From fd8790d5cf7d65a0ecc51355a5a3dc985213d8a2 Mon Sep 17 00:00:00 2001
From: Simey Lameze <simey@moodle.com>
Date: Fri, 2 Jun 2017 11:19:42 +0800
Subject: [PATCH] MDL-59008 repository_googledocs: add method to serve login on
 a popup

This commit also add a new string logintoaccount to make the login
button more clear.
---
 lang/en/repository.php        |  1 +
 repository/googledocs/lib.php | 36 ++++++++++++++++++++++++++++++++++-
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/lang/en/repository.php b/lang/en/repository.php
index 1a89457bfbb..53825f5c098 100644
--- a/lang/en/repository.php
+++ b/lang/en/repository.php
@@ -155,6 +155,7 @@ $string['linkexternal'] = 'Link external';
 $string['listview'] = 'View as list';
 $string['loading'] = 'Loading...';
 $string['login'] = 'Login to your account';
+$string['logintoaccount'] = 'Login to your {$a} account';
 $string['logout'] = 'Logout';
 $string['lostsource'] = 'Error. Source is missing. {$a}';
 $string['makefileinternal'] = 'Make a copy of the file';
diff --git a/repository/googledocs/lib.php b/repository/googledocs/lib.php
index 0c340e833e7..401c71d56f6 100644
--- a/repository/googledocs/lib.php
+++ b/repository/googledocs/lib.php
@@ -131,6 +131,33 @@ class repository_googledocs extends repository {
         }
     }
 
+    /**
+     * Print the login in a popup.
+     *
+     * @param array|null $attr Custom attributes to be applied to popup div.
+     */
+    public function print_login_popup($attr = null) {
+        global $OUTPUT, $PAGE;
+
+        $client = $this->get_user_oauth_client(false);
+        $url = new moodle_url($client->get_login_url());
+        $state = $url->get_param('state') . '&reloadparent=true';
+        $url->param('state', $state);
+
+        $PAGE->set_pagelayout('embedded');
+        echo $OUTPUT->header();
+
+        $repositoryname = get_string('pluginname', 'repository_googledocs');
+
+        $button = new single_button($url, get_string('logintoaccount', 'repository', $repositoryname), 'post', true);
+        $button->add_action(new popup_action('click', $url, 'Login'));
+        $button->class = 'mdl-align';
+        $button = $OUTPUT->render($button);
+        echo html_writer::div($button, '', $attr);
+
+        echo $OUTPUT->footer();
+    }
+
     /**
      * Build the breadcrumb from a path.
      *
@@ -613,8 +640,15 @@ class repository_googledocs extends repository {
                                                    $storedfile->get_filename(),
                                                    $forcedownload);
             $url->param('sesskey', sesskey());
-            $userauth = $this->get_user_oauth_client($url);
+            $param = ($options['embed'] == true) ? false : $url;
+            $userauth = $this->get_user_oauth_client($param);
             if (!$userauth->is_logged_in()) {
+                if ($options['embed'] == true) {
+                    // Due to Same-origin policy, we cannot redirect to googledocs login page.
+                    // If the requested file is embed and the user is not logged in, add option to log in using a popup.
+                    $this->print_login_popup(['style' => 'margin-top: 250px']);
+                    exit;
+                }
                 redirect($userauth->get_login_url());
             }
             if ($userauth === false) {