/modules/civicrm/CRM/Extension/Info.php

<?php
/*
 +--------------------------------------------------------------------+
 | Copyright CiviCRM LLC. All rights reserved.                        |
 |                                                                    |
 | This work is published under the GNU AGPLv3 license with some      |
 | permitted exceptions and without any warranty. For full license    |
 | and copyright information, see https://civicrm.org/licensing       |
 +--------------------------------------------------------------------+
 */

/**
 * Metadata for an extension (e.g. the extension's "info.xml" file)
 *
 * @package CRM
 * @copyright CiviCRM LLC https://civicrm.org/licensing
 */
class CRM_Extension_Info {

  /**
   * Extension info file name.
   */
  const FILENAME = 'info.xml';

  /**
   * @var string
   */
  public $key = NULL;
  public $type = NULL;
  public $name = NULL;
  public $label = NULL;
  public $file = NULL;

  /**
   * @var array
   *   Each item is a specification like:
   *   array('type'=>'psr4', 'namespace'=>'Foo\Bar', 'path'=>'/foo/bar').
   */
  public $classloader = [];

  /**
   * @var array
   *   Each item is they key-name of an extension required by this extension.
   */
  public $requires = [];

  /**
   * @var array
   *   List of expected mixins.
   *   Ex: ['civix@2.0.0']
   */
  public $mixins = [];

  /**
   * @var array
   *   List of strings (tag-names).
   */
  public $tags = [];

  /**
   * @var array
   *   List of authors.
   *   Ex: [0 => ['name' => 'Alice', 'email' => 'a@b', 'homepage' => 'https://example.com', 'role' => 'Person']]
   */
  public $authors = [];

  /**
   * @var array|null
   *   The current maintainer at time of publication.
   *   This is deprecated in favor of $authors.
   * @deprecated
   */
  public $maintainer = NULL;

  /**
   * @var string|null
   *  The name of a class which handles the install/upgrade lifecycle.
   * @see \CRM_Extension_Upgrader_Interface
   */
  public $upgrader = NULL;

  /**
   * Load extension info an XML file.
   *
   * @param $file
   *
   * @throws CRM_Extension_Exception_ParseException
   * @return CRM_Extension_Info
   */
  public static function loadFromFile($file) {
    list ($xml, $error) = CRM_Utils_XML::parseFile($file);
    if ($xml === FALSE) {
      throw new CRM_Extension_Exception_ParseException("Failed to parse info XML: $error");
    }

    $instance = new CRM_Extension_Info();
    $instance->parse($xml);
    return $instance;
  }

  /**
   * Load extension info a string.
   *
   * @param string $string
   *   XML content.
   *
   * @throws CRM_Extension_Exception_ParseException
   * @return CRM_Extension_Info
   */
  public static function loadFromString($string) {
    list ($xml, $error) = CRM_Utils_XML::parseString($string);
    if ($xml === FALSE) {
      throw new CRM_Extension_Exception_ParseException("Failed to parse info XML: $string");
    }

    $instance = new CRM_Extension_Info();
    $instance->parse($xml);
    return $instance;
  }

  /**
   * Build a reverse-dependency map.
   *
   * @param array $infos
   *   The universe of available extensions.
   *   Ex: $infos['org.civicrm.foobar'] = new CRM_Extension_Info().
   * @return array
   *   If "org.civicrm.api" is required by "org.civicrm.foo", then return
   *   array('org.civicrm.api' => array(CRM_Extension_Info[org.civicrm.foo])).
   *   Array(string $key => array $requiredBys).
   */
  public static function buildReverseMap($infos) {
    $revMap = [];
    foreach ($infos as $info) {
      foreach ($info->requires as $key) {
        $revMap[$key][] = $info;
      }
    }
    return $revMap;
  }

  /**
   * @param null $key
   * @param null $type
   * @param null $name
   * @param null $label
   * @param null $file
   */
  public function __construct($key = NULL, $type = NULL, $name = NULL, $label = NULL, $file = NULL) {
    $this->key = $key;
    $this->type = $type;
    $this->name = $name;
    $this->label = $label;
    $this->file = $file;
  }

  /**
   * Copy attributes from an XML document to $this
   *
   * @param SimpleXMLElement $info
   */
  public function parse($info) {
    $this->key = (string) $info->attributes()->key;
    $this->type = (string) $info->attributes()->type;
    $this->file = (string) $info->file;
    $this->label = (string) $info->name;
    $this->upgrader = (string) $info->upgrader;

    // Convert first level variables to CRM_Core_Extension properties
    // and deeper into arrays. An exception for URLS section, since
    // we want them in special format.
    foreach ($info as $attr => $val) {
      if (count($val->children()) == 0) {
        $this->$attr = trim((string) $val);
      }
      elseif ($attr === 'urls') {
        $this->urls = [];
        foreach ($val->url as $url) {
          $urlAttr = (string) $url->attributes()->desc;
          $this->urls[$urlAttr] = (string) $url;
        }
        ksort($this->urls);
      }
      elseif ($attr === 'classloader') {
        $this->classloader = [];
        foreach ($val->psr4 as $psr4) {
          $this->classloader[] = [
            'type' => 'psr4',
            'prefix' => (string) $psr4->attributes()->prefix,
            'path' => (string) $psr4->attributes()->path,
          ];
        }
        foreach ($val->psr0 as $psr0) {
          $this->classloader[] = [
            'type' => 'psr0',
            'prefix' => (string) $psr0->attributes()->prefix,
            'path' => (string) $psr0->attributes()->path,
          ];
        }
      }
      elseif ($attr === 'tags') {
        $this->tags = [];
        foreach ($val->tag as $tag) {
          $this->tags[] = (string) $tag;
        }
      }
      elseif ($attr === 'mixins') {
        $this->mixins = [];
        foreach ($val->mixin as $mixin) {
          $this->mixins[] = (string) $mixin;
        }
      }
      elseif ($attr === 'requires') {
        $this->requires = $this->filterRequirements($val);
      }
      elseif ($attr === 'maintainer') {
        $this->maintainer = CRM_Utils_XML::xmlObjToArray($val);
        $this->authors[] = [
          'name' => (string) $val->author,
          'email' => (string) $val->email,
          'role' => 'Maintainer',
        ];
      }
      elseif ($attr === 'authors') {
        foreach ($val->author as $author) {
          $this->authors[] = $thisAuthor = CRM_Utils_XML::xmlObjToArray($author);
          if ('maintainer' === strtolower($thisAuthor['role'] ?? '')) {
            $this->maintainer = ['author' => $thisAuthor['name'], 'email' => $thisAuthor['email'] ?? NULL];
          }
        }
      }
      else {
        $this->$attr = CRM_Utils_XML::xmlObjToArray($val);
      }
    }
  }

  /**
   * Filter out invalid requirements, e.g. extensions that have been moved to core.
   *
   * @param SimpleXMLElement $requirements
   * @return array
   */
  public function filterRequirements($requirements) {
    $filtered = [];
    $compatInfo = CRM_Extension_System::getCompatibilityInfo();
    foreach ($requirements->ext as $ext) {
      $ext = (string) $ext;
      if (empty($compatInfo[$ext]['obsolete'])) {
        $filtered[] = $ext;
      }
    }
    return $filtered;
  }

}