Add civimix-schema with SchemaHelper and AutomaticUpgrader

mixin/lib/civimix-schema/pathload.main.php

@@ -0,0 +1,28 @@
+<?php
+namespace CiviMix\Schema;
+
+\pathload()->activatePackage('civimix-schema@5', __DIR__, [
+  'reloadable' => TRUE,
+  // The civimix-schema library specifically supports installation processes. From a
+  // bootstrap/service-availability POV, this is a rough environment which leads to
+  // the "Multi-Activation Issue" and "Multi-Download Issue". To adapt to them,
+  // civimix-schema follows "Reloadable Library" patterns.
+  // More information: https://github.com/totten/pathload-poc/blob/master/doc/issues.md
+]);
+
+// When reloading, we make newer instance of the Facade object.
+$GLOBALS['CiviMixSchema5'] = require __DIR__ . '/src/CiviMixSchema5.php';
+
+if (!interface_exists(__NAMESPACE__ . '\SchemaHelperInterface')) {
+  require __DIR__ . '/src/SchemaHelperInterface.php';
+}
+
+// \CiviMix\Schema\loadClass() is a facade. The facade should remain identical across versions.
+if (!function_exists(__NAMESPACE__ . '\loadClass')) {
+
+  function loadClass(string $class) {
+    return $GLOBALS['CiviMixSchema5']->loadClass($class);
+  }
+
+  spl_autoload_register(__NAMESPACE__ . '\loadClass');
+}

mixin/lib/civimix-schema/src/AutomaticUpgrader.php

@@ -0,0 +1,135 @@
+<?php
+
+namespace CiviMix\Schema;
+
+/**
+ * The "AutomaticUpgrader" will create and destroy the SQL tables
+ * using XML schema files (`SchemaHelper`). It also calls-out to any custom
+ * upgrade code (eg `CRM_Myext_Upgrader`).
+ *
+ * To simplify backport considerations, `AutomaticUpgrader` does not have formal name.
+ * It is accessed via aliases like "CiviMix\Schema\*\AutomaticUpgrader".
+ *
+ * Target: CiviCRM v5.38+
+ */
+return new class() implements \CRM_Extension_Upgrader_Interface {
+
+  use \CRM_Extension_Upgrader_IdentityTrait {
+
+    init as initIdentity;
+
+  }
+
+  /**
+   * Optionally delegate to "CRM_Myext_Upgrader" or "Civi\Myext\Upgrader".
+   *
+   * @var \CRM_Extension_Upgrader_Interface|null
+   */
+  private $customUpgrader;
+
+  public function init(array $params) {
+    $this->initIdentity($params);
+    if ($info = $this->getInfo()) {
+      if ($class = $this->getDelegateUpgraderClass($info)) {
+        $this->customUpgrader = new $class();
+        $this->customUpgrader->init($params);
+        if ($errors = $this->checkDelegateCompatibility($this->customUpgrader)) {
+          throw new \CRM_Core_Exception("AutomaticUpgrader is not compatible with $class:\n" . implode("\n", $errors));
+        }
+      }
+    }
+  }
+
+  public function notify(string $event, array $params = []) {
+    $info = $this->getInfo();
+    if (!$info) {
+      return;
+    }
+
+    if ($event === 'install') {
+      $GLOBALS['CiviMixSchema5']->getHelper($this->getExtensionKey())->install();
+    }
+
+    if ($this->customUpgrader) {
+      $this->customUpgrader->notify($event, $params);
+    }
+
+    if ($event === 'uninstall') {
+      $GLOBALS['CiviMixSchema5']->getHelper($this->getExtensionKey())->uninstall();
+    }
+  }
+
+  /**
+   * Civix-based extensions have a conventional name for their upgrader class ("CRM_Myext_Upgrader"
+   * or "Civi\Myext\Upgrader"). Figure out if this class exists.
+   *
+   * @param \CRM_Extension_Info $info
+   * @return string|null
+   *   Ex: 'CRM_Myext_Upgrader' or 'Civi\Myext\Upgrader'
+   */
+  public function getDelegateUpgraderClass(\CRM_Extension_Info $info): ?string {
+    $candidates = [];
+
+    if (!empty($info->civix['namespace'])) {
+      $namespace = $info->civix['namespace'];
+      $candidates[] = sprintf('%s_Upgrader', str_replace('/', '_', $namespace));
+      $candidates[] = sprintf('%s\\Upgrader', str_replace('/', '\\', $namespace));
+    }
+
+    foreach ($candidates as $candidate) {
+      if (class_exists($candidate)) {
+        return $candidate;
+      }
+    }
+
+    return NULL;
+  }
+
+  public function getInfo(): ?\CRM_Extension_Info {
+    try {
+      return \CRM_Extension_System::singleton()->getMapper()->keyToInfo($this->extensionName);
+    }
+    catch (\CRM_Extension_Exception_ParseException $e) {
+      \Civi::log()->error("Parse error in extension " . $this->extensionName . ": " . $e->getMessage());
+      return NULL;
+    }
+  }
+
+  /**
+   * @param \CRM_Extension_Upgrader_Interface $upgrader
+   * @return array
+   *   List of error messages.
+   */
+  public function checkDelegateCompatibility($upgrader): array {
+    $class = get_class($upgrader);
+
+    $errors = [];
+
+    if (!($upgrader instanceof \CRM_Extension_Upgrader_Base)) {
+      $errors[] = "$class is not based on CRM_Extension_Upgrader_Base.";
+      return $errors;
+    }
+
+    // In the future, we will probably modify AutomaticUpgrader to build its own
+    // sequence of revisions (based on other sources of data). AutomaticUpgrader
+    // is only regarded as compatible with classes that strictly follow the standard revision-model.
+    $methodNames = [
+      'appendTask',
+      'onUpgrade',
+      'getRevisions',
+      'getCurrentRevision',
+      'setCurrentRevision',
+      'enqueuePendingRevisions',
+      'hasPendingRevisions',
+    ];
+    foreach ($methodNames as $methodName) {
+      $method = new \ReflectionMethod($upgrader, $methodName);
+      if ($method->getDeclaringClass()->getName() !== 'CRM_Extension_Upgrader_Base') {
+        $errors[] = "To ensure future interoperability, AutomaticUpgrader only supports {$class}::{$methodName}()  if it's inherited from CRM_Extension_Upgrader_Base";
+      }
+    }
+
+    return $errors;
+  }
+
+};

mixin/lib/civimix-schema/src/CiviMixSchema5.php

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+<?php
+namespace CiviMix\Schema;
+
+/**
+ * This object is known as $GLOBALS['CiviMixSchema5']. It is a reloadable service-object.
+ * (It may be reloaded if you enable a new extension that includes an upgraded copy.)
+ */
+return new class() {
+
+  /**
+   * @var string
+   *   Regular expression. Note the 2 groupings. $m[1] identifies a per-extension namespace. $m[2] identifies the actual class.
+   */
+  private $regex = ';^CiviMix\\\Schema\\\(\w+)\\\(AutomaticUpgrader)$;';
+
+  /**
+   * If someone requests a class like:
+   *
+   *    CiviMix\Schema\MyExt\AutomaticUpgrader
+   *
+   * then load the latest version of:
+   *
+   *    civimix-schema/src/Helper.php
+   */
+  public function loadClass(string $class) {
+    if (preg_match($this->regex, $class, $m)) {
+      $absPath = __DIR__ . DIRECTORY_SEPARATOR . $m[2] . '.php';
+      class_alias(get_class(require $absPath), $class);
+    }
+  }
+
+  /**
+   * @param string $extensionKey
+   *   Ex: 'org.civicrm.flexmailer'
+   * @return \CiviMix\Schema\SchemaHelperInterface
+   */
+  public function getHelper(string $extensionKey) {
+    $store = &\Civi::$statics['CiviMixSchema5-helpers'];
+    if (!isset($store[$extensionKey])) {
+      $class = get_class(require __DIR__ . '/SchemaHelper.php');
+      $store[$extensionKey] = new $class($extensionKey);
+    }
+    return $store[$extensionKey];
+  }
+
+};