civicrm.php

    // Load core CSS.
    if (!CRM_Core_BAO_Setting::getItem(CRM_Core_BAO_Setting::SYSTEM_PREFERENCES_NAME, 'disable_core_css')) {

      // Enqueue stylesheet.
      wp_enqueue_style(
        'civicrm_css',
        $config->resourceBase . 'css/civicrm.css',
        // Dependencies.
        NULL,
        // Version.
        CIVICRM_PLUGIN_VERSION,
        // Media.
        'all'
      );

      // Custom CSS is dependent.
      $dependent = ['civicrm_css'];

    }

    // Load custom CSS.
    if (!empty($config->customCSSURL)) {
      wp_enqueue_style(
        'civicrm_custom_css',
        $config->customCSSURL,
        // Dependencies.
        $dependent,
        // Version.
        CIVICRM_PLUGIN_VERSION,
        // Media.
        'all'
      );
    }

    // Set flag so this only happens once.
    $frontend_css_loaded = TRUE;

  }

  /**
   * Add CiviCRM core resources.
   *
   * @since 4.6
   *
   * @param bool $front_end True if on WordPress front end, false otherwise.
   */
  public function add_core_resources($front_end = TRUE) {

    if (!$this->initialize()) {
      return;
    }

    $config = CRM_Core_Config::singleton();
    $config->userFrameworkFrontend = $front_end;

    // Add CiviCRM core resources.
    CRM_Core_Resources::singleton()->addCoreResources();

  }

  /**
   * Merge CiviCRM's HTML header with the WordPress theme's header.
   *
   * Callback from WordPress 'admin_head' and 'wp_head' hooks.
   *
   * @since 4.4
   */
  public function wp_head() {

    if (!$this->initialize()) {
      return;
    }

    /*
     * CRM-11823
     * If CiviCRM bootstrapped, then merge its HTML header with the CMS's header.
     */
    global $civicrm_root;
    if (empty($civicrm_root)) {
      return;
    }

    $region = CRM_Core_Region::instance('html-header', FALSE);
    if ($region) {
      echo '<!-- CiviCRM html header -->';
      echo $region->render('');
    }

  }

  // ---------------------------------------------------------------------------
  // CiviCRM Invocation (this outputs CiviCRM's markup)
  // ---------------------------------------------------------------------------

  /**
   * Invoke CiviCRM in a WordPress context.
   *
   * Callback function from add_menu_page()
   * Callback from WordPress 'init' and 'the_content' hooks
   * Also called by shortcode_render() and _civicrm_update_user()
   *
   * @since 4.4
   */
  public function invoke() {

    static $alreadyInvoked = FALSE;
    if ($alreadyInvoked) {
      return;
    }

    // Bail if this is called via a content-preprocessing plugin.
    if ($this->is_page_request() && !in_the_loop() && !is_admin()) {
      return;
    }

    if (!$this->initialize()) {
      return;
    }

    /*
     * CRM-12523
     * WordPress has it's own timezone calculations. CiviCRM relies on the PHP
     * default timezone which WordPress overrides with UTC in wp-settings.php
     */
    $wpBaseTimezone = date_default_timezone_get();
    $wpUserTimezone = get_option('timezone_string');
    if ($wpUserTimezone) {
      date_default_timezone_set($wpUserTimezone);
      CRM_Core_Config::singleton()->userSystem->setMySQLTimeZone();
    }

    /*
     * CRM-95XX
     * At this point we are in a CiviCRM context. WordPress always quotes the
     * request, so CiviCRM needs to reverse what it just did.
     */
    $this->remove_wp_magic_quotes();

    // Required for AJAX calls.
    if ($this->civicrm_in_wordpress()) {
      $_REQUEST['noheader'] = $_GET['noheader'] = TRUE;
    }

    // Code inside invoke() requires the current user to be set up.
    $current_user = wp_get_current_user();

    /*
     * Bypass synchronize if running upgrade to avoid any serious non-recoverable
     * error which might hinder the upgrade process.
     */
    if (CRM_Utils_Array::value('q', $_GET) != 'civicrm/upgrade') {
      $this->users->sync_user($current_user);
    }

    // Set flag.
    $alreadyInvoked = TRUE;

    // Get args.
    $argdata = $this->get_request_args();

    // Set dashboard as default if args are empty.
    if (empty($argdata['argString'])) {
      $_GET['q'] = 'civicrm/dashboard';
      $_GET['reset'] = 1;
      $argdata['args'] = ['civicrm', 'dashboard'];
    }

    // Do the business.
    CRM_Core_Invoke::invoke($argdata['args']);

    // Restore WordPress's timezone.
    if ($wpBaseTimezone) {
      date_default_timezone_set($wpBaseTimezone);
    }

    // Restore WordPress's arrays.
    $this->restore_wp_magic_quotes();

    /**
     * Broadcast that CiviCRM has been invoked.
     *
     * @since 4.4
     */
    do_action('civicrm_invoked');

  }

  /**
   * Non-destructively override WordPress magic quotes.
   *
   * Only called by invoke() to undo WordPress default behaviour.
   *
   * @since 4.4
   * @since 5.7 Rewritten to work with query vars.
   */
  private function remove_wp_magic_quotes() {

    // Save original arrays.
    $this->wp_get     = $_GET;
    $this->wp_post    = $_POST;
    $this->wp_cookie  = $_COOKIE;
    $this->wp_request = $_REQUEST;

    // Reassign globals.
    $_GET     = stripslashes_deep($_GET);
    $_POST    = stripslashes_deep($_POST);
    $_COOKIE  = stripslashes_deep($_COOKIE);
    $_REQUEST = stripslashes_deep($_REQUEST);

    // Test for query var.
    $q = get_query_var('q');
    if (!empty($q)) {

      $page = get_query_var('civiwp');
      $reset = get_query_var('reset');
      $id = get_query_var('id');
      $html = get_query_var('html');
      $snippet = get_query_var('snippet');

      $action = get_query_var('action');
      $mode = get_query_var('mode');
      $cid = get_query_var('cid');
      $gid = get_query_var('gid');
      $sid = get_query_var('sid');
      $cs = get_query_var('cs');
      $force = get_query_var('force');

      $_REQUEST['q'] = $_GET['q'] = $q;
      $_REQUEST['civiwp'] = $_GET['civiwp'] = 'CiviCRM';
      if (!empty($reset)) {
        $_REQUEST['reset'] = $_GET['reset'] = $reset;
      }
      if (!empty($id)) {
        $_REQUEST['id'] = $_GET['id'] = $id;
      }
      if (!empty($html)) {
        $_REQUEST['html'] = $_GET['html'] = $html;
      }
      if (!empty($snippet)) {
        $_REQUEST['snippet'] = $_GET['snippet'] = $snippet;
      }

      if (!empty($action)) {
        $_REQUEST['action'] = $_GET['action'] = $action;
      }
      if (!empty($mode)) {
        $_REQUEST['mode'] = $_GET['mode'] = $mode;
      }
      if (!empty($cid)) {
        $_REQUEST['cid'] = $_GET['cid'] = $cid;
      }
      if (!empty($gid)) {
        $_REQUEST['gid'] = $_GET['gid'] = $gid;
      }
      if (!empty($sid)) {
        $_REQUEST['sid'] = $_GET['sid'] = $sid;
      }
      if (!empty($cs)) {
        $_REQUEST['cs'] = $_GET['cs'] = $cs;
      }
      if (!empty($force)) {
        $_REQUEST['force'] = $_GET['force'] = $force;
      }

      /**
       * Broadcast that CiviCRM query vars have been assigned.
       *
       * Use in combination with `civicrm_query_vars` filter to ensure that any
       * other query vars are included in the assignment to the super-global
       * arrays.
       *
       * @since 5.7
       */
      do_action('civicrm_query_vars_assigned');

    }

  }

  /**
   * Restore WordPress magic quotes.
   *
   * Only called by invoke() to redo WordPress default behaviour.
   *
   * @since 4.4
   */
  private function restore_wp_magic_quotes() {

    // Restore original arrays.
    $_GET     = $this->wp_get;
    $_POST    = $this->wp_post;
    $_COOKIE  = $this->wp_cookie;
    $_REQUEST = $this->wp_request;

  }

  /**
   * Detect Ajax, snippet, or file requests.
   *
   * @since 4.4
   *
   * @return boolean True if request is for a CiviCRM page, false otherwise.
   */
  public function is_page_request() {

    // Assume not a CiviCRM page.
    $return = FALSE;

    // Kick out if not CiviCRM.
    if (!$this->initialize()) {
      return $return;
    }

    // Get args.
    $argdata = $this->get_request_args();

    // Grab query var.
    $html = get_query_var('html');
    if (empty($html)) {
      $html = isset($_GET['html']) ? $_GET['html'] : '';
    }

    /*
     * FIXME: It's not sustainable to hardcode a whitelist of all of non-HTML
     * pages. Maybe the menu-XML should include some metadata to make this
     * unnecessary?
     */
    if (CRM_Utils_Array::value('HTTP_X_REQUESTED_WITH', $_SERVER) == 'XMLHttpRequest'
        || ($argdata['args'][0] == 'civicrm' && in_array($argdata['args'][1], ['ajax', 'file']))
        || !empty($_REQUEST['snippet'])
        || strpos($argdata['argString'], 'civicrm/event/ical') === 0 && empty($html)
        || strpos($argdata['argString'], 'civicrm/contact/imagefile') === 0
    ) {
      $return = FALSE;
    }
    else {
      $return = TRUE;
    }

    return $return;

  }

  /**
   * Get arguments and request string from query vars.
   *
   * @since 4.6
   *
   * @return array $argdata Array containing request arguments and request string.
   */
  public function get_request_args() {

    $argString = NULL;
    $args = [];

    // Get path from query vars.
    $q = get_query_var('q');
    if (empty($q)) {
      $q = isset($_GET['q']) ? $_GET['q'] : '';
    }

    /*
     * Fix 'civicrm/civicrm' elements derived from CRM:url()
     * @see https://lab.civicrm.org/dev/rc/issues/5#note_16205
     */
    if (defined('CIVICRM_CLEANURL') && CIVICRM_CLEANURL) {
      if (substr($q, 0, 16) === 'civicrm/civicrm/') {
        $q = str_replace('civicrm/civicrm/', 'civicrm/', $q);
        $_REQUEST['q'] = $_GET['q'] = $q;
        set_query_var('q', $q);
      }
    }

    if (!empty($q)) {
      $argString = trim($q);
      // Remove / from the beginning and ending of query string.
      $argString = trim($argString, '/');
      $args = explode('/', $argString);
    }
    $args = array_pad($args, 2, '');

    return [
      'args' => $args,
      'argString' => $argString,
    ];

  }

  /**
   * Get base URL.
   *
   * Clone of CRM_Utils_System_WordPress::getBaseUrl() whose access is set to
   * private. Until it is public, we cannot access the URL of the basepage since
   * CRM_Utils_System_WordPress::url().
   *
   * 27-09-2016
   * CRM-16421 CRM-17633 WIP Changes to support WordPress in it's own directory.
   * https://wiki.civicrm.org/confluence/display/CRM/WordPress+installed+in+its+own+directory+issues
   * For now leave hard coded wp-admin references.
   * TODO: remove wp-admin references and replace with admin_url() in the future.
   * TODO: Look at best way to get path to admin_url.
   *
   * @since 4.4
   *
   * @param bool $absolute Passing TRUE prepends the scheme and domain, FALSE doesn't.
   * @param bool $frontend Passing FALSE returns the admin URL.
   * @param $forceBackend Passing TRUE overrides $frontend and returns the admin URL.
   * @return mixed|null|string
   */
  public function get_base_url($absolute, $frontend, $forceBackend) {
    $config = CRM_Core_Config::singleton();
    if ((is_admin() && !$frontend) || $forceBackend) {
      return Civi::paths()->getUrl('[wp.backend]/.', $absolute ? 'absolute' : 'relative');
    }
    else {
      return Civi::paths()->getUrl('[wp.frontend]/.', $absolute ? 'absolute' : 'relative');
    }
  }

}

/*
 * -----------------------------------------------------------------------------
 * Procedures start here
 * -----------------------------------------------------------------------------
 */

/**
 * The main function responsible for returning the CiviCRM_For_WordPress instance
 * to functions everywhere.
 *
 * Use this function like you would a global variable, except without needing to
 * declare the global.
 *
 * Example: $civi = civi_wp();
 *
 * @since 4.4
 *
 * @return CiviCRM_For_WordPress The plugin instance.
 */
function civi_wp() {
  return CiviCRM_For_WordPress::singleton();
}

/*
 * Instantiate CiviCRM_For_WordPress immediately.
 *
 * @see CiviCRM_For_WordPress::setup_instance()
 */
civi_wp();

/*
 * Tell WordPress to call plugin activation method - no longer calls legacy
 * global scope function.
 */
register_activation_hook(CIVICRM_PLUGIN_FILE, [civi_wp(), 'activate']);

/*
 * Tell WordPress to call plugin deactivation method - needed in order to reset
 * the option that is set on activation.
 */
register_deactivation_hook(CIVICRM_PLUGIN_FILE, [civi_wp(), 'deactivate']);

/*
 * Uninstall uses the 'uninstall.php' method.
 *
 * @see https://developer.wordpress.org/reference/functions/register_uninstall_hook/
 */

// Include legacy global scope functions.
include_once CIVICRM_PLUGIN_DIR . 'includes/civicrm.functions.php';

/**
 * Incorporate WP-CLI Integration.
 *
 * Based on drush CiviCRM functionality, work done by Andy Walker.
 * https://github.com/andy-walker/wp-cli-civicrm
 *
 * @since 4.5
 */
if (defined('WP_CLI') && WP_CLI) {
  // Changed from __DIR__ because of possible symlink issues.
  include_once CIVICRM_PLUGIN_DIR . 'wp-cli/civicrm.php';
}