mnet MDL-21278 print a list of potential idps on the login page with links

this adds a new contract auth plugin method (implemented as empty in the base class)

auth/mnet/auth.php

@@ -1240,5 +1240,42 @@ class auth_plugin_mnet extends auth_plugin_base {
         return $logline;
     }
 
-
+    /**
+     * Returns a list of potential IdPs that this authentication plugin supports.
+     * This is used to provide links on the login page.
+     *
+     * @param string $wantsurl the relative url fragment the user wants to get to.  You can use this to compose a returnurl, for example
+     *
+     * @return array like:
+     *              array(
+     *                  array(
+     *                      'url' => 'http://someurl',
+     *                      'icon' => new pix_icon(...),
+     *                      'name' => get_string('somename', 'auth_yourplugin'),
+     *                 ),
+     *             )
+     */
+    function loginpage_idp_list($wantsurl) {
+        global $DB, $CFG;
+        // strip off wwwroot, since the remote site will prefix it's return url with this
+        $wantsurl = preg_replace('/(' . preg_quote($CFG->wwwroot, '/') . '|' . preg_quote($CFG->httpswwwroot, '/') . ')/', '', $wantsurl);
+        if (!$hosts = $DB->get_records_sql('SELECT DISTINCT h.*, a.sso_jump_url,a.name as application
+                FROM {mnet_host} h
+                JOIN {mnet_host2service} m ON h.id=m.hostid
+                JOIN {mnet_service} s ON s.id=m.serviceid
+                JOIN {mnet_application} a ON h.applicationid = a.id
+                WHERE s.name=? AND h.deleted=? AND m.publish = ?',
+                array('sso_sp', 0, 1))) {
+            return array();
+        }
+        $idps = array();
+        foreach ($hosts as $host) {
+            $idps[] = array(
+                'url'  => new moodle_url($host->wwwroot . $host->sso_jump_url, array('hostwwwroot' => $CFG->wwwroot, 'wantsurl' => $wantsurl, 'remoteurl' => 1)),
+                'icon' => new pix_icon('i/' . $host->application . '_host', $host->name),
+                'name' => $host->name,
+            );
+        }
+        return $idps;
+    }
 }

lang/en_utf8/auth.php

@@ -391,6 +391,7 @@ $string['auto_add_remote_users'] = 'Auto add remote users';
 $string['ntlmsso_attempting'] = 'Attempting Single Sign On via NTLM...';
 $string['ntlmsso_failed'] = 'Auto-login failed, try the normal login page...';
 $string['ntlmsso_isdisabled'] = 'NTLM SSO is disabled.';
+$string['potentialidps'] = 'Do you usually log in somewhere else before arriving here?<br />Choose from the following list to log in at your usual place:';
 $string['rpc_negotiation_timeout'] = 'RPC negotiation timeout';
 $string['shib_no_attributes_error'] = 'You seem to be Shibboleth authenticated but Moodle didn\'t receive any user attributes. Please check that your Identity Provider releases the necessary attributes ($a) to the Service Provider Moodle is running on or inform the webmaster of this server.';
 $string['shib_not_all_attributes_error'] = 'Moodle needs certain Shibboleth attributes which are not present in your case. The attributes are: $a<br />Please contact the webmaster of this server or your Identity Provider.';

lib/authlib.php

@@ -440,5 +440,23 @@ class auth_plugin_base {
         return false;
     }
 
+    /**
+     * Returns a list of potential IdPs that this authentication plugin supports.
+     * This is used to provide links on the login page.
+     *
+     * @param string $wantsurl the relative url fragment the user wants to get to.  You can use this to compose a returnurl, for example
+     *
+     * @return array like:
+     *              array(
+     *                  array(
+     *                      'url' => 'http://someurl',
+     *                      'icon' => new pix_icon(...),
+     *                      'name' => get_string('somename', 'auth_yourplugin'),
+     *                 ),
+     *             )
+     */
+    function loginpage_idp_list($wantsurl) {
+        return array();
+    }
 
 }

login/index.php

@@ -234,19 +234,6 @@ if (empty($CFG->usesid) and $testcookies and (get_moodle_cookie() == '')) {    /
             $errormsg = get_string("invalidlogin");
             $errorcode = 3;
         }
-
-        if ( !empty($CFG->mnet_dispatcher_mode)
-             && $CFG->mnet_dispatcher_mode === 'strict'
-             && is_enabled_auth('mnet')
-             && $DB->record_exists_sql('SELECT h.id FROM {mnet_host} h
-                INNER JOIN {mnet_host2service} m ON h.id=m.hostid
-                INNER JOIN {mnet_service} s ON s.id=m.serviceid
-                WHERE s.name=? AND h.deleted=? AND m.publish = ?',
-                array('sso_sp', 0, 1))
-            && $DB->record_exists_select('user', 'username = ? AND mnethostid != ?', array($frm->username, $CFG->mnet_localhost_id))
-        ) {
-            $errormsg .= get_string('loginlinkmnetuser', 'mnet', "mnet_email.php?u=$frm->username");
-        }
     }
 }
 
@@ -317,6 +304,12 @@ if (!empty($CFG->registerauth) or is_enabled_auth('none') or !empty($CFG->auth_i
     $show_instructions = false;
 }
 
+$potentialidps = array();
+foreach($authsequence as $authname) {
+    $authplugin = get_auth_plugin($authname);
+    $potentialidps = array_merge($potentialidps, $authplugin->loginpage_idp_list($SESSION->wantsurl));
+}
+
 $PAGE->set_title("$site->fullname: $loginsite");
 $PAGE->set_heading("$site->fullname");
 $PAGE->set_focuscontrol($focus);

login/index_form.html

@@ -91,4 +91,14 @@ if ($show_instructions) {
       </div>
     </div>
 <?php } ?>
+<?php if (!empty($potentialidps)) { ?>
+    <div class="subcontent potentialidps">
+        <h6><?php print_string('potentialidps', 'auth'); ?></h6>
+        <div class="potentialidplist">
+<?php foreach ($potentialidps as $idp) {
+    echo  '<div class="potentialidp"><a href="' . $idp['url']->out() . '" title="' . $idp['name'] . '">' . $OUTPUT->render($idp['icon'], $idp['name']) . '&nbsp;' . $idp['name'] . '</a></div>';
+} ?>
+        </div>
+    </div>
+<?php } ?>
 </div>

login/mnet_email.php

@@ -1,50 +0,0 @@
-<?php
-
-require_once dirname(dirname(__FILE__)) . '/config.php';
-httpsrequired();
-
-$username = required_param('u', PARAM_ALPHANUM);
-$sesskey = sesskey();
-
-// if you are logged in then you shouldn't be here
-if (isloggedin() and !isguestuser()) {
-    redirect( $CFG->wwwroot.'/', get_string('loginalready'), 5);
-}
-
-$PAGE->set_url('/login/mnet_email.php', array('u'=>$username));
-
-$mnetidprovider = get_string('mnetidprovider','mnet');
-$PAGE->navbar->add($mnetidprovider);
-$PAGE->set_title($mnetidprovider);
-$PAGE->set_heading($mnetidprovider);
-$PAGE->set_focuscontrol('email');
-
-echo $OUTPUT->header();
-echo $OUTPUT->notification(get_string('mnetidproviderdesc', 'mnet'));
-
-if ($form = data_submitted() and confirm_sesskey()) {
-    if ($user = $DB->get_record_select('user', 'username = ? AND email = ? AND mnethostid != ?', array($username,$form->email, $CFG->mnet_localhost_id))) {
-        if (!empty($user->mnethostid) and $host = $DB->get_record('mnet_host', array('id'=>$user->mnethostid))) {
-            $link = "<a href=\"{$host->wwwroot}/login/\">{$host->name}</a>";
-            notice(get_string('mnetidprovidermsg','mnet',$link));
-        }
-    }
-    if (empty($link)) {
-        notice(get_string('mnetidprovidernotfound', 'mnet'));
-    }
-}
-
-echo '<p>&nbsp;</p>';
-echo $OUTPUT->box_start('generalbox boxaligncenter boxwidthnormal');
-
-?>
-  <form method="post">
-    <input type="hidden" name="sesskey" value="<?php echo $sesskey; ?>">
-    <?php echo get_string('email') ?>:
-    <input type="text" name="email" id="email" size="" maxlength="100" />
-    <input type="submit" value="<?php echo get_string('findlogin','mnet'); ?>" />
-  </form>
-<?php
-
-echo $OUTPUT->box_end();
-echo $OUTPUT->footer();

theme/standardold/style/styles_layout.css

@@ -2944,13 +2944,23 @@ div.allcoursegrades {
 }
 
 .loginbox .guestsub,
-.loginbox .forgotsub {
+.loginbox .forgotsub,
+.loginbox .potentialidps {
   border-top:1px solid;
   margin-left:12%;
   margin-right:12%;
   margin-bottom:5px;
 }
 
+.loginbox .potentialidps .potentialidplist {
+    margin-left:40%;
+}
+
+.loginbox .potentialidps .potentialidplist div {
+  text-align:left;
+}
+
+
 .loginbox .loginform {
   margin-top:1em;
   text-align:left;