18:     $p_major = '(?<major>\d+)';
Chris@18:     // By setting the minor version to x, branches can be matched.
Chris@18:     $p_minor = '(?<minor>(?:\d+|x)(?:-[A-Za-z]+\d+)?)';
Chris@18:     foreach (explode(',', $constraint_string) as $constraint) {
Chris@18:       if (preg_match("/^\s*$p_op\s*$p_core$p_major\.$p_minor/", $constraint, $matches)) {
Chris@18:         $op = !empty($matches['operation']) ? $matches['operation'] : '=';
Chris@18:         if ($matches['minor'] == 'x') {
Chris@18:           // Drupal considers "2.x" to mean any version that begins with
Chris@18:           // "2" (e.g. 2.0, 2.9 are all "2.x"). PHP's version_compare(),
Chris@18:           // on the other hand, treats "x" as a string; so to
Chris@18:           // version_compare(), "2.x" is considered less than 2.0. This
Chris@18:           // means that >=2.x and <2.x are handled by version_compare()
Chris@18:           // as we need, but > and <= are not.
Chris@18:           if ($op == '>' || $op == '<=') {
Chris@18:             $matches['major']++;
Chris@18:           }
Chris@18:           // Equivalence can be checked by adding two restrictions.
Chris@18:           if ($op == '=' || $op == '==') {
Chris@18:             $this->constraintArray[] = ['op' => '<', 'version' => ($matches['major'] + 1) . '.x'];
Chris@18:             $op = '>=';
Chris@18:           }
Chris@18:         }
Chris@18:         $this->constraintArray[] = ['op' => $op, 'version' => $matches['major'] . '.' . $matches['minor']];
Chris@18:       }
Chris@18:     }
Chris@18:   }
Chris@18: 
Chris@18: }