diff -Naur assign/backup/moodle2/backup_assign_stepslib.php assign23/backup/moodle2/backup_assign_stepslib.php
--- assign/backup/moodle2/backup_assign_stepslib.php	2012-05-26 13:36:12.000000000 +0100
+++ assign23/backup/moodle2/backup_assign_stepslib.php	2012-06-25 21:42:18.000000000 +0100
@@ -74,7 +74,8 @@
                                                  'grader',
                                                  'grade',
                                                  'locked',
-                                                 'mailed'));
+                                                 'mailed',
+                                                 'extensionduedate'));
 
         $pluginconfigs = new backup_nested_element('plugin_configs');
 
diff -Naur assign/db/install.xml assign23/db/install.xml
--- assign/db/install.xml	2012-05-26 13:36:12.000000000 +0100
+++ assign23/db/install.xml	2012-06-25 18:59:37.000000000 +0100
@@ -56,7 +56,8 @@
         <FIELD NAME="grader" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" PREVIOUS="timemodified" NEXT="grade"/>
         <FIELD NAME="grade" TYPE="number" LENGTH="10" NOTNULL="false" DEFAULT="0" SEQUENCE="false" DECIMALS="5" COMMENT="The numerical grade for this assignment submission. Can be determined by scales/advancedgradingforms etc but will always be converted back to a floating point number." PREVIOUS="grader" NEXT="locked"/>
         <FIELD NAME="locked" TYPE="int" LENGTH="1" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="A flag to prevent changes for a single student submission." PREVIOUS="grade" NEXT="mailed"/>
-        <FIELD NAME="mailed" TYPE="int" LENGTH="1" NOTNULL="true" DEFAULT="0" SEQUENCE="false" PREVIOUS="locked"/>
+        <FIELD NAME="mailed" TYPE="int" LENGTH="1" NOTNULL="true" DEFAULT="0" SEQUENCE="false" PREVIOUS="locked" NEXT="extensionduedate"/>
+        <FIELD NAME="extensionduedate" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false" COMMENT="An optional submission extension date just for this student." PREVIOUS="mailed"/>
       </FIELDS>
       <KEYS>
         <KEY NAME="primary" TYPE="primary" FIELDS="id" COMMENT="The unique id for this grade." NEXT="assignment"/>
diff -Naur assign/extensionform.php assign23/extensionform.php
--- assign/extensionform.php	1970-01-01 00:00:00.000000000 +0000
+++ assign23/extensionform.php	2012-06-25 20:09:00.000000000 +0100
@@ -0,0 +1,95 @@
+<?php
+
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
+
+/**
+* This file contains the extension date form used by the assign module.
+*
+* @package mod_assign
+* @copyright 2012 NetSpot {@link http://www.netspot.com.au}
+* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+*/
+
+defined('MOODLE_INTERNAL') || die('Direct access to this script is forbidden.');
+
+
+/** Include locallib.php */
+require_once($CFG->libdir . '/formslib.php');
+require_once($CFG->dirroot . '/mod/assign/locallib.php');
+
+/**
+* Assignment extension form
+*
+* @package mod_assign
+* @copyright 2012 NetSpot {@link http://www.netspot.com.au}
+* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+*/
+class mod_assign_extension_form extends moodleform implements renderable {
+
+    /** @var assign $assignment The current instance of the assign class */
+    var $assignment;
+    /** @var stdClass $user The user who is being granted an extension */
+    var $user;
+
+    /**
+* Define this moodleform. Called by the parent constructor
+*/
+    function definition() {
+        $mform = $this->_form;
+
+        list($assignment, $user, $data) = $this->_customdata;
+        $this->assignment = $assignment;
+        $this->user = $user;
+
+        if ($this->assignment->get_instance()->allowsubmissionsfromdate) {
+            $mform->addElement('static', 'allowsubmissionsfromdate', get_string('allowsubmissionsfromdate', 'assign'), userdate($this->assignment->get_instance()->allowsubmissionsfromdate));
+        }
+        if ($this->assignment->get_instance()->duedate) {
+            $mform->addElement('static', 'duedate', get_string('duedate', 'assign'), userdate($this->assignment->get_instance()->duedate));
+        }
+        $mform->addElement('date_time_selector', 'extensionduedate', get_string('extensionduedate', 'assign'), array('optional'=>true));
+        $mform->setDefault('extensionduedate', NULL);
+        $mform->addElement('hidden', 'id', $assignment->get_course_module()->id);
+        $mform->addElement('hidden', 'userid', $user->id);
+        $mform->addElement('hidden', 'action', 'saveextension');
+        $this->add_action_buttons(true, get_string('savechanges', 'assign'));
+        if ($data) {
+            $this->set_data($data);
+        }
+    }
+
+    /**
+* Perform minimal validation on the extension form
+* @param array $data
+* @param array $files
+* @return array $errors - a list of validation errors keyed by the element name
+*/
+    function validation($data, $files) {
+        $errors = parent::validation($data, $files);
+        if ($this->assignment->get_instance()->duedate && $data['extensionduedate']) {
+            if ($this->assignment->get_instance()->duedate > $data['extensionduedate']) {
+                $errors['extensionduedate'] = get_string('extensionnotafterduedate', 'assign');
+            }
+        }
+        if ($this->assignment->get_instance()->allowsubmissionsfromdate && $data['extensionduedate']) {
+            if ($this->assignment->get_instance()->allowsubmissionsfromdate > $data['extensionduedate']) {
+                $errors['extensionduedate'] = get_string('extensionnotafterfromdate', 'assign');
+            }
+        }
+
+        return $errors;
+    }
+}
\ No hay ningún carácter de nueva línea al final del archivo
diff -Naur assign/gradingtable.php assign23/gradingtable.php
--- assign/gradingtable.php	2012-06-24 21:33:37.000000000 +0100
+++ assign23/gradingtable.php	2012-06-25 19:07:27.000000000 +0100
@@ -90,7 +90,7 @@
 
         $fields = user_picture::fields('u') . ', u.id as userid, u.firstname as firstname, u.lastname as lastname, ';
         $fields .= 's.status as status, s.id as submissionid, s.timecreated as firstsubmission, s.timemodified as timesubmitted, ';
-        $fields .= 'g.id as gradeid, g.grade as grade, g.timemodified as timemarked, g.timecreated as firstmarked, g.mailed as mailed, g.locked as locked';
+        $fields .= 'g.id as gradeid, g.grade as grade, g.timemodified as timemarked, g.timecreated as firstmarked, g.mailed as mailed, g.locked as locked, g.extensionduedate as extensionduedate';
         $from = '{user} u LEFT JOIN {assign_submission} s ON u.id = s.userid AND s.assignment = :assignmentid1' .
                         ' LEFT JOIN {assign_grades} g ON u.id = g.userid AND g.assignment = :assignmentid2';
 
@@ -409,7 +409,28 @@
 
             $o .= $this->output->container(get_string('submissionstatus_' . $row->status, 'assign'), array('class'=>'submissionstatus' .$row->status));
             if ($this->assignment->get_instance()->duedate && $row->timesubmitted > $this->assignment->get_instance()->duedate) {
+                /// TODO test if get_duedate before is better 
+                // past standard duedate - check for extension date
+                if (!$row->extensionduedate || $row->timesubmitted > $row->extensionduedate) {
                 $o .= $this->output->container(get_string('submittedlateshort', 'assign', format_time($row->timesubmitted - $this->assignment->get_instance()->duedate)), 'latesubmission');
+                }
+            }
+            /// TODO test what is this
+            if (!$row->timesubmitted) {
+                $now = time();
+                $due = $this->assignment->get_instance()->duedate;
+                // check for extension date
+                if ($row->extensionduedate) {
+                    $due = $row->extensionduedate;
+                }
+                if ($due && ($now > $due)) {
+                    // no submission and it is late
+                    $o .= $this->output->container(get_string('overdue', 'assign', format_time($now - $due)), 'overduesubmission');
+                }
+            }
+            // print any current extension date
+            if ($row->extensionduedate) {
+                $o .= $this->output->container(get_string('userextensiondate', 'assign', userdate($row->extensionduedate)), 'extensiondate');
             }
             if ($row->locked) {
                 $o .= $this->output->container(get_string('submissionslockedshort', 'assign'), 'lockedsubmission');
@@ -448,6 +469,7 @@
         }
         $actions[$url->out(false)] = $description;
 
+        if ($this->assignment->is_any_submission_plugin_enabled()) {
         if (!$row->status || $row->status == ASSIGN_SUBMISSION_STATUS_DRAFT || !$this->assignment->get_instance()->submissiondrafts) {
             if (!$row->locked) {
                 $url = new moodle_url('/mod/assign/view.php', array('id' => $this->assignment->get_course_module()->id,
@@ -476,7 +498,15 @@
             $description = get_string('reverttodraftshort', 'assign');
             $actions[$url->out(false)] = $description;
         }
+            $url = new moodle_url('/mod/assign/view.php', array('id' => $this->assignment->get_course_module()->id,
+                                                                'userid'=>$row->id,
+                                                                'action'=>'grantextension',
+                                                                'sesskey'=>sesskey(),
+                                                                'page'=>$this->currpage));
 
+            $description = get_string('grantextension', 'assign');
+            $actions[$url->out(false)] = $description;
+        }
         $edit .= $this->output->container_start(array('yui3-menu', 'actionmenu'), 'actionselect' . $row->id);
         $edit .= $this->output->container_start(array('yui3-menu-content'));
         $edit .= html_writer::start_tag('ul');
diff -Naur assign/lang/en/assign.php assign23/lang/en/assign.php
--- assign/lang/en/assign.php	2012-06-24 21:33:37.000000000 +0100
+++ assign23/lang/en/assign.php	2012-06-25 19:52:48.000000000 +0100
@@ -89,6 +89,10 @@
 $string['duedatevalidation'] = 'Due date must be after the allow submissions from date.';
 $string['editsubmission'] = 'Edit my submission';
 $string['editaction'] = 'Actions...';
+$string['extensionscount'] = '{$a} users allowed extended due date';
+$string['extensionduedate'] = 'Extension due date';
+$string['extensionnotafterduedate'] = 'Extension date must be after the due date';
+$string['extensionnotafterfromdate'] = 'Extension date must be after the allow submissions from date';
 $string['gradersubmissionupdatedtext'] = '{$a->username} has updated their assignment submission
 for \'{$a->assignment}\' at {$a->timeupdated}
 
@@ -138,10 +142,12 @@
 $string['gradingstatus'] = 'Grading status';
 $string['gradingstudentprogress'] = 'Grading student {$a->index} of {$a->count}';
 $string['gradingsummary'] = 'Grading summary';
+$string['grantextension'] = 'Grant extension';
 $string['hideshow'] = 'Hide/Show';
 $string['instructionfiles'] = 'Instruction files';
 $string['invalidgradeforscale'] = 'The grade supplied was not valid for the current scale';
 $string['invalidfloatforgrade'] = 'The grade provided could not be understood: {$a}';
+$string['latesubmissions'] = 'Late submissions';
 $string['lastmodifiedsubmission'] = 'Last modified (submission)';
 $string['lastmodifiedgrade'] = 'Last modified (grade)';
 $string['locksubmissionforstudent'] = 'Prevent any more submissions for student: (id={$a->id}, fullname={$a->fullname}).';
@@ -164,6 +170,8 @@
 $string['noonlinesubmissions'] = 'This assignment does not require you to submit anything online';
 $string['nosavebutnext'] = 'Next';
 $string['nosubmission'] = 'Nothing has been submitted for this assignment';
+$string['nosubmissionsaccepted'] = 'No more submissions accepted';
+$string['nomoresubmissionsaccepted'] = 'No more submissions accepted without an extension';
 $string['notgraded'] = 'Not graded';
 $string['notgradedyet'] = 'Not graded yet';
 $string['notsubmittedyet'] = 'Not submitted yet';
@@ -173,6 +181,7 @@
 $string['numberofparticipants'] = 'Participants';
 $string['numberofsubmittedassignments'] = 'Submitted';
 $string['offline'] = 'No online submissions required';
+$string['open'] = 'Open';
 $string['overdue'] = '<font color="red">Assignment is overdue by: {$a}</font>';
 $string['outlinegrade'] = 'Grade: {$a}';
 $string['page-mod-assign-x'] = 'Any assignment module page';
@@ -248,6 +257,7 @@
 $string['updategrade'] = 'Update grade';
 $string['updatetable'] = 'Save and update table';
 $string['upgradenotimplemented'] = 'Upgrade not implemented in plugin ({$a->type} {$a->subtype})';
+$string['userextensiondate'] = 'Extension granted until: {$a}';
 $string['viewfeedback'] = 'View feedback';
 $string['viewfeedbackforuser'] = 'View feedback for user: {$a}';
 $string['viewfullgradingpage'] = 'Open the full grading page to provide feedback';
diff -Naur assign/locallib.php assign23/locallib.php
--- assign/locallib.php	2012-06-24 21:33:37.000000000 +0100
+++ assign23/locallib.php	2012-06-25 20:36:29.000000000 +0100
@@ -346,6 +346,11 @@
         }else if ($action == 'saveoptions') {
             $this->process_save_grading_options();
             $action = 'grading';
+        } else if ($action == 'saveextension') {
+            $action = 'grantextension';
+            if ($this->process_save_extension($mform)) {
+                $action = 'grading';
+            }
         }
 
         $returnparams = array('rownum'=>optional_param('rownum', 0, PARAM_INT));
@@ -361,6 +366,8 @@
         } else if ($action == 'nextgrade') {
             $mform = null;
             $o .= $this->view_single_grade_page($mform, 1);
+        } else if ($action == 'grantextension') {
+            $o .= $this->view_grant_extension($mform);
         } else if ($action == 'grade') {
             $o .= $this->view_single_grade_page($mform);
         } else if ($action == 'viewpluginassignfeedback') {
@@ -981,6 +988,21 @@
                                           status = ?", array($this->get_course_module()->instance, $status));
     }
 
+
+    /**
+     * Load a count of users enrolled in the current course with the specified permission and group (optional)
+     *
+     * @param string $status The submission status - should match one of the constants
+     * @return int number of matching submissions
+     */
+    public function count_extended_submissions() {
+        global $DB;
+
+        return $DB->count_records_select('assign_grades', ' assignment = ? AND extensionduedate > ? ',
+                                array($this->get_course_module()->instance, time()));
+    }
+
+
     /**
      * Utility function to get the userid for every row in the grading table
      * so the order can be frozen while we iterate it
@@ -1243,6 +1265,51 @@
     }
 
     /**
+     * view the grant extension date page
+     *
+     * Uses url parameters 'userid'
+     * @global moodle_database $DB
+     * @global stdClass $CFG
+     * @return string
+     */
+    private function view_grant_extension($mform) {
+        global $DB, $CFG;
+
+        $o = '';
+
+        $userid = required_param('userid', PARAM_INT);
+        require_once($CFG->dirroot . '/mod/assign/extensionform.php');
+
+        $grade = $this->get_user_grade($userid, false);
+
+        $user = $DB->get_record('user', array('id'=>$userid), '*', MUST_EXIST);
+
+        $data = new stdClass();
+
+        if ($grade) {
+            $data->extensionduedate = $grade->extensionduedate;
+        } else {
+            $data->extensionduedate = null;
+        }
+        $data->userid = $userid;
+
+        $o .= $this->output->render(new assign_header($this->get_instance(),
+                                                      $this->get_context(),
+                                                      $this->show_intro(),
+                                                      $this->get_course_module()->id,
+                                                      get_string('grantextension', 'assign')));
+        if (!$mform) {
+            $mform = new mod_assign_extension_form(null, array($this, $user, $data));
+        }
+
+        $o .= $this->output->render(new assign_user_summary($user, $this->get_course()->id, has_capability('moodle/site:viewfullnames', $this->get_course_context())));
+        $o .= $this->output->render($mform);
+
+        $o .= $this->view_footer();
+        return $o;
+    }
+
+    /**
      * display the submission that is used by a plugin
      * Uses url parameters 'sid', 'gid' and 'plugin'
      * @param string $pluginsubtype
@@ -1623,7 +1690,15 @@
         // get the current grade
         $grade = $this->get_user_grade($userid, false);
         if ($this->can_view_submission($userid)) {
+            $showedit = has_capability('mod/assign:submit', $this->context) &&
+                         $this->submissions_open($userid) && ($this->is_any_submission_plugin_enabled());
+
+            $showsubmit = $showedit && $submission && ($submission->status == ASSIGN_SUBMISSION_STATUS_DRAFT);
             $gradelocked = ($grade && $grade->locked) || $this->grading_disabled($userid);
+            $extensionduedate = null;
+            if ($grade) {
+                $extensionduedate = $grade->extensionduedate;
+            }
             $o .= $this->output->render(new assign_submission_status($this->get_instance()->allowsubmissionsfromdate,
                                                               $this->get_instance()->alwaysshowdescription,
                                                               $submission,
@@ -1636,8 +1711,9 @@
                                                               $this->get_return_params(),
                                                               $this->get_course_module()->id,
                                                               assign_submission_status::GRADER_VIEW,
-                                                              false,
-                                                              false));
+                                                              $showedit,
+                                                              $showsubmit,
+                                                              $extensionduedate));
         }
         if ($grade) {
             $data = new stdClass();
@@ -1999,6 +2075,11 @@
             $showsubmit = $submission && ($submission->status == ASSIGN_SUBMISSION_STATUS_DRAFT) && $showlinks;
             $gradelocked = ($grade && $grade->locked) || $this->grading_disabled($user->id);
 
+            $extensionduedate = null;
+
+            if ($grade) {
+                $extensionduedate = $grade->extensionduedate;
+            }
             $o .= $this->output->render(new assign_submission_status($this->get_instance()->allowsubmissionsfromdate,
                                                               $this->get_instance()->alwaysshowdescription,
                                                               $submission,
@@ -2012,7 +2093,8 @@
                                                               $this->get_course_module()->id,
                                                               assign_submission_status::STUDENT_VIEW,
                                                               $showedit,
-                                                              $showsubmit));
+                                                              $showsubmit,
+                                                              $extensionduedate));
             require_once($CFG->libdir.'/gradelib.php');
             require_once($CFG->dirroot.'/grade/grading/lib.php');
 
@@ -2094,7 +2176,8 @@
                                                             $this->is_any_submission_plugin_enabled(),
                                                             $this->count_submissions_with_status(ASSIGN_SUBMISSION_STATUS_SUBMITTED),
                                                             $this->get_instance()->duedate,
-                                                            $this->get_course_module()->id
+                                                            $this->get_course_module()->id,
+                                                            $this->count_extended_submissions()
                                                             ));
         }
         $grade = $this->get_user_grade($USER->id, false);
@@ -2199,33 +2282,88 @@
         return $result;
     }
 
+
+    /**
+     * Calculates submission due date for a particular user (taking xtensions
+     * (taking extensions into account)
+     *
+     * @param int $userID number
+     * @return int duedate timestamp
+     */
+    private function get_user_duedate($userid = null) {
+        global $DB;
+
+        if (!$userid) {
+            $userid = $USER->id;
+        }
+
+        $duedate = $this->get_instance()->duedate;
+        $extension = 0;
+        if($grade = $DB->get_record('assign_grades', array('assignment'=>$this->get_instance()->id, 'userid'=>$userid)) ) {
+        }
+        return max($duedate, $extension);
+    }
+
+
     /**
      * Is this assignment open for submissions?
      *
-     * Check the due date,
+     * Check the due date for this user,
      * prevent late submissions,
      * has this person already submitted,
      * is the assignment locked?
      *
+     * @param int $userID number
      * @return bool
      */
-    private function submissions_open() {
+    private function submissions_open($userid = null) {
         global $USER;
 
+        if (!$userid) {
+            $userid = $USER->id;
+        }
+
+//////////////////////////////
+////  old
+
         $time = time();
+        $duedate = $this->get_user_duedate($userid);
         $dateopen = true;
-        if ($this->get_instance()->preventlatesubmissions && $this->get_instance()->duedate) {
-            $dateopen = ($this->get_instance()->allowsubmissionsfromdate <= $time && $time <= $this->get_instance()->duedate);
+        if ($this->get_instance()->preventlatesubmissions && $duedate) {
+            $dateopen = ($this->get_instance()->allowsubmissionsfromdate <= $time && $time <= $duedate);
+        } else {
+            $dateopen = ($this->get_instance()->allowsubmissionsfromdate <= $time);
+        }
+
+////////////////////////////////////
+///// new extension
+/*
+        if ($this->get_instance()->duedate) {
+            if ($this->get_instance()->cutoffdate) {
+                $dateopen = ($this->get_instance()->allowsubmissionsfromdate <= $time && $time <= $this->get_instance()->cutoffdate);
+            } else {
+                $dateopen = ($this->get_instance()->allowsubmissionsfromdate <= $time && $time <= $this->get_instance()->duedate);
+            }
+            if (!$dateopen) {
+                $grade = $this->get_user_grade($userid, false);
+                if ($grade && $grade->extensionduedate) {
+                    $dateopen = ($this->get_instance()->allowsubmissionsfromdate <= $time) &&
+                                ($time <= $grade->extensionduedate);
+                }
+            }
         } else {
             $dateopen = ($this->get_instance()->allowsubmissionsfromdate <= $time);
         }
+*/
+/////////////////////////
+
 
         if (!$dateopen) {
             return false;
         }
 
         // now check if this user has already submitted etc.
-        if (!is_enrolled($this->get_course_context(), $USER)) {
+        if (!is_enrolled($this->get_course_context(), $userid)) {
             return false;
         }
         if ($submission = $this->get_user_submission($USER->id, false)) {
@@ -2240,7 +2378,7 @@
             }
         }
 
-        if ($this->grading_disabled($USER->id)) {
+        if ($this->grading_disabled($userid)) {
             return false;
         }
 
@@ -2495,6 +2633,44 @@
         }
     }
 
+
+    /**
+     * save extension date for a single student
+     *
+     * @param moodleform $mform The submitted form
+     * @return boolean - if false - next page will be the extension form again
+     */
+    private function process_save_extension(&$mform) {
+        global $DB, $CFG;
+
+        // Include extension form
+        require_once($CFG->dirroot . '/mod/assign/extensionform.php');
+        require_sesskey();
+
+        // Need grade permission to grant extensions
+        require_capability('mod/assign:grade', $this->context);
+
+        $userid = required_param('userid', PARAM_INT);
+
+        $user = $DB->get_record('user', array('id'=>$userid), '*', MUST_EXIST);
+
+        $mform = new mod_assign_extension_form(null, array($this, $user, null));
+
+        if ($mform->is_cancelled()) {
+            return true;
+        }
+
+        if ($formdata = $mform->get_data()) {
+            $grade = $this->get_user_grade($userid, true);
+            $grade->extensionduedate = $formdata->extensionduedate;
+            $grade->timemodified = time();
+
+            return $DB->update_record('assign_grades', $grade);
+        }
+        return false;
+    }
+
+
     /**
      * save quick grades
      *
diff -Naur assign/renderable.php assign23/renderable.php
--- assign/renderable.php	2012-06-18 14:27:52.000000000 +0100
+++ assign23/renderable.php	2012-06-25 19:42:14.000000000 +0100
@@ -308,6 +308,8 @@
     var $canedit = false;
     /** @var bool cansubmit */
     var $cansubmit = false;
+    /** @var int extensionduedate */
+    var $extensionduedate = 0;
 
     /**
      * constructor
@@ -326,10 +328,11 @@
      * @param string $view
      * @param bool $canedit
      * @param bool $cansubmit
+     * @param int $extensionduedate
      */
     public function __construct($allowsubmissionsfromdate, $alwaysshowdescription, $submission, $submissionsenabled,
                                 $locked, $graded, $duedate, $submissionplugins, $returnaction, $returnparams,
-                                $coursemoduleid, $view, $canedit, $cansubmit) {
+                                $coursemoduleid, $view, $canedit, $cansubmit, $extensionduedate) {
         $this->allowsubmissionsfromdate = $allowsubmissionsfromdate;
         $this->alwaysshowdescription = $alwaysshowdescription;
         $this->submission = $submission;
@@ -344,6 +347,7 @@
         $this->view = $view;
         $this->canedit = $canedit;
         $this->cansubmit = $cansubmit;
+        $this->extensionduedate = $extensionduedate;
     }
 
 }
@@ -401,6 +405,8 @@
     var $submissiondraftsenabled = false;
     /** @var int submissiondraftscount - The number of submissions in draft status */
     var $submissiondraftscount = 0;
+    /** @var int extensionscount - The number of due date extensions in this assignment */
+    var $extensionscount = 0;
     /** @var bool submissionsenabled - Allow submissions */
     var $submissionsenabled = false;
     /** @var int submissionssubmittedcount - The number of submissions in submitted status */
@@ -410,6 +416,7 @@
     /** @var int coursemoduleid - The assignment course module id */
     var $coursemoduleid = 0;
 
+
     /**
      * constructor
      *
@@ -421,7 +428,7 @@
      * @param int $duedate
      * @param int $coursemoduleid
      */
-    public function __construct($participantcount, $submissiondraftsenabled, $submissiondraftscount, $submissionsenabled, $submissionssubmittedcount, $duedate, $coursemoduleid) {
+    public function __construct($participantcount, $submissiondraftsenabled, $submissiondraftscount, $submissionsenabled, $submissionssubmittedcount, $duedate, $coursemoduleid, $extensionscount = 0) {
         $this->participantcount = $participantcount;
         $this->submissiondraftsenabled = $submissiondraftsenabled;
         $this->submissiondraftscount = $submissiondraftscount;
@@ -429,6 +436,7 @@
         $this->submissionssubmittedcount = $submissionssubmittedcount;
         $this->duedate = $duedate;
         $this->coursemoduleid = $coursemoduleid;
+        $this->extensionscount = $extensionscount;
     }
 
 
diff -Naur assign/renderer.php assign23/renderer.php
--- assign/renderer.php	2012-06-24 21:33:37.000000000 +0100
+++ assign23/renderer.php	2012-06-25 20:47:57.000000000 +0100
@@ -87,6 +87,21 @@
     }
 
     /**
+* Render the grant extension form
+* @param mod_assign_extension_form $form The extension date form to render
+* @return string
+*/
+    public function render_mod_assign_extension_form(mod_assign_extension_form $form) {
+        $o = '';
+
+        $o .= $this->output->box_start('boxaligncenter grantextension');
+        $o .= $this->moodleform($form);
+        $o .= $this->output->box_end();
+        return $o;
+    }
+
+
+    /**
      * Render a grading error notification
      * @param assign_quickgrading_result $result The result to render
      * @return string
@@ -260,12 +275,18 @@
 
             // time remaining
             $due = '';
-            if ($duedate - $time <= 0) {
+            /// TODO checj if get_duedate is betetr ecastro ULPGC
+            if ($duedate < $time) { // extension
                 $due = get_string('assignmentisdue', 'assign');
             } else {
                 $due = format_time($duedate - $time);
             }
             $this->add_table_row_tuple($t, get_string('timeremaining', 'assign'), $due);
+            if ($duedate < $time) {
+                if ($summary->extensionscount) {
+                    $this->add_table_row_tuple($t, get_string('latesubmissions', 'assign'), get_string('extensionscount', 'assign', $summary->extensionscount));
+                }
+            }
         }
 
         // all done - write the table
@@ -407,13 +428,21 @@
 
 
         $duedate = $status->duedate;
-        if ($duedate >= 1) {
+        if ($duedate > 0) {
             $row = new html_table_row();
             $cell1 = new html_table_cell(get_string('duedate', 'assign'));
             $cell2 = new html_table_cell(userdate($duedate));
             $row->cells = array($cell1, $cell2);
             $t->data[] = $row;
 
+            if ($status->extensionduedate) {
+                $row = new html_table_row();
+                $cell1 = new html_table_cell(get_string('extensionduedate', 'assign'));
+                $cell2 = new html_table_cell(userdate($status->extensionduedate));
+                $row->cells = array($cell1, $cell2);
+                $t->data[] = $row;
+                $duedate = $status->extensionduedate;
+            }
             // time remaining
             $row = new html_table_row();
             $cell1 = new html_table_cell(get_string('timeremaining', 'assign'));
@@ -440,7 +469,22 @@
             $row->cells = array($cell1, $cell2);
             $t->data[] = $row;
         }
-
+/*
+        /// extensions ????? 
+        if ($status->view == assign_submission_status::GRADER_VIEW) {
+            $row = new html_table_row();
+            $cell1 = new html_table_cell(get_string('open', 'assign'));
+            if ($status->canedit) {
+                $cell2 = new html_table_cell(get_string('submissioneditable', 'assign'));
+                $cell2->attributes = array('class'=>'submissioneditable');
+            } else {
+                $cell2 = new html_table_cell(get_string('submissionnoteditable', 'assign'));
+                $cell2->attributes = array('class'=>'submissionnoteditable');
+            }
+            $row->cells = array($cell1, $cell2);
+            $t->data[] = $row;
+        }
+*/
         // last modified
         if ($status->submission) {
             $row = new html_table_row();
diff -Naur assign/submission/resubmission/db/access.php assign23/submission/resubmission/db/access.php
--- assign/submission/resubmission/db/access.php	1970-01-01 00:00:00.000000000 +0000
+++ assign23/submission/resubmission/db/access.php	2012-06-03 09:55:42.000000000 +0100
@@ -0,0 +1,30 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Capability definitions for this module.
+ *
+ * @package assignsubmission_resubmission
+ * @copyright  2012 Enrique Castro, ULPGC
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+
+$capabilities = array(
+
+
+
+);
diff -Naur assign/submission/resubmission/db/install.php assign23/submission/resubmission/db/install.php
--- assign/submission/resubmission/db/install.php	1970-01-01 00:00:00.000000000 +0000
+++ assign23/submission/resubmission/db/install.php	2012-06-03 09:58:22.000000000 +0100
@@ -0,0 +1,51 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Post-install code for the submission_comments module.
+ *
+ * @package assignsubmission_resubmission
+ * @copyright  2012 Enrique Castro, ULPGC
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+
+defined('MOODLE_INTERNAL') || die();
+
+
+/**
+ * Code run after the module database tables have been created.
+ * Moves the comments plugin to the bottom
+ * @return bool
+ */
+function xmldb_assignsubmission_resubmission_install() {
+    global $CFG;
+
+    // do the install
+
+    require_once($CFG->dirroot . '/mod/assign/adminlib.php');
+    // set the correct initial order for the plugins
+    $pluginmanager = new assign_plugin_manager('assignsubmission');
+
+    $pluginmanager->move_plugin('resubmission', 'down');
+    $pluginmanager->move_plugin('resubmission', 'down');
+    $pluginmanager->move_plugin('resubmission', 'down');
+
+    // do the upgrades
+    return true;
+
+
+}
diff -Naur assign/submission/resubmission/db/upgrade.php assign23/submission/resubmission/db/upgrade.php
--- assign/submission/resubmission/db/upgrade.php	1970-01-01 00:00:00.000000000 +0000
+++ assign23/submission/resubmission/db/upgrade.php	2012-06-03 09:58:57.000000000 +0100
@@ -0,0 +1,34 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Upgrade code for install
+ *
+ * @package assignsubmission_resubmission
+ * @copyright  2012 Enrique Castro, ULPGC
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+/**
+ * Stub for upgrade code
+ * @param int $oldversion
+ * @return bool
+ */
+function xmldb_submission_resubmission_upgrade($oldversion) {
+    return true;
+}
+
+
diff -Naur assign/submission/resubmission/lang/en/assignsubmission_resubmission.php assign23/submission/resubmission/lang/en/assignsubmission_resubmission.php
--- assign/submission/resubmission/lang/en/assignsubmission_resubmission.php	1970-01-01 00:00:00.000000000 +0000
+++ assign23/submission/resubmission/lang/en/assignsubmission_resubmission.php	2012-06-03 11:24:33.000000000 +0100
@@ -0,0 +1,49 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Strings for component 'submission_resubmission', language 'en'
+ *
+ * @package assignsubmission_resubmission
+ * @copyright  2012 Enrique Castro, ULPGC
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+$string['default'] = 'Enabled by default';
+$string['default_help'] = 'If set, this submission method will be enabled by default for all new assignments.';
+$string['enabled'] = 'Resubmissions policy';
+$string['enabled_help'] = '
+If enabled, students will be able to re-submit their assignment (within the submision time window) according to some rules.
+';
+$string['pluginname'] = 'Resubmissions';
+
+$string['limitbymode'] = 'Allow resubmissions';
+$string['limitbymode_help'] = '
+This option determine when are resubmissions allowed to a given student.
+The possible options are:
+
+* Graded: students that are graded can submit (either exists a previous submision or not). Students without previous submissions can still submit.
+* Submitted and graded: only students that have already submitted and assignment can resubmit. That is, students that have not submitted previouslu cannot submit, even when assignment time window is open.
+* Always: students can resubmit freely while submission time window is open.
+
+';
+$string['limitbyfinal'] = 'after submission and grading';
+$string['limitbygrade'] = 'after grading';
+$string['limitbytime'] = 'always';
+
+$string['viewresubmissionno'] = 'Resubmissions allowed {$a} ';
+
+
diff -Naur assign/submission/resubmission/lib.php assign23/submission/resubmission/lib.php
--- assign/submission/resubmission/lib.php	1970-01-01 00:00:00.000000000 +0000
+++ assign23/submission/resubmission/lib.php	2012-06-03 09:43:13.000000000 +0100
@@ -0,0 +1,67 @@
+<?PHP
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * This file contains the moodle hooks for the submission resubmission plugin
+ *
+ * @package   assignsubmission_resubmission
+ * @copyright  2012 Enrique Castro, ULPGC
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ *
+ * Callback method for data validation---- required method for AJAXmoodle based comment API
+ *
+ * @param stdClass $options
+ * @return bool
+ */
+function assignsubmission_resubmission_comment_validate(stdClass $options) {
+
+    return true;
+}
+
+/**
+ * Permission control method for submission plugin ---- required method for AJAXmoodle based comment API
+ *
+ * @param stdClass $options
+ * @return array
+ */
+function assignsubmission_resubmission_comment_permissions(stdClass $options) {
+
+    return array('post' => true, 'view' => true);
+}
+
+// /**
+//  * Callback to force the userid for all comments to be the userid of the submission and NOT the global $USER->id. This
+//  * is required by the upgrade code. Note the comment area is used to identify upgrades.
+//  *
+//  * @param stdClass $comment
+//  * @param stdClass $param
+//  */
+// function assignsubmission_resubmission_comment_add(stdClass $comment, stdClass $param) {
+//
+//     global $DB;
+//     if ($comment->commentarea == 'submission_resubmission_upgrade') {
+//         $submissionid = $comment->itemid;
+//         $submission = $DB->get_record('assign_submission', array('id' => $submissionid));
+//
+//         $comment->userid = $submission->userid;
+//         $comment->commentarea = 'submission_resubmission';
+//     }
+// }
+
diff -Naur assign/submission/resubmission/locallib.php assign23/submission/resubmission/locallib.php
--- assign/submission/resubmission/locallib.php	1970-01-01 00:00:00.000000000 +0000
+++ assign23/submission/resubmission/locallib.php	2012-06-03 14:57:17.000000000 +0100
@@ -0,0 +1,166 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * This file contains the definition for the library class for view resubmission submission plugin
+ *
+ * @package assignsubmission_resubmission
+ * @copyright  2012 Enrique Castro, ULPGC
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+ defined('MOODLE_INTERNAL') || die();
+
+ /** Include submissionplugin.php */
+ require_once($CFG->dirroot . '/mod/assign/submissionplugin.php');
+
+/**
+ * This file contains the definition for the library class for view resubmission submission plugin
+ *
+ * @package assignsubmission_resubmission
+ * @copyright  2012 Enrique Castro, ULPGC
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class assign_submission_resubmission extends assign_submission_plugin {
+
+   /**
+    * get the name of the view resubmission submission plugin
+    * @return string
+    */
+    public function get_name() {
+        return get_string('pluginname', 'assignsubmission_resubmission');
+    }
+
+
+    /**
+     * Get the default setting for peer submission plugin
+     *
+     * @param MoodleQuickForm $mform The form to add elements to
+     * @return void
+     */
+    public function get_settings(MoodleQuickForm $mform) {
+        global $CFG, $COURSE;
+
+        $defaultlimitmode = $this->get_config('resubmissioncontrol');
+        /*
+        if(!$defaultlimitmode) {
+            $defaultlimitmode = get_config('assignsubmission_resubmission', 'resubmissioncontrol');
+        }
+        */
+
+        $options = array('grade'=>get_string('limitbygrade', 'assignsubmission_resubmission'),
+                            'final'=>get_string('limitbyfinal', 'assignsubmission_resubmission'),
+                            'time'=>get_string('limitbytime', 'assignsubmission_resubmission')
+                            );
+        $mform->addElement('select', 'assignsubmission_resubmission_resubmissioncontrol', get_string('limitbymode', 'assignsubmission_resubmission'), $options);
+        $mform->addHelpButton('assignsubmission_resubmission_resubmissioncontrol', 'limitbymode', 'assignsubmission_resubmission');
+        $mform->setDefault('assignsubmission_resubmission_resubmissioncontrol', $defaultlimitmode);
+        $mform->disabledIf('assignsubmission_resubmission_resubmissioncontrol', 'assignsubmission_resubmission_enabled', 'eq', 0);
+    }
+
+    /**
+     * Save the settings for peer submission plugin
+     *
+     * @param stdClass $data
+     * @return bool
+     */
+    public function save_settings(stdClass $data) {
+        $this->set_config('resubmissioncontrol', $data->assignsubmission_resubmission_resubmissioncontrol);
+        return true;
+    }
+
+   /**
+    * display AJAX based comment in the submission status table
+    *
+    * @param stdClass $submission
+    * @param bool $showviewlink - If the comments are long this is set to true so they can be shown in a separate page
+    * @return string
+    */
+   public function view_summary(stdClass $submission, & $showviewlink) {
+        global $CFG, $DB, $USER, $OUTPUT;
+        // never show a link to view full submission
+        $showviewlink = false;
+        $instance = $this->assignment->get_instance();
+        $link = '';
+
+        if ($this->assignment->is_any_submission_plugin_enabled()) {
+            $is_open = false;
+            $mode = $this->get_config('resubmissioncontrol');
+            switch ($mode) {
+                case 'grade' :  //$is_open = !$this->assignment->is_graded($USER->id);
+                                $link= get_string('viewresubmissionno', 'assignsubmission_resubmission', get_string('limitbygrade', 'assignsubmission_resubmission'));
+                                break;
+                case 'final':  //$is_open = $this->assignment->submissions_open();
+                                $link= get_string('viewresubmissionno', 'assignsubmission_resubmission', get_string('limitbyfinal', 'assignsubmission_resubmission'));
+                                break;
+                case 'time'  :  //$is_open = ($time <= $instance()->duedate);
+                                $link= get_string('viewresubmissionno', 'assignsubmission_resubmission', get_string('limitbytime', 'assignsubmission_resubmission'));
+                                break;
+            }
+        }
+        return format_string($link);
+
+    }
+
+    /**
+     * Always return false because only active if exist submission
+     * @param stdClass $submission
+     * @return bool
+     */
+    public function is_empty(stdClass $submission) {
+        return false;
+    }
+
+    /**
+     * The submission view resubmission plugin has no submission component per se so should not be counted
+     * when determining whether to show the edit submission link.
+     * @return boolean
+     */
+    public function allow_submissions() {
+        return false;
+    }
+
+    /**
+     * Check if the submission plugin is open for submissions by a user
+     * @param int $userid user ID
+     * @return bool|string 'true' if OK to proceed with submission, otherwise a
+     *                        a message to display to the user
+     */
+    public function is_open($userid=0) {
+        global $DB, $USER;
+
+        $instance = $this->assignment->get_instance();
+        $instance->submissiondrafts = 0;
+        $this->assignment->set_instance($instance);
+        $is_open = true;
+        if ($this->assignment->is_any_submission_plugin_enabled()) {
+            $mode = $this->get_config('resubmissioncontrol');
+            $grade = $DB->get_record('assign_grades', array('assignment'=>$instance->id, 'userid'=>$USER->id));
+            $submission = $DB->get_record('assign_submission', array('assignment'=>$instance->id, 'userid'=>$USER->id));
+            $grade = (bool)($grade AND ($grade->timemodified > $submission->timemodified));
+            switch ($mode) {
+                case 'grade' :  $is_open = (bool)(!$submission OR $grade);
+                                break;
+                case 'final':   $is_open = (bool)($submission AND $grade);
+                                break;
+                case 'time'  :
+                                break;
+            }
+        }
+        return $is_open;
+    }
+
+}
diff -Naur assign/submission/resubmission/version.php assign23/submission/resubmission/version.php
--- assign/submission/resubmission/version.php	1970-01-01 00:00:00.000000000 +0000
+++ assign23/submission/resubmission/version.php	2012-06-03 11:19:49.000000000 +0100
@@ -0,0 +1,28 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * This file contains the version information for the resubmission submission plugin
+ *
+ * @package assignsubmission_resubmission
+ * @copyright  2012 Enrique Castro, ULPGC
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+$plugin->version   = 2012060100;
+$plugin->requires  = 2012060100;
+
+$plugin->component = 'assignsubmission_resubmission';