Add system check to ensure WP base page exists

CRM/Utils/Check/Component/Cms.php

@@ -0,0 +1,160 @@
+<?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       |
+ +--------------------------------------------------------------------+
+ */
+
+/**
+ *
+ * @package CRM
+ * @copyright CiviCRM LLC https://civicrm.org/licensing
+ */
+class CRM_Utils_Check_Component_Cms extends CRM_Utils_Check_Component {
+
+  /**
+   * For sites running in WordPress, make sure the configured base page exists.
+   *
+   * @return array
+   *   Instances of CRM_Utils_Check_Message
+   */
+  public static function checkWpBasePage() {
+    $config = CRM_Core_Config::singleton();
+    if ($config->userFramework != 'WordPress') {
+      return [];
+    }
+    if (is_multisite()) {
+      // There are a lot potential configurations in a multisite context where
+      // this could show a false positive.  This completely skips multisite for
+      // now.
+      return [];
+    }
+
+    switch (self::pageExists($config->wpBasePage)) {
+      case 1:
+        // Page is here and published
+        return [];
+
+      case 0:
+        $messageText = [
+          ts(
+            'CiviCRM relies upon a <a href="%1%2">base page in WordPress</a>, but it is not published.',
+            [
+              1 => $config->userFrameworkBaseURL,
+              2 => $config->wpBasePage,
+            ]
+          ),
+        ];
+        break;
+
+      case -1:
+        // Page is missing, but let's look around to see if the default is there
+        // --either the default as modified by civicrm_basepage_slug or the
+        // default default, `civicrm`.
+        $cmsSettings = CRM_Utils_System::url(
+          'civicrm/admin/setting',
+          $query = ['reset' => 1],
+          FALSE,
+          NULL,
+          TRUE,
+          FALSE,
+          TRUE
+        );
+        $messageText = [
+          ts(
+            'CiviCRM relies upon a base page in WordPress at %1%2, but it is missing.',
+            [
+              1 => $config->userFrameworkBaseURL,
+              2 => $config->wpBasePage,
+            ]
+          ),
+        ];
+
+        $altSlugs = array_unique([
+          apply_filters('civicrm_basepage_slug', 'civicrm'),
+          'civicrm',
+        ]);
+
+        if (in_array($config->wpBasePage, $altSlugs)) {
+          $messageText[] = ts(
+            'If you have an alternative base page, it can be set in the <a href="%2">WordPress integration settings</a>.',
+            [
+              1 => $config->userFrameworkBaseURL,
+              2 => $cmsSettings,
+            ]
+          );
+        }
+        else {
+          foreach ($altSlugs as $slug) {
+            $exists = self::pageExists($slug);
+            if ($exists >= 0) {
+              // One of the possible defaults is here, published or not.
+              $messageText[] = ts(
+                'The default is %1%2, which <a href="%1%2">does exist on this site</a>.',
+                [
+                  1 => $config->userFrameworkBaseURL,
+                  2 => $slug,
+                ]
+              );
+              if ($exists == 0) {
+                $messageText[] = ts('However, it is not published.');
+              }
+              // We've found one, and if the `civicrm_basepage_slug` filter has
+              // modified the default, we should go with it.
+              break;
+            }
+          }
+          if ($exists == -1) {
+            // We went through the default(s) and couldn't find one.  Defer to
+            // the one modified by the filter.
+            $messageText[] = ts(
+              'The default is %1%2, but that does not exist on this site either.',
+              [
+                1 => $config->userFrameworkBaseURL,
+                2 => $altSlugs[0],
+              ]
+            );
+          }
+
+          $messageText[] = ts(
+            'You can set the correct base page in the <a href="%1">WordPress integration settings</a>.',
+            [1 => $cmsSettings]
+          );
+        }
+    }
+
+    return [
+      new CRM_Utils_Check_Message(
+        __FUNCTION__,
+        implode(' ', $messageText),
+        ts('WordPress Base Page Missing'),
+        \Psr\Log\LogLevel::ERROR,
+        'fa-wordpress'
+      ),
+    ];
+  }
+
+  /**
+   * See if a page exists and is published.
+   *
+   * @param string $slug
+   *   The page path.
+   * @return int
+   *   -1 if it's missing
+   *   0 if it's present but not published
+   *   1 if it's present and published
+   */
+  private static function pageExists($slug) {
+    $basePage = get_page_by_path($slug);
+    if (!$basePage) {
+      return -1;
+    }
+
+    return (int) ($basePage->post_status == 'publish');
+  }
+
+}