From b244b9b776b05b10bd61f9d2d653fa8aa8befc26 Mon Sep 17 00:00:00 2001
From: nicolasconnault <nicolasconnault>
Date: Fri, 18 Apr 2008 19:30:28 +0000
Subject: [PATCH] MDL-14163 YUI implementation complete, new grader_report
 preference and admin setting for enabling ajax.

---
 grade/lib.php                            | 119 ++++-
 grade/report/grader/ajax.php             | 582 +++++++++++++++++++++++
 grade/report/grader/ajax_callbacks.php   | 139 ++++++
 grade/report/grader/ajaxlib.php          | 527 ++++++++++++++++++++
 grade/report/grader/index.php            |  52 +-
 grade/report/grader/preferences_form.php |   2 +-
 grade/report/grader/settings.php         |   4 +-
 lang/en_utf8/grades.php                  |   1 +
 lib/ajax/ajaxlib.php                     |   3 +
 9 files changed, 1412 insertions(+), 17 deletions(-)
 create mode 100644 grade/report/grader/ajax.php
 create mode 100644 grade/report/grader/ajax_callbacks.php
 create mode 100644 grade/report/grader/ajaxlib.php

diff --git a/grade/lib.php b/grade/lib.php
index 79228c744d..a4952a2986 100644
--- a/grade/lib.php
+++ b/grade/lib.php
@@ -987,7 +987,7 @@ class grade_structure {
         }
 
         if ($url) {
-            return '<a href="'.$url.'"><img '.$overlib.' src="'.$CFG->pixpath.'/t/edit.gif" class="iconsmall" alt="'.$stredit.'" title="'.$stredit.'"/></a>';
+            return '<a href="'.$url.'" class="edit"><img '.$overlib.' src="'.$CFG->pixpath.'/t/edit.gif" class="iconsmall" alt="'.$stredit.'" title="'.$stredit.'"/></a>';
 
         } else {
             return '';
@@ -1022,13 +1022,13 @@ class grade_structure {
             $url     = $CFG->wwwroot.'/grade/edit/tree/action.php?id='.$this->courseid.'&amp;action=show&amp;sesskey='.sesskey()
                      . '&amp;eid='.$element['eid'];
             $url     = $gpr->add_url_params($url);
-            $action  = '<a href="'.$url.'"><img alt="'.$strshow.'" src="'.$CFG->pixpath.'/t/'.$icon.'.gif" class="iconsmall" title="'.$tooltip.'"/></a>';
+            $action  = '<a href="'.$url.'" class="hide"><img alt="'.$strshow.'" src="'.$CFG->pixpath.'/t/'.$icon.'.gif" class="iconsmall" title="'.$tooltip.'"/></a>';
 
         } else {
             $url     = $CFG->wwwroot.'/grade/edit/tree/action.php?id='.$this->courseid.'&amp;action=hide&amp;sesskey='.sesskey()
                      . '&amp;eid='.$element['eid'];
             $url     = $gpr->add_url_params($url);
-            $action  = '<a href="'.$url.'"><img src="'.$CFG->pixpath.'/t/hide.gif" class="iconsmall" alt="'.$strhide.'" title="'.$strhide.'"/></a>';
+            $action  = '<a href="'.$url.'" class="hide"><img src="'.$CFG->pixpath.'/t/hide.gif" class="iconsmall" alt="'.$strhide.'" title="'.$strhide.'"/></a>';
         }
         return $action;
     }
@@ -1066,7 +1066,7 @@ class grade_structure {
             $url     = $CFG->wwwroot.'/grade/edit/tree/action.php?id='.$this->courseid.'&amp;action=unlock&amp;sesskey='.sesskey()
                      . '&amp;eid='.$element['eid'];
             $url     = $gpr->add_url_params($url);
-            $action  = '<a href="'.$url.'"><img src="'.$CFG->pixpath.'/t/'.$icon.'.gif" alt="'.$strunlock.'" class="iconsmall" title="'.$tooltip.'"/></a>';
+            $action  = '<a href="'.$url.'" class="lock"><img src="'.$CFG->pixpath.'/t/'.$icon.'.gif" alt="'.$strunlock.'" class="iconsmall" title="'.$tooltip.'"/></a>';
 
         } else {
             if (!has_capability('moodle/grade:manage', $this->context) and !has_capability('moodle/grade:lock', $this->context)) {
@@ -1075,7 +1075,7 @@ class grade_structure {
             $url     = $CFG->wwwroot.'/grade/edit/tree/action.php?id='.$this->courseid.'&amp;action=lock&amp;sesskey='.sesskey()
                      . '&amp;eid='.$element['eid'];
             $url     = $gpr->add_url_params($url);
-            $action  = '<a href="'.$url.'"><img src="'.$CFG->pixpath.'/t/lock.gif" class="iconsmall" alt="'.$strlock.'" title="'
+            $action  = '<a href="'.$url.'" class="lock"><img src="'.$CFG->pixpath.'/t/lock.gif" class="iconsmall" alt="'.$strlock.'" title="'
                      . $strlock.'"/></a>';
         }
         return $action;
@@ -1111,7 +1111,7 @@ class grade_structure {
                 }
                 $url = $CFG->wwwroot.'/grade/edit/tree/calculation.php?courseid='.$this->courseid.'&amp;id='.$object->id;
                 $url = $gpr->add_url_params($url);
-                $calculation_icon = '<a href="'. $url.'"><img src="'.$CFG->pixpath.'/t/'.$icon.'" class="iconsmall" alt="'
+                $calculation_icon = '<a href="'. $url.'" class="calculation"><img src="'.$CFG->pixpath.'/t/'.$icon.'" class="iconsmall" alt="'
                                        . $streditcalculation.'" title="'.$streditcalculation.'" /></a>'. "\n";
             }
         }
@@ -1548,6 +1548,113 @@ class grade_tree extends grade_structure {
 
         return null;
     }
+    
+    /**
+     * Returns a well-formed XML representation of the grade-tree using recursion.
+     * @param array $root The current element in the recursion. If null, starts at the top of the tree.
+     * @return string $xml
+     */
+    function exportToXML($root=null, $tabs="\t") {
+        $xml = null;
+        $first = false;
+        if (is_null($root)) {
+            $root = $this->top_element;
+            $xml = '<?xml version="1.0" encoding="UTF-8" ?>' . "\n";
+            $xml .= "<gradetree>\n";
+            $first = true;
+        }
+        
+        $type = 'undefined';
+        if (strpos($root['object']->table, 'grade_categories') !== false) {
+            $type = 'category';
+        } elseif (strpos($root['object']->table, 'grade_items') !== false) {
+            $type = 'item';
+        } elseif (strpos($root['object']->table, 'grade_outcomes') !== false) {
+            $type = 'outcome';
+        }
+        
+        $xml .= "$tabs<element type=\"$type\">\n";
+        foreach ($root['object'] as $var => $value) {
+            if (!is_object($value) && !is_array($value) && !empty($value)) {
+                $xml .= "$tabs\t<$var>$value</$var>\n";
+            }
+        }
+
+        if (!empty($root['children'])) {
+            $xml .= "$tabs\t<children>\n";
+            foreach ($root['children'] as $sortorder => $child) {
+                $xml .= $this->exportToXML($child, $tabs."\t\t");
+            }
+            $xml .= "$tabs\t</children>\n";
+        }
+        
+        $xml .= "$tabs</element>\n";
+
+        if ($first) {
+            $xml .= "</gradetree>";
+        }
+        
+        return $xml;
+    }
+    
+    /**
+     * Returns a JSON representation of the grade-tree using recursion.
+     * @param array $root The current element in the recursion. If null, starts at the top of the tree.
+     * @param string $tabs Tab characters used to indent the string nicely for humans to enjoy
+     * @param int    $switch The position (first or last) of the aggregations
+     * @return string $xml
+     */
+    function exportToJSON($root=null, $tabs="\t") {
+        $json = null;
+        $first = false;
+        if (is_null($root)) {
+            $root = $this->top_element;
+            $first = true;
+        }
+        
+        $name = '';
+
+
+        if (strpos($root['object']->table, 'grade_categories') !== false) {
+            $name = $root['object']->fullname;
+            if ($name == '?') {
+                $name = $root['object']->get_name(); 
+            }
+        } elseif (strpos($root['object']->table, 'grade_items') !== false) {
+            $name = $root['object']->itemname;
+        } elseif (strpos($root['object']->table, 'grade_outcomes') !== false) {
+            $name = $root['object']->itemname;
+        }
+        
+        $json .= "$tabs {\n";
+        $json .= "$tabs\t \"type\": \"{$root['type']}\",\n";
+        $json .= "$tabs\t \"name\": \"$name\",\n";
+
+        foreach ($root['object'] as $var => $value) {
+            if (!is_object($value) && !is_array($value) && !empty($value)) {
+                $json .= "$tabs\t \"$var\": \"$value\",\n";
+            }
+        }
+        
+        $json = substr($json, 0, strrpos($json, ','));
+        
+        if (!empty($root['children'])) {
+            $json .= ",\n$tabs\t\"children\": [\n";
+            foreach ($root['children'] as $sortorder => $child) {
+                $json .= $this->exportToJSON($child, $tabs."\t\t");
+            }
+            $json = substr($json, 0, strrpos($json, ','));
+            $json .= "\n$tabs\t]\n";
+        } 
+
+        if ($first) {
+            $json .= "\n}";
+        } else {
+            $json .= "\n$tabs},\n";
+        }
+        
+        return $json;
+    }
 }
 
 ?>
diff --git a/grade/report/grader/ajax.php b/grade/report/grader/ajax.php
new file mode 100644
index 0000000000..c289315332
--- /dev/null
+++ b/grade/report/grader/ajax.php
@@ -0,0 +1,582 @@
+<script type="text/javascript">
+//<![CDATA[
+
+// If the mouse is clicked outside this element, the edit is CANCELLED (even if the mouse clicks another grade/feedback cell)
+// If ctrl-arrow is used, or if [tab] or [enter] are pressed, the edit is RECORDED and the row is updated. The previous element returns to normal
+
+YAHOO.namespace("grader_report");
+YAHOO.grader_report.el_being_edited = null;
+YAHOO.grader_report.courseid = <?php echo $COURSE->id; ?>;
+YAHOO.grader_report.wwwroot = '<?php echo $CFG->wwwroot; ?>';
+YAHOO.grader_report.straddfeedback = '<?php echo get_string("addfeedback", "grades"); ?>';
+YAHOO.grader_report.strfeedback = '<?php echo get_string("feedback", "grades"); ?>';
+YAHOO.grader_report.feedback_trunc_length = <?php echo $report->feedback_trunc_length ?>;
+YAHOO.grader_report.decimalpoints = <?php echo $report->getItemsDecimalPoints() ?>;
+YAHOO.grader_report.studentsperpage = <?php echo $report->get_pref('studentsperpage'); ?>;
+YAHOO.grader_report.showquickfeedback = <?php echo $report->get_pref('showquickfeedback'); ?>;
+
+// Feedback data is cached in a JS array: we don't want to show complete feedback strings in the report, but
+// neither do we want to fetch the feedback from PHP each time we click one to edit it
+YAHOO.grader_report.feedbacks = <?php echo $report->getFeedbackJsArray(); ?>
+
+
+/**
+ * Given an elementId formatted as grade[cell|value|feedback]_u[$userId]-i[$itemId], returns an object with key-value pairs
+ * @param string elId
+ * @return object
+ */
+YAHOO.grader_report.getIdData = function(elId) {
+    var re = /grade(value|feedback|cell|scale)_([0-9]*)-i([0-9]*)/;
+    var matches = re.exec(elId);
+    if (undefined != matches && matches.length > 0) {
+        return {type: matches[1], userId: matches[2], itemId: matches[3]};
+    } else {
+        YAHOO.log("getIdData: Invalid elementId: " + elId, "warn");
+        return false;
+    }
+};
+
+/**
+ * Reverse-engineering of getIdData: returns a string based on an object
+ * @param object idData
+ * @return string
+ */
+YAHOO.grader_report.getElementId = function(idData) {
+    if (undefined != idData.userId && undefined != idData.type && undefined != idData.itemId) {
+        return "grade" + idData.type + "_" + idData.userId + "-i" + idData.itemId;
+    } else {
+        YAHOO.log("getElementId: Invalid elementId: " + idData, "warn");
+        return false;
+    }
+};
+
+/**
+ * Interface to the overlib js library. DEPENDENCY ALERT!
+ */
+YAHOO.grader_report.tooltip = function(e, dataObj) {
+    var gr = YAHOO.grader_report;
+    if (undefined != dataObj.text) {
+        return overlib(dataObj.text, BORDER, 0, FGCLASS, 'feedback', CAPTIONFONTCLASS, 'caption', CAPTION, gr.strfeedback);
+    } else {
+        return null;
+    }
+};
+
+/**
+ * Sends the record request and un-edits the element
+ * @param object editedEl The DOM element being edited, whose value we are trying to save in DB
+ * @return array An array of values used to update the row
+ */
+YAHOO.grader_report.saveField = function(editedEl) {
+    var gr = YAHOO.grader_report;
+    var idData = gr.getIdData(editedEl.id);
+    
+    if (idData.type == 'value') { // Text input
+        var newVal = editedEl.firstChild.value;
+    } else if (idData.type == 'feedback') { // Textarea
+        var newVal = editedEl.firstChild.innerHTML;
+    } else if (idData.type == 'scale') { // Select
+        var newVal = editedEl.options[editedEl.selectedIndex].value;
+    }
+    
+    // Don't save if the new value is the same as the old
+    if (gr.el_being_edited.value == newVal || (gr.el_being_edited.value == gr.straddfeedback && newVal == '')) {
+        YAHOO.log("saveField: Field unchanged, not saving. (" + newVal + ")", "info");
+        return false;
+    }
+
+    YAHOO.log("saveField: Old value: " + gr.el_being_edited.value + ", new value: " + newVal + ". Saving field...", "info");
+    
+    var postData = "id=" + gr.courseid + "&userid=" + idData.userId + "&itemid=" + idData.itemId + 
+                   "&action=update&newvalue=" + newVal + "&type=" + idData.type;
+    
+    var handleSuccess = function(o) {
+        try {
+            var queryResult = YAHOO.lang.JSON.parse(o.responseText);
+        } catch (e) {
+            YAHOO.log("saveField: JSON syntax error! " + o.responseText, "error");
+        }
+
+        if (queryResult.result == "success") {
+            // For a textarea, truncate the feedback to 40 chars and provide a tooltip with the full text
+            if (queryResult.gradevalue == null) {
+                if (idData.type == 'scale') {
+                    editedEl.selectedIndex = 0;
+                } else {
+                    editedEl.innerHTML = '';
+                }
+            } else if (idData.type == 'feedback') {
+                editedEl.innerHTML = gr.truncateText(queryResult.gradevalue);
+                
+                YAHOO.util.Event.addListener(editedEl.id, 'mouseover', gr.tooltip, {text: queryResult.gradevalue}, true);
+                YAHOO.util.Event.addListener(editedEl.id, 'mouseout', nd); // See overlib doc for reference
+                gr.feedbacks[idData.userId][idData.itemId] = queryResult.gradevalue;
+            } else if (idData.type == 'value') {
+                editedEl.innerHTML = gr.roundValue(queryResult.gradevalue, idData.itemId);
+            }
+
+            YAHOO.util.Dom.addClass(editedEl, "editable");
+
+            // TODO "highlight" the updated element using animation of color (yellow fade-out)
+            
+            // Update the row's final grade values
+            gr.updateRow(gr.getIdData(editedEl.id).userId, queryResult.row);
+        } else {
+
+        }
+
+        // Display message
+        gr.displayMessage(queryResult.result, queryResult.message, editedEl);
+    }
+
+    var handleFailure = function(o) {
+        YAHOO.log("saveField: Failure to call the ajax callbacks page!", "error");
+    }
+    
+    var uri = gr.wwwroot + '/grade/report/grader/ajax_callbacks.php';
+    var callback = {success: handleSuccess, failure: handleFailure};
+    var conn = YAHOO.util.Connect.asyncRequest("post", uri, callback, postData);
+}; // End of saveField function
+
+/**
+ * Displays a message in the message bar above the report, Google-style
+ * @param string result "success", "notice" or "error"
+ * @param string message
+ * @param object An element to highlight
+ */
+YAHOO.grader_report.displayMessage = function(result, message, elToHighlight) {
+    var messageDiv = document.getElementById('grader_report_message');
+    // Remove previous message
+    // TODO log messages in DB?
+    messageDiv.innerHTML = '';
+
+    if (message.length < 1 || !message) {
+        return false;
+    }
+
+    // Remove all state classes first
+    YAHOO.util.Dom.removeClass(messageDiv, 'success');
+    YAHOO.util.Dom.removeClass(messageDiv, 'error');
+    YAHOO.util.Dom.removeClass(messageDiv, 'notice');
+    
+    var attributes = {backgroundColor: { to: '#00F0F0'} };
+    
+    // Add result class
+    YAHOO.util.Dom.addClass(messageDiv, result);
+    
+    messageDiv.innerHTML = message;
+
+    // Highlight given element
+    if (result == 'error' && elToHighlight != null) {
+        YAHOO.util.Dom.addClass(elToHighlight, 'error');
+    }
+};
+
+/**
+ * Given a userId and an array of string values, updates the innerHTML of each grade cell in the row
+ * @param string userId Identifies the correct row
+ * @param array An array of values
+ *
+ */
+YAHOO.grader_report.updateRow = function(userId, row) {
+    var gr = YAHOO.grader_report;
+
+    // Send update request and update the row
+    YAHOO.log("updateRow: Updating row..." + row, "info");
+    
+    for (var i in row) {
+        if (row[i].finalgrade != null) {
+            // Build id string
+            var gradevalue = gr.roundValue(row[i].finalgrade, row[i].itemid);
+
+            if (row[i].scale) {
+                var idString = "gradescale_";
+            } else {
+                var idString = "gradevalue_";
+            }
+
+            idString += row[i].userid + "-i" + row[i].itemid;
+
+            var elementToUpdate = document.getElementById(idString);
+            
+            if (undefined == elementToUpdate) {
+                YAHOO.log("updateRow: Element with id " + idString + " does not exist!", "error");
+            } else {
+                if (row[i].scale) {
+                    elementToUpdate.selectedIndex = gradevalue;
+                } else {
+                    elementToUpdate.innerHTML = gradevalue;
+                }
+                
+                // Add overridden class where it applies, and remove it where it does not
+                // TODO fix the code below, it doesn't currently work. See ajax_callbacks.php for the code building the JSON data
+                if (row[i].overridden > 0) {
+                    YAHOO.util.Dom.addClass(elementToUpdate.parentNode, "overridden");
+                } else if (YAHOO.util.Dom.hasClass(elementToUpdate.parentNode, "overridden")) {
+                    YAHOO.util.Dom.removeClass(elementToUpdate.parentNode, "overridden");
+                }
+
+                YAHOO.log("updateRow: Updated finalgrade (" + gradevalue + ") of user " + row[i].userid + " for grade item " + row[i].itemid, "info");
+            }
+        }
+    }
+};
+
+/**
+ * Given a gradevalue or gradefeedback <a> element, 
+ * @param object element A DOM element
+ */
+YAHOO.grader_report.openField = function(element) {
+    YAHOO.log("openField: Moving to next item: " + element.id, "info"); 
+    var gr = YAHOO.grader_report; 
+    var idData = gr.getIdData(element.id);
+    element.inputId = element.id + "_input";
+    
+    // If field is in error, empty it before editing
+    if (YAHOO.util.Dom.hasClass(element, 'error')) {
+        if (idData.type == 'feedback') {
+            element.innerHTML = '';
+        } else if (idData.type == 'value') {
+            element.value = '';
+        }
+        
+        YAHOO.util.Dom.removeClass(element, 'error');
+    }
+
+    // Show a textarea for feedback, input for grade and leave scale as it is
+    if (undefined == idData.type) {
+        YAHOO.log("openField: Could not get info from elementId: " + element.id, "warn");
+    } else if (idData.type == 'feedback') {
+        var original = gr.feedbacks[idData.userId][idData.itemId].toString();
+        var tabIndex = element.tabIndex.toString();
+        var displayValue = null;
+
+        // If empty feedback, show empty textarea
+        if (original == gr.straddfeedback) {
+            displayValue = '';
+        } else {
+            displayValue = original;
+        }
+
+        element.innerHTML = '<textarea id="' + element.inputId + '" name="' + idData.type + '">' + displayValue + '</textarea>';
+        setTimeout(function() {element.firstChild.focus(); }, 0); 
+    } else if (idData.type == 'value') {
+        var original = element.innerHTML.toString(); // Removes reference to original
+        element.innerHTML = '<input onfocus="this.select()" id="' + element.inputId + '" type="text" name="' + 
+                            idData.type + '" value="' + gr.roundValue(original, idData.itemId) + '" />';
+        setTimeout(function() {element.firstChild.focus(); }, 0); 
+    } else if (idData.type == 'scale') {
+        var original = element.options[element.selectedIndex].value;
+        setTimeout(function() {element.focus(); }, 0); 
+    }
+    
+    YAHOO.util.Dom.removeClass(element, "editable");
+    
+    // Save the element and its original value
+    gr.el_being_edited = {elementId: element.id, value: original, tabIndex: tabIndex};
+    YAHOO.log("openField: el_being_edited saved as: " + gr.el_being_edited.value, "info");
+}
+
+/**
+ * Replaces the input, textarea or select inside a gradecell with the value currently held in that
+ * input, textarea or select. If the second argument (cancel) is true, replaces the innerHTML with
+ * the value held in YAHOO.grader_report.el_being_edited
+ *
+ * @param object  element DOM element being closed
+ * @param boolean forcecancel If true, current value held in input element is dropped in favour of original value in memory
+ */
+YAHOO.grader_report.closeField = function(element, forcecancel) {
+    YAHOO.log("closeField: Closing field: " + element.id, "info");
+
+    var gr = YAHOO.grader_report;
+    var idData = gr.getIdData(element.id);
+
+    if (idData.type == 'feedback') {
+        var newValue = element.firstChild.value;
+        var originalValue = gr.feedbacks[idData.userId][idData.itemId];
+        
+        if (!forcecancel && originalValue == newValue) {
+            YAHOO.log("closeField: originalValue == newvalue, forcing a cancel", "info");
+            forcecancel = true;
+            originalValue = gr.truncateText(originalValue);
+        }
+    } else if (idData.type == 'value') {
+        var originalValue = gr.el_being_edited.value;
+        var newValue = element.firstChild.value;
+    } 
+    
+    YAHOO.util.Dom.addClass(element, "editable");
+    
+    // No need to change HTML for select element
+    if (idData.type == 'scale') {
+        gr.el_being_edited = null;
+        return;
+    }
+    
+    if (forcecancel || ((newValue == '' && idData.type == 'feedback') && idData.type != 'scale')) {
+        // Replace the input by the original value as plain text
+        element.innerHTML = gr.truncateText(originalValue);
+        YAHOO.log("closeField: Cancelling : Replacing field by original value: " + originalValue, "info");
+    } else {
+        // For numeric grades, round off to item decimal points
+        if (idData.type == 'value') {
+            element.innerHTML = gr.roundValue(newValue, idData.itemId); 
+        } else if (idData.type == 'feedback') {
+            element.innerHTML = newValue;
+        }
+    }
+
+    // Erase the element in memory
+    gr.el_being_edited = null;
+};
+
+/**
+ * Given a string, truncates it if over the limit defined in the report's preferences, adding an ellipsis at the end.
+ * TODO improve the regex so that it doesn't truncate halfway through a word
+ * @param string text
+ * @return string
+ */
+YAHOO.grader_report.truncateText = function(text) {
+    var gr = YAHOO.grader_report;
+    var returnString = '';
+
+    returnString = text.substring(0, gr.feedback_trunc_length); 
+    
+    // Add ... if the string was truncated
+    if (returnString.length < text.length) { 
+        returnString += '...';
+    }
+
+    return returnString;
+}
+
+/**
+ * Given a float value and an itemId, uses that grade_item's decimalpoints preference to round off the value and return it.
+ * @param float value
+ * @param int itemId
+ * @return string
+ */
+YAHOO.grader_report.roundValue = function(value, itemId) {
+    return value;
+
+    // I am ignoring the rest for now, because I am not sure we should round values while in editing mode
+    if (value.length == 0) {
+        return '';
+    }
+
+    var gr = YAHOO.grader_report;
+    var decimalpoints = gr.decimalpoints[itemId];
+    var gradevalue = Math.round(Number(value) * Math.pow(10, decimalpoints)) / Math.pow(10, decimalpoints);
+
+    // If the value is an integer, add appropriate zeros after the decimal point
+    if (gradevalue % 1 == 0 && decimalpoints > 0) {
+        gradevalue += '.';
+        for (var i = 0; i < decimalpoints; i++) {
+            gradevalue += '0';
+        }
+    }
+
+    return gradevalue; 
+};
+
+/**
+ * Given an element of origin, returns the field to be edited in the given direction.
+ * @param object origin_element
+ * @param string direction previous|next|left|right|up|down
+ * @return object element
+ */
+YAHOO.grader_report.getField = function(origin_element, direction) {
+    var gr = YAHOO.grader_report;
+    // get all 'editable' elements
+    var haystack = YAHOO.util.Dom.getElementsByClassName('editable');
+    var wrapElement = null;
+    
+    var feedbackModifier = 1;
+    var upDownOffset = 1;
+    var idData = gr.getIdData(origin_element.id);
+
+    if (gr.showquickfeedback) {
+        feedbackModifier = 2;
+        
+        if (idData.type == 'value' || idData.type == 'scale') {
+            upDownOffset = gr.studentsperpage;
+        }
+
+    }
+
+    if (direction == 'next') {
+        var wrapValue = 1;
+        var needle = origin_element.tabIndex + 1;
+    
+    } else if (direction == 'previous') {
+        var wrapValue = haystack.length;
+        var needle = origin_element.tabIndex - 1;
+    
+    } else if (direction == 'right') {
+        var needle = origin_element.tabIndex + gr.studentsperpage * feedbackModifier;
+        var wrapValue = null; // TODO implement wrapping when moving right
+    
+    } else if (direction == 'left') {
+        var needle = origin_element.tabIndex - gr.studentsperpage * feedbackModifier;
+        var wrapValue = null; // TODO implement wrapping when moving left
+    
+    } else if (direction == 'up') {
+        
+        // Jump up from value to feedback: origin + (studentsperpage - 1)
+        if (idData.type == 'value' || idData.type == 'scale') {
+            var upDownOffset = gr.studentsperpage - 1;
+        
+        // Jump up from feedback to value: origin - studentsperpage
+        } else if (idData.type == 'feedback') {
+            var upDownOffset = -(gr.studentsperpage);
+        }
+
+        var needle = origin_element.tabIndex + upDownOffset;
+        var wrapValue = haystack.length;
+    
+    } else if (direction == 'down') {
+        // Jump down from value to feedback: origin + studentsperpage
+        if (idData.type == 'value' || idData.type == 'scale') {
+            var upDownOffset = gr.studentsperpage;
+
+        // Jump down from feedback to value: origin - (studentsperpage - 1)
+        } else if (idData.type == 'feedback') {
+            var upDownOffset = -(gr.studentsperpage - 1);
+        }    
+        var needle = origin_element.tabIndex + upDownOffset;
+        var wrapValue = 1;
+    }  
+
+    for (var i = 0; i < haystack.length; i++) {
+        if (haystack[i].tabIndex == wrapValue) {
+            wrapElement = haystack[i];
+        }
+
+        if (haystack[i].tabIndex == needle) {
+            return haystack[i];
+        } 
+    }
+
+    // If we haven't returned yet, it means we have reached the end of tabindices: return the wrap element
+    if (wrapElement != null) {
+        return wrapElement;
+    } else { // If no wrap element, just return the element of origin: we are stuck!
+        return origin_element;
+    }
+};
+
+
+YAHOO.grader_report.init = function() {
+    var gr = YAHOO.grader_report;
+
+    // Handle Key presses: Tab and Enter
+    this.keyHandler = function(e) {
+        var charCode = YAHOO.util.Event.getCharCode(e);
+        
+        YAHOO.log("init: Key pressed (" + charCode + "). el_being_edited = " + gr.el_being_edited, "info");
+        // Handle keys if editing
+        if (gr.el_being_edited !== null) {
+            var editedEl = document.getElementById(gr.el_being_edited.elementId);
+            var idData = gr.getIdData(editedEl.id);
+            
+            // Handle Tab and Shift-Tab for navigation forward/backward
+            if (charCode == 9) {
+                gr.saveField(editedEl);
+                gr.closeField(editedEl, false);
+
+                if (e.shiftKey) {
+                    var fieldToOpen = gr.getField(editedEl, 'previous'); 
+                } else {
+                    var fieldToOpen = gr.getField(editedEl, 'next'); 
+                }
+                
+                gr.openField(fieldToOpen);
+            }
+            
+            // Handle Enter key press
+            if (charCode == 13 && idData.type != 'feedback') { // textareas need [enter]
+                // Locate element being edited
+                var editedEl = document.getElementById(gr.el_being_edited.elementId);
+                gr.saveField(editedEl);
+                gr.closeField(editedEl, false);
+            }
+
+            // Handle ctrl-arrows
+            var arrows = { 37: "left", 38: "up", 39: "right", 40: "down" };
+            
+            if (e.ctrlKey && (charCode == 37 || charCode == 38 || charCode == 39 || charCode == 40)) {
+                gr.saveField(editedEl);
+                gr.closeField(editedEl, false);
+                
+                var fieldToOpen = gr.getField(editedEl, arrows[charCode]);
+                gr.openField(fieldToOpen);
+            }
+        }
+    }
+    
+    // Handle mouse clicks
+    this.clickHandler = function(e) {
+        var clickTargetElement = YAHOO.util.Event.getTarget(e);
+
+        
+        // Handle a click while a grade value or feedback is being edited
+        if (gr.el_being_edited !== null) {
+            // idData represents the element being edited, not the clicked element
+            var idData = gr.getIdData(gr.el_being_edited.elementId);
+            
+            if (idData.type != 'scale') { 
+                // If clicking in a cell being edited, no action
+                // parentNode is the original a to which the element was added as a Child node
+                if (gr.el_being_edited.elementId == clickTargetElement.parentNode.id) {
+                    YAHOO.log("init: Clicked within the edited element, no action.", "info");
+                    return false;
+                }
+                
+                // Otherwise, we CANCEL the current edit
+                var originalTarget = document.getElementById(gr.el_being_edited.elementId);
+                YAHOO.log("init: Clicked out of the edited element, cancelling edit.", "info");
+                gr.closeField(originalTarget, true);
+            
+            } else if (idData.type == 'scale' && gr.el_being_edited.elementId == clickTargetElement.id) {
+                
+                // An option has been selected, update the element
+                gr.saveField(clickTargetElement);
+                // Then open the element to save the new value in el_being_edited
+                gr.openField(clickTargetElement);
+                return;
+            }
+        }
+
+        while (clickTargetElement.id != 'grade-report-grader-index') {
+            anchor_re = /(gradevalue|gradefeedback|gradescale)(.*) editable/;
+            anchor_matches = anchor_re.exec(clickTargetElement.className);
+            
+            // YAHOO.log("className = " + clickTargetElement.className, "info");
+            var nodeName = clickTargetElement.nodeName.toLowerCase();
+
+            if ((nodeName == 'a' || nodeName == 'select') && anchor_matches) {
+                gr.openField(clickTargetElement);
+                break;
+
+            // If clicked anywhere else in the cell, default to editing the grade, not the feedback    
+            } else if (clickTargetElement.nodeName.toLowerCase() == "td" && clickTargetElement.id.match(/gradecell/)) {
+                anchors = YAHOO.util.Dom.getElementsByClassName("editable", "a", clickTargetElement);
+                if (anchors.length > 0) {
+                    clickTargetElement = anchors[0];
+                } else {
+                    break;
+                }
+            } else {
+                clickTargetElement = clickTargetElement.parentNode;
+            }
+        }
+    }
+
+    YAHOO.util.Event.on("grade-report-grader-index", "click", this.clickHandler);
+    YAHOO.util.Event.on(document, "keydown", this.keyHandler, this, true);
+};
+
+YAHOO.util.Event.onDOMReady(YAHOO.grader_report.init);
+
+// ]]>
+</script>
diff --git a/grade/report/grader/ajax_callbacks.php b/grade/report/grader/ajax_callbacks.php
new file mode 100644
index 0000000000..c221628da9
--- /dev/null
+++ b/grade/report/grader/ajax_callbacks.php
@@ -0,0 +1,139 @@
+<?php // $Id$
+
+///////////////////////////////////////////////////////////////////////////
+// NOTICE OF COPYRIGHT                                                   //
+//                                                                       //
+// Moodle - Modular Object-Oriented Dynamic Learning Environment         //
+//          http://moodle.org                                            //
+//                                                                       //
+// Copyright (C) 1999 onwards  Martin Dougiamas  http://moodle.com       //
+//                                                                       //
+// This program 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 2 of the License, or     //
+// (at your option) any later version.                                   //
+//                                                                       //
+// This program 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:                          //
+//                                                                       //
+//          http://www.gnu.org/copyleft/gpl.html                         //
+//                                                                       //
+///////////////////////////////////////////////////////////////////////////
+
+
+require_once '../../../config.php'; 
+require_once $CFG->libdir.'/gradelib.php';
+require_once $CFG->dirroot.'/grade/lib.php';
+// require_once $CFG->dirroot.'/grade/report/grader/ajaxlib.php';
+// require_once $CFG->dirroot.'/grade/report/grader/lib.php';
+
+$courseid = required_param('id');                   // course id
+$userid = optional_param('userid', false, PARAM_INT);
+$itemid = optional_param('itemid', false, PARAM_INT);
+$type = optional_param('type', false, PARAM_ALPHA);
+$action = optional_param('action', false, PARAM_ALPHA);
+$newvalue = optional_param('newvalue', false, PARAM_MULTILANG);
+
+switch ($action) {
+    case 'update':
+        if (!empty($userid) && !empty($itemid) && $newvalue !== false && !empty($type)) {
+            // Save the grade or feedback
+            if (!$grade_item = grade_item::fetch(array('id'=>$itemid, 'courseid'=>$courseid))) { // we must verify course id here!
+                print_error('Incorrect grade item id');
+            }
+            
+            /**
+             * Code copied from grade/report/grader/lib.php line 187+
+             */
+            $warnings = array();
+            $finalvalue = null;
+            $finalgrade = null;
+            $feedback = null;
+            $json_object = new stdClass();
+            // Pre-process grade
+            if ($type == 'value' || $type == 'scale') {
+                $feedback = false;
+                $feedbackformat = false;
+                if ($grade_item->gradetype == GRADE_TYPE_SCALE) {
+                    if ($newvalue == -1) { // -1 means no grade
+                        $finalgrade = null;
+                    } else {
+                        $finalgrade = $newvalue;
+                    }
+                } else {
+                    $finalgrade = unformat_float($newvalue);
+                }
+
+                $errorstr = '';
+                // Warn if the grade is out of bounds.
+                if (is_null($finalgrade)) {
+                    // ok
+                } else if ($finalgrade < $grade_item->grademin) {
+                    $errorstr = 'lessthanmin';
+                } else if ($finalgrade > $grade_item->grademax) {
+                    $errorstr = 'morethanmax';
+                }
+
+                if ($errorstr) {
+                    $user = get_record('user', 'id', $userid, '', '', '', '', 'id, firstname, lastname');
+                    $gradestr = new object();
+                    $gradestr->username = fullname($user);
+                    $gradestr->itemname = $grade_item->get_name();
+                    $json_object->message = get_string($errorstr, 'grades', $gradestr);
+                    $json_object->result = "error";
+                    
+                }
+
+                $finalvalue = $finalgrade;
+
+            } else if ($type == 'feedback') {
+                $finalgrade = false;
+                $trimmed = trim($newvalue);
+                if (empty($trimmed)) {
+                    $feedback = NULL;
+                } else {
+                    $feedback = stripslashes($newvalue);
+                }
+
+                $finalvalue = $feedback;
+            }
+            
+            if (!empty($json_object->result) && $json_object->result == 'error') {
+                echo json_encode($json_object);
+                die();
+            } else {
+                $json_object->gradevalue = $finalvalue;
+            
+                if ($grade_item->update_final_grade($userid, $finalgrade, 'gradebook', $feedback, FORMAT_MOODLE)) {
+                    $json_object->result = 'success';
+                    $json_object->message = false;
+                } else {
+                    $json_object->result = 'error';
+                    $json_object->message = "TO BE LOCALISED: Failure to update final grade!";
+                    echo json_encode();
+                    die();
+                }
+                
+                // Get row data
+                $sql = "SELECT gg.id, gi.id AS itemid, gi.scaleid AS scale, gg.userid AS userid, finalgrade, gg.overridden AS overridden "
+                     . "FROM {$CFG->prefix}grade_grades gg, {$CFG->prefix}grade_items gi WHERE " 
+                     . "gi.courseid = $courseid AND gg.itemid = gi.id AND gg.userid = $userid";
+                $records = get_records_sql($sql);
+                $json_object->row = $records;
+                echo json_encode($json_object);
+                die();
+            }
+        } else {
+            $json_object = new stdClass();
+            $json_object->result = "error";
+            $json_object->message = "Missing parameter to ajax UPDATE callback: \n" . 
+                                    "  userid: $userid,\n  itemid: $itemid\n,  type: $type\n,  newvalue: $newvalue";
+            echo json_encode($json_object);
+        }
+
+        break;
+}
+
+?>
diff --git a/grade/report/grader/ajaxlib.php b/grade/report/grader/ajaxlib.php
new file mode 100644
index 0000000000..47358a1614
--- /dev/null
+++ b/grade/report/grader/ajaxlib.php
@@ -0,0 +1,527 @@
+<?php // $Id$
+
+///////////////////////////////////////////////////////////////////////////
+//                                                                       //
+// NOTICE OF COPYRIGHT                                                   //
+//                                                                       //
+// Moodle - Modular Object-Oriented Dynamic Learning Environment         //
+//          http://moodle.com                                            //
+//                                                                       //
+// Copyright (C) 1999 onwards Martin Dougiamas  http://dougiamas.com     //
+//                                                                       //
+// This program 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 2 of the License, or     //
+// (at your option) any later version.                                   //
+//                                                                       //
+// This program 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:                          //
+//                                                                       //
+//          http://www.gnu.org/copyleft/gpl.html                         //
+//                                                                       //
+///////////////////////////////////////////////////////////////////////////
+/**
+ * File in which the grade_report_grader class is defined.
+ * @package gradebook
+ */
+
+require_once($CFG->dirroot . '/grade/report/grader/lib.php');
+
+/**
+ * Class providing an API for the grader report building and displaying.
+ * @uses grade_report
+ * @package gradebook
+ */
+class grade_report_grader_ajax extends grade_report_grader {
+    
+    /**
+     * An array of feedbacks, indexed by userid_itemid, used for JS caching
+     * @var array $feedbacks
+     */
+    var $feedbacks = array();
+    
+    /**
+     * Length at which feedback will be truncated (to the nearest word) and an ellipsis be added.
+     * TODO replace this by a report preference
+     * @var int $feedback_trunc_length
+     */
+    var $feedback_trunc_length = 50;
+    
+    /**
+     * Self-incrementing variable, tracking the tabindex. Depending on the tabindex option ("all values, then feedbacks" is default)
+     * Increments by one between each user for the gradevalues, and by 1 + usercount for the gradefeedback
+     * @var int $tabindex
+     */
+    var $tabindex = 0;
+
+    /**
+     * Constructor. Sets local copies of user preferences and initialises grade_tree.
+     * @param int $courseid
+     * @param object $gpr grade plugin return tracking object
+     * @param string $context
+     * @param int $page The current page being viewed (when report is paged)
+     * @param int $sortitemid The id of the grade_item by which to sort the table
+     */
+    function grade_report_grader_ajax($courseid, $gpr, $context, $page=null, $sortitemid=null) {
+        parent::grade_report_grader($courseid, $gpr, $context, $page, $sortitemid);
+    }
+    
+    /**
+     * Loads, stores and returns the array of scales used in this course.
+     * @return array
+     */
+    function get_scales_array() {
+        if (empty($this->gtree->items)) {
+            return false;
+        }
+        
+        if (!empty($this->scales_array)) {
+            return $this->scales_array;
+        }
+
+        $scales_list = '';
+        $scales_array = array();
+        
+        foreach ($this->gtree->items as $item) {
+            if (!empty($item->scaleid)) {
+                $scales_list .= "$item->scaleid,";
+            }
+        }
+        
+        if (!empty($scales_list)) {
+            $scales_list = substr($scales_list, 0, -1);
+            $scales_array = get_records_list('scale', 'id', $scales_list);
+            $this->scales_array = $scales_array;
+            return $scales_array;
+        } else {
+            return null;
+        }
+    }
+    
+    /**
+     * Processes the data sent by the form (grades and feedbacks).
+     * Caller is responsible for all access control checks
+     * @param array $data form submission (with magic quotes)
+     * @return array empty array if success, array of warnings if something fails.
+     */
+    function process_data($data) {
+        return parent::process_data($data);
+    }
+
+    /**
+     * Builds and returns a div with on/off toggles.
+     * @return string HTML code
+     */
+    function get_toggles_html() {
+        return parent::get_toggles_html();
+    }
+
+    /**
+     * Shortcut function for printing the grader report toggles.
+     * @param string $type The type of toggle
+     * @param bool $return Whether to return the HTML string rather than printing it
+     * @return void
+     */
+    function print_toggle($type, $return=false) {
+        return parent::print_toggle($type, $return);
+    }
+
+    /**
+     * Builds and returns the HTML code for the headers.
+     * @return string $headerhtml
+     */
+    function get_headerhtml() {
+        return parent::get_headerhtml();
+    }
+
+    /**
+     * Builds and return the HTML rows of the table (grades headed by student).
+     * @return string HTML
+     */
+    function get_studentshtml() {
+        if (empty($this->users)) {
+            print_error('nousersloaded', 'grades');
+        }
+        
+        $this->numusers = count($this->users);
+
+        $studentshtml = ''; 
+
+        foreach ($this->users as $userid => $user) {
+            $this->tabindex++;
+            $studentshtml .= $this->get_studentrowhtml($user);
+        }
+
+        return $studentshtml;
+    }
+    
+    
+    /**
+     * Given a userid, and provided the gtree is correctly loaded, returns a complete HTML row for this user.
+     *
+     * @param object $user
+     * @return string
+     */
+    function get_studentrowhtml($user) {
+        global $CFG;
+        $showuserimage = $this->get_pref('showuserimage');
+        $showuseridnumber = $this->get_pref('showuseridnumber');
+        $studentrowhtml = '';
+        $row_classes = array(' even ', ' odd ');
+
+        if ($this->canviewhidden) {
+            $altered = array();
+            $unknown = array();
+        } else {
+            $hiding_affected = grade_grade::get_hiding_affected($this->grades[$userid], $this->gtree->items);
+            $altered = $hiding_affected['altered'];
+            $unknown = $hiding_affected['unknown'];
+            unset($hiding_affected);
+        }
+
+        $columncount = 0;
+        // Student name and link
+        $user_pic = null;
+        if ($showuserimage) {
+            $user_pic = '<div class="userpic">' . print_user_picture($user, $this->courseid, true, 0, true) . '</div>';
+        }
+
+        $studentrowhtml .= '<tr class="r'.$this->rowcount++ . $row_classes[$this->rowcount % 2] . '">'
+                      .'<th class="header c'.$columncount++.' user" scope="row" onclick="set_row(this.parentNode.rowIndex);">'.$user_pic
+                      .'<a href="'.$CFG->wwwroot.'/user/view.php?id='.$user->id.'&amp;course='.$this->course->id.'">'
+                      .fullname($user).'</a></th>';
+
+        if ($showuseridnumber) {
+            $studentrowhtml .= '<th class="header c'.$columncount++.' useridnumber" onclick="set_row(this.parentNode.rowIndex);">'. $user->idnumber.'</th>';
+        }
+        
+        $columntabcount = 0;
+        $feedback_tabindex_modifier = 1; // Used to offset the grade value at the beginning of each new column
+
+        if ($this->get_pref('showquickfeedback')) {
+            $feedback_tabindex_modifier = 2; 
+        }
+
+        foreach ($this->gtree->items as $itemid=>$unused) {
+
+            $nexttabindex = $this->tabindex + $columntabcount * $feedback_tabindex_modifier * $this->numusers;
+            $studentrowhtml .= $this->get_gradecellhtml($user, $itemid, $columncount, $nexttabindex, $altered, $unknown);
+            $columntabcount++;
+        }
+
+        $studentrowhtml .= '</tr>';
+        return $studentrowhtml;
+
+    }
+    
+    /**
+     * Retuns the HTML table cell for a user's grade for a grade_item
+     *
+     * @param object $user
+     * @param int    $itemid
+     * @param int    $columncount
+     * @param int    $nexttabindex
+     * @param array  $altered
+     * @param array  $unknown
+     *
+     * @return string
+     */
+    function get_gradecellhtml($user, $itemid, $columncount, $nexttabindex, $altered=array(), $unknown=array()) {
+        global $CFG, $USER;
+        
+        $strfeedback  = $this->get_lang_string("feedback");
+        $strgrade     = $this->get_lang_string('grade');
+        
+        // Preload scale objects for items with a scaleid
+        $scales_array = $this->get_scales_array();
+
+        $userid = $user->id;
+        $item =& $this->gtree->items[$itemid];
+        $grade = $this->grades[$userid][$item->id];
+
+        // Get the decimal points preference for this item
+        $decimalpoints = $item->get_decimals();
+
+        if (in_array($itemid, $unknown)) {
+            $gradeval = null;
+        } else if (array_key_exists($itemid, $altered)) {
+            $gradeval = $altered[$itemid];
+        } else {
+            $gradeval = $grade->finalgrade;
+        }
+
+        $gradecellhtml = '';
+
+        // MDL-11274
+        // Hide grades in the grader report if the current grader doesn't have 'moodle/grade:viewhidden'
+        if (!$this->canviewhidden and $grade->is_hidden()) {
+            if (!empty($CFG->grade_hiddenasdate) and $grade->get_datesubmitted() and !$item->is_category_item() and !$item->is_course_item()) {
+                // the problem here is that we do not have the time when grade value was modified, 'timemodified' is general modification date for grade_grades records
+                $gradecellhtml .= '<td class="cell c'.$columncount++.'"><span class="datesubmitted">'.userdate($grade->get_datesubmitted(),get_string('strftimedatetimeshort')).'</span></td>';
+            } else {
+                $gradecellhtml .= '<td class="cell c'.$columncount++.'">-</td>';
+            }
+            continue;
+        }
+
+        // emulate grade element
+        $eid = $this->gtree->get_grade_eid($grade);
+        $element = array('eid'=>$eid, 'object'=>$grade, 'type'=>'grade');
+
+        $cellclasses = 'cell c'.$columncount++;
+        if ($item->is_category_item()) {
+            $cellclasses .= ' cat';
+        }
+        if ($item->is_course_item()) {
+            $cellclasses .= ' course';
+        }
+        if ($grade->is_overridden()) {
+            $cellclasses .= ' overridden';
+        }
+
+        if ($grade->is_excluded()) {
+            $cellclasses .= ' excluded';
+        }
+
+        $gradecellhtml .= "<td id=\"gradecell_u$userid-i$itemid\" class=\"$cellclasses\">";
+
+        if ($grade->is_excluded()) {
+            $gradecellhtml .= get_string('excluded', 'grades') . ' ';
+        }
+
+        // Do not show any icons if no grade (no record in DB to match)
+        if (!$item->needsupdate and $USER->gradeediting[$this->courseid]) {
+            $gradecellhtml .= $this->get_icons($element);
+        }
+
+        $hidden = '';
+        if ($grade->is_hidden()) {
+            $hidden = ' hidden ';
+        }
+
+        $gradepass = ' gradefail '; 
+        if ($grade->is_passed($item)) {
+            $gradepass = ' gradepass ';
+        } elseif (is_null($grade->is_passed($item))) {
+            $gradepass = '';
+        }
+
+        // if in editting mode, we need to print either a text box
+        // or a drop down (for scales)
+        // grades in item of type grade category or course are not directly editable
+        if ($item->needsupdate) {
+            $gradecellhtml .= '<span class="gradingerror'.$hidden.'">'.get_string('error').'</span>';
+
+        } else if ($USER->gradeediting[$this->courseid]) {
+            $anchor_id = "gradevalue_$userid-i$itemid";
+
+            if ($item->scaleid && !empty($scales_array[$item->scaleid])) {
+                $scale = $scales_array[$item->scaleid];
+                $gradeval = (int)$gradeval; // scales use only integers
+                $scales = explode(",", $scale->scale);
+                // reindex because scale is off 1
+
+                // MDL-12104 some previous scales might have taken up part of the array
+                // so this needs to be reset
+                $scaleopt = array();
+                $i = 0;
+                foreach ($scales as $scaleoption) {
+                    $i++;
+                    $scaleopt[$i] = $scaleoption;
+                }
+
+                if ($this->get_pref('quickgrading') and $grade->is_editable()) {
+                    $oldval = empty($gradeval) ? -1 : $gradeval;
+                    if (empty($item->outcomeid)) {
+                        $nogradestr = $this->get_lang_string('nograde');
+                    } else {
+                        $nogradestr = $this->get_lang_string('nooutcome', 'grades');
+                    }
+
+                    $gradecellhtml .= '<select name="grade_'.$userid.'_'.$item->id.'" class="gradescale editable" ' 
+                                    . 'id="gradescale_'.$userid.'-i'.$item->id.'" tabindex="'.$nexttabindex.'">' . "\n";
+                    $gradecellhtml .= '<option value="-1">' . $nogradestr . "</option>\n";
+
+                    foreach ($scaleopt as $val => $label) {
+                        $selected = '';
+                        
+                        if ($val == $oldval) {
+                            $selected = 'selected="selected"';
+                        }
+
+                        $gradecellhtml .= "<option value=\"$val\" $selected>$label</option>\n";
+                    }
+
+                    $gradecellhtml .= "</select>\n";
+
+                } elseif(!empty($scale)) {
+                    $scales = explode(",", $scale->scale);
+
+                    // invalid grade if gradeval < 1
+                    if ($gradeval < 1) {
+                        $gradecellhtml .= '<a tabindex="'.$nexttabindex .'" id="' . $anchor_id 
+                                       . '"  class="gradevalue'.$hidden.$gradepass.'">-</a>';
+                    } else {
+                        //just in case somebody changes scale
+                        $gradeval = (int)bounded_number($grade->grade_item->grademin, $gradeval, $grade->grade_item->grademax); 
+                        $gradecellhtml .= '<a tabindex="'.$nexttabindex .'" id="' . $anchor_id
+                                       . '"  class="gradevalue'.$hidden.$gradepass.'">'.$scales[$gradeval-1].'</a>';
+                    }
+                } else {
+                    // no such scale, throw error?
+                }
+
+            } else if ($item->gradetype != GRADE_TYPE_TEXT) { // Value type
+                $value = $gradeval;
+                if ($this->get_pref('quickgrading') and $grade->is_editable()) {
+                    $gradecellhtml .= '<a tabindex="'.$nexttabindex .'" id="' . $anchor_id 
+                                   . '"  class="gradevalue'.$hidden.$gradepass.' editable">' .$value.'</a>';
+                } else {
+                    $gradecellhtml .= '<a tabindex="'.$nexttabindex .'" id="' . $anchor_id . '"  class="gradevalue'
+                                   .$hidden.$gradepass.'">'.$value.'</a>';
+                }
+            }
+
+
+            // If quickfeedback is on, print an input element
+            if ($this->get_pref('showquickfeedback') and $grade->is_editable()) {
+                if ($this->get_pref('quickgrading')) {
+                    $gradecellhtml .= '<br />';
+                }
+                $feedback = s($grade->feedback);
+                $anchor_id = "gradefeedback_$userid-i$itemid";
+                
+                if (empty($feedback)) {
+                    $feedback = get_string('addfeedback', 'grades');
+                    $gradecellhtml .= '<a ';
+                } else {
+                    $overlib = '';
+                    $full_feedback = addslashes_js(trim(format_string($grade->feedback, $grade->feedbackformat)));
+                    $overlib = "return overlib('$full_feedback', BORDER, 0, FGCLASS, 'feedback', "
+                              ."CAPTIONFONTCLASS, 'caption', CAPTION, '$strfeedback');";
+                    $gradecellhtml .= '<a onmouseover="'.s($overlib).'" onmouseout="return nd();" ';
+                }
+                
+                $feedback_tabindex = $nexttabindex + $this->numusers;
+
+                $short_feedback = shorten_text($feedback, $this->feedback_trunc_length);
+                $gradecellhtml .= ' tabindex="'.$feedback_tabindex .'" id="'
+                               . $anchor_id . '"  class="gradefeedback editable">' . $short_feedback . '</a>';
+                $this->feedbacks[$userid][$item->id] = $feedback;
+            }
+
+        } else { // Not editing
+            $gradedisplaytype = $item->get_displaytype();
+
+            // If feedback present, surround grade with feedback tooltip: Open span here
+            if (!empty($grade->feedback)) {
+                $overlib = '';
+                $feedback = addslashes_js(trim(format_string($grade->feedback, $grade->feedbackformat)));
+                $overlib = "return overlib('$feedback', BORDER, 0, FGCLASS, 'feedback', "
+                          ."CAPTIONFONTCLASS, 'caption', CAPTION, '$strfeedback');";
+                $gradecellhtml .= '<span onmouseover="'.s($overlib).'" onmouseout="return nd();">';
+            }
+
+            if ($item->needsupdate) {
+                $gradecellhtml .= '<span class="gradingerror'.$hidden.$gradepass.'">'.get_string('error').'</span>';
+
+            } else {
+                $gradecellhtml .= '<span class="gradevalue'.$hidden.$gradepass.'">'.grade_format_gradevalue($gradeval, $item, true, $gradedisplaytype, null).'</span>';
+            }
+
+            // Close feedback span
+            if (!empty($grade->feedback)) {
+                $gradecellhtml .= '</span>';
+            }
+        }
+
+        if (!empty($this->gradeserror[$item->id][$userid])) {
+            $gradecellhtml .= $this->gradeserror[$item->id][$userid];
+        }
+
+        $gradecellhtml .=  '</td>' . "\n";
+        return $gradecellhtml;
+    }
+
+    /**
+     * Builds and return the HTML row of column totals.
+     * @param  bool $grouponly Whether to return only group averages or all averages.
+     * @return string HTML
+     */
+    function get_avghtml($grouponly=false) {
+        return parent::get_avghtml();
+    }
+
+    /**
+     * Builds and return the HTML row of ranges for each column (i.e. range).
+     * @return string HTML
+     */
+    function get_rangehtml() {
+        return parent::get_rangehtml();
+    }
+    
+    /**
+     * Builds and return the HTML row of ranges for each column (i.e. range).
+     * @return string HTML
+     */
+    function get_iconshtml() {
+        return parent::get_iconshtml();
+    }
+
+    /**
+     * Given a grade_category, grade_item or grade_grade, this function
+     * figures out the state of the object and builds then returns a div
+     * with the icons needed for the grader report.
+     *
+     * @param object $object
+     * @return string HTML
+     */
+    function get_icons($element) {
+        return parent::get_icons($element);
+    }
+
+    /**
+     * Given a category element returns collapsing +/- icon if available
+     * @param object $object
+     * @return string HTML
+     */
+    function get_collapsing_icon($element) {
+        return parent::get_collapsing_icon($element);
+    }
+
+    /**
+     * Processes a single action against a category, grade_item or grade.
+     * @param string $target eid ({type}{id}, e.g. c4 for category4)
+     * @param string $action Which action to take (edit, delete etc...)
+     * @return
+     */
+    function process_action($target, $action) {
+        return parent::process_action($target, $action);
+    }
+    
+    /**
+     * Returns a valid JSON object with feedbacks indexed by userid and itemid.
+     * Paging is taken into account: this needs to be reloaded at each new page (not page load, just page of data);
+     */
+    function getFeedbackJsArray() {
+        if (!empty($this->feedbacks)) {
+            return json_encode($this->feedbacks);
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Returns a json_encoded hash of itemid => decimalpoints preferences
+     */
+    function getItemsDecimalPoints() { 
+        $decimals = array();
+        foreach ($this->gtree->items as $itemid=>$item) {
+            $decimals[$itemid] = $item->get_decimals();
+        }
+        return json_encode($decimals);
+    }
+}
+?>
diff --git a/grade/report/grader/index.php b/grade/report/grader/index.php
index 5fe42bf527..0232337a0d 100644
--- a/grade/report/grader/index.php
+++ b/grade/report/grader/index.php
@@ -113,14 +113,40 @@ if (!is_null($toggle) && !empty($toggle_type)) {
 //first make sure we have proper final grades - this must be done before constructing of the grade tree
 grade_regrade_final_grades($courseid);
 
-// Perform actions
+// Perform actions.
 if (!empty($target) && !empty($action) && confirm_sesskey()) {
     grade_report_grader::process_action($target, $action);
 }
 
-// Initialise the grader report object
+$bodytags = '';
 $report = new grade_report_grader($courseid, $gpr, $context, $page, $sortitemid);
 
+// Initialise the grader report object
+if (ajaxenabled() && $report->get_pref('enableajax')) {
+    require_once $CFG->dirroot.'/grade/report/grader/ajaxlib.php';
+    
+    require_js(array('yui_yahoo', 
+                     'yui_dom', 
+                     'yui_event', 
+                     'yui_json', 
+                     'yui_connection', 
+                     'yui_dragdrop',
+                     'yui_animation'));
+
+    if (debugging('', DEBUG_DEVELOPER)) {
+        require_js(array('yui_logger'));
+
+        $bodytags = 'onload = "javascript:
+        show_logger = function() {
+            var logreader = new YAHOO.widget.LogReader();
+            logreader.newestOnTop = false;
+            logreader.setTitle(\'Moodle Debug: YUI Log Console\');
+        };
+        show_logger();
+        "';
+    }
+    $report = new grade_report_grader_ajax($courseid, $gpr, $context, $page, $sortitemid);
+}
 
 /// processing posted grades & feedback here
 if ($data = data_submitted() and confirm_sesskey() and has_capability('moodle/grade:edit', $context)) {
@@ -141,8 +167,7 @@ $numusers = $report->get_numusers();
 $report->load_final_grades();
 
 /// Print header
-print_header_simple($strgrades.': '.$reportname, ': '.$strgrades, $navigation,
-                        '', '', true, $buttons, navmenu($course));
+print_header_simple($strgrades.': '.$reportname, ': '.$strgrades, $navigation, '', '', true, $buttons, navmenu($course), false, $bodytags);
 
 /// Print the plugin selector at the top
 print_grade_plugin_selector($courseid, 'report', 'grader');
@@ -168,17 +193,21 @@ if (!empty($studentsperpage)) {
 
 $reporthtml = '<script src="functions.js" type="text/javascript"></script>';
 
+$reporthtml .= '<div id="grader_report_message"></div>' . "\n";
 $reporthtml .= '<table id="user-grades" class="gradestable flexible boxaligncenter generaltable">';
+$reporthtml .= '<thead>';
 $reporthtml .= $report->get_headerhtml();
 $reporthtml .= $report->get_iconshtml();
 $reporthtml .= $report->get_rangehtml();
-$reporthtml .= $report->get_studentshtml();
+$reporthtml .= "</thead>\n<tfoot>";
 $reporthtml .= $report->get_avghtml(true);
 $reporthtml .= $report->get_avghtml();
-$reporthtml .= "</table>";
+$reporthtml .= "</tfoot>\n<tbody>";
+$reporthtml .= $report->get_studentshtml();
+$reporthtml .= "</tbody>\n</table>";
 
 // print submit button
-if ($USER->gradeediting[$course->id]) {
+if ($USER->gradeediting[$course->id] and !$report->get_pref('enableajax')) {
     echo '<form action="index.php" method="post">';
     echo '<div>';
     echo '<input type="hidden" value="'.$courseid.'" name="id" />';
@@ -189,7 +218,9 @@ if ($USER->gradeediting[$course->id]) {
 echo $reporthtml;
 
 // print submit button
-if ($USER->gradeediting[$course->id] && ($report->get_pref('showquickfeedback') || $report->get_pref('quickgrading'))) {
+if ($USER->gradeediting[$course->id] && ($report->get_pref('showquickfeedback')
+    || 
+    $report->get_pref('quickgrading')) && !$report->get_pref('enableajax')) {
     echo '<div class="submit"><input type="submit" value="'.get_string('update').'" /></div>';
     echo '</div></form>';
 }
@@ -199,6 +230,11 @@ if (!empty($studentsperpage) && $studentsperpage >= 20) {
     print_paging_bar($numusers, $report->page, $studentsperpage, $report->pbarurl);
 }
 
+// Print AJAX code
+if ($report->get_pref('enableajax')) {
+    require_once 'ajax.php';
+}
+
 print_footer($course);
 
 ?>
diff --git a/grade/report/grader/preferences_form.php b/grade/report/grader/preferences_form.php
index 3033f23e1c..a32a63f828 100644
--- a/grade/report/grader/preferences_form.php
+++ b/grade/report/grader/preferences_form.php
@@ -115,7 +115,7 @@ class grader_report_preferences_form extends moodleform {
             $preferences['prefgeneral']['aggregationposition'] = array(GRADE_REPORT_PREFERENCE_DEFAULT => '*default*',
                                                                        GRADE_REPORT_AGGREGATION_POSITION_FIRST => get_string('positionfirst', 'grades'),
                                                                        GRADE_REPORT_AGGREGATION_POSITION_LAST => get_string('positionlast', 'grades'));
-            // $preferences['prefgeneral']['enableajax'] = $checkbox_default;
+            $preferences['prefgeneral']['enableajax'] = $checkbox_default;
 
             $preferences['prefshow']['showuserimage'] = $checkbox_default;
             $preferences['prefshow']['showuseridnumber'] = $checkbox_default;
diff --git a/grade/report/grader/settings.php b/grade/report/grader/settings.php
index e23afc0334..0522779a67 100644
--- a/grade/report/grader/settings.php
+++ b/grade/report/grader/settings.php
@@ -50,8 +50,8 @@ $settings->add(new admin_setting_configselect('grade_report_meanselection', get_
                                           array(GRADE_REPORT_MEAN_ALL => get_string('meanall', 'grades'),
                                                 GRADE_REPORT_MEAN_GRADED => get_string('meangraded', 'grades'))));
 
-// $settings->add(new admin_setting_configcheckbox('grade_report_enableajax', get_string('enableajax', 'grades'),
-//                                            get_string('configenableajax', 'grades'), 0));
+$settings->add(new admin_setting_configcheckbox('grade_report_enableajax', get_string('enableajax', 'grades'),
+                                            get_string('configenableajax', 'grades'), 0));
 
 $settings->add(new admin_setting_configcheckbox('grade_report_showcalculations', get_string('showcalculations', 'grades'),
                                             get_string('configshowcalculations', 'grades'), 0));
diff --git a/lang/en_utf8/grades.php b/lang/en_utf8/grades.php
index 8b22667af4..f5b7688ad0 100644
--- a/lang/en_utf8/grades.php
+++ b/lang/en_utf8/grades.php
@@ -345,6 +345,7 @@ $string['nopublish'] = 'Do not publish';
 $string['noselectedcategories'] = 'no categories were selected.';
 $string['noselecteditems'] = 'no items were selected.';
 $string['notteachererror'] = 'You must be a teacher to use this feature.';
+$string['nousersloaded'] = 'No users loaded';
 $string['numberofgrades'] = 'Number of grades';
 $string['onascaleof'] = ' on a scale of $a->grademin to $a->grademax';
 $string['operations'] = 'Operations';
diff --git a/lib/ajax/ajaxlib.php b/lib/ajax/ajaxlib.php
index 787e5a735b..84f5d7e78b 100644
--- a/lib/ajax/ajaxlib.php
+++ b/lib/ajax/ajaxlib.php
@@ -20,10 +20,13 @@ function ajax_get_lib($libname) {
             'yui_calendar' => '/lib/yui/calendar/calendar-min.js',
             'yui_connection' => '/lib/yui/connection/connection-min.js',
             'yui_container' => '/lib/yui/container/container-min.js',
+            'yui_datasource' => '/lib/yui/datasource/datasource-beta-min.js',
             'yui_dom' => '/lib/yui/dom/dom-min.js',
             'yui_dom-event' => '/lib/yui/yahoo-dom-event/yahoo-dom-event.js',
             'yui_dragdrop' => '/lib/yui/dragdrop/dragdrop-min.js',
+            'yui_ddsend' => '/lib/yui/dragdrop/ddsend.js',
             'yui_event' => '/lib/yui/event/event-min.js',
+            'yui_json' => '/lib/yui/json/json-min.js',
             'yui_logger' => '/lib/yui/logger/logger-min.js',
             'yui_menu' => '/lib/yui/menu/menu-min.js',
             'yui_tabview' => '/lib/yui/tabview/tabview-min.js',
-- 
2.39.5