Allow to download data dump as a CSV file

mentoring/__init__.py

 from .answer import AnswerBlock
-from .dataviewer import MentoringDataViewerBlock
+from .dataexport import MentoringDataExportBlock
 from .quizz import QuizzBlock, QuizzTipBlock
 from .mentoring import MentoringBlock
 from .table import MentoringTableBlock, MentoringTableColumnBlock

mentoring/dataviewer.py → mentoring/dataexport.py

@@ -3,14 +3,13 @@
 # Imports ###########################################################
 
 import logging
-import json
 
 from webob import Response
 from xblock.core import XBlock
 from xblock.fragment import Fragment
 
 from .models import Answer
-from .utils import load_resource, render_template
+from .utils import load_resource, list2csv, render_template
 
 
 # Globals ###########################################################
@@ -20,23 +19,21 @@ log = logging.getLogger(__name__)
 
 # Classes ###########################################################
 
-class MentoringDataViewerBlock(XBlock):
+class MentoringDataExportBlock(XBlock):
     """
-    An XBlock allowing the instructor team to read/export all the student answers
+    An XBlock allowing the instructor team to export all the student answers as a CSV file
     """
 
     def student_view(self, context):
-        html = render_template('templates/html/dataviewer.html', {
+        html = render_template('templates/html/dataexport.html', {
             'self': self,
         })
 
         fragment = Fragment(html)
-        fragment.add_javascript(load_resource('static/js/vendor/jquery.handsontable.full.js'))
-        fragment.add_javascript(load_resource('static/js/dataviewer.js'))
-        fragment.add_css(load_resource('static/css/vendor/jquery.handsontable.full.css'))
-        fragment.add_css(load_resource('static/css/dataviewer.css'))
+        fragment.add_javascript(load_resource('static/js/dataexport.js'))
+        fragment.add_css(load_resource('static/css/dataexport.css'))
 
-        fragment.initialize_js('MentoringDataViewerBlock')
+        fragment.initialize_js('MentoringDataExportBlock')
 
         return fragment
 
@@ -44,22 +41,26 @@ class MentoringDataViewerBlock(XBlock):
         return Fragment(u'Studio view body')
 
     @XBlock.handler
-    def get_data(self, request, suffix=''):
-        response_json = json.dumps({'data': self.get_data_list()})
-        return Response(response_json, content_type='application/json')
+    def download_csv(self, request, suffix=''):
+        response = Response(content_type='text/csv')
+        response.app_iter = self.get_csv()
+        response.content_disposition = 'attachment; filename=course_data.csv'
+        return response
 
-    def get_data_list(self):
+    def get_csv(self):
         answers = Answer.objects.all().order_by('student_id', 'name')
         answers_names = Answer.objects.values_list('name', flat=True).distinct().order_by('name')
 
-        data = [['student_id'] + list(answers_names)]
+        # Header line
+        yield list2csv([u'student_id'] + list(answers_names))
+
         row = []
         cur_student_id = None
         cur_col = None
         for answer in answers:
             if answer.student_id != cur_student_id:
                 if row:
-                    data.append(row)
+                    yield list2csv(row)
                 row = [answer.student_id]
                 cur_student_id = answer.student_id
                 cur_col = 0
@@ -69,9 +70,7 @@ class MentoringDataViewerBlock(XBlock):
             row.append(answer.student_input)
             cur_col += 1
         if row:
-            data.append(row)
-
-        return data
+            yield list2csv(row)
 
     @staticmethod
     def workbench_scenarios():
@@ -79,6 +78,6 @@ class MentoringDataViewerBlock(XBlock):
         Sample scenarios which will be displayed in the workbench
         """
         return [
-            ("Mentoring - Page 999, Intructors data viewer",
-                                    load_resource('templates/xml/999_dataviewer.xml')),
+            ("Mentoring - Page 999, Intructors data export",
+                                    load_resource('templates/xml/999_dataexport.xml')),
         ]

mentoring/utils.py

@@ -6,7 +6,9 @@
 import logging
 import os
 import pkg_resources
+import unicodecsv
 
+from cStringIO import StringIO
 from django.template import Context, Template
 from xblock.fragment import Fragment
 
@@ -34,6 +36,16 @@ def render_template(template_path, context={}):
     template = Template(template_str)
     return template.render(Context(context))
 
+def list2csv(row):
+    """
+    Convert a list to a CSV string (single row)
+    """
+    f = StringIO()
+    writer = unicodecsv.writer(f, encoding='utf-8')
+    writer.writerow(row)
+    f.seek(0)
+    return f.read()
+
 
 # Classes ###########################################################
 

requirements.txt

 -e .
+unicodecsv==0.9.4

setup.py

@@ -2,7 +2,7 @@ from setuptools import setup
 
 BLOCKS = [
     'mentoring = mentoring:MentoringBlock',
-    'mentoring-dataviewer = mentoring:MentoringDataViewerBlock',
+    'mentoring-dataexport = mentoring:MentoringDataExportBlock',
     'mentoring-table = mentoring:MentoringTableBlock',
     'column = mentoring:MentoringTableColumnBlock',
     'answer = mentoring:AnswerBlock',

static/css/dataviewer.css → static/css/dataexport.css

-.mentoring-dataviewer .mentoring-dataviewer-table {
-    overflow: scroll;
+.mentoring-dataexport {
     margin: 10px;
 }

static/js/dataexport.js

+function MentoringDataExportBlock(runtime, element) {
+    var downloadUrl = runtime.handlerUrl(element, 'download_csv');
+
+    $('button.download', element).click(function(ev) {
+        ev.preventDefault();
+        window.location = downloadUrl;
+    });
+}

static/js/dataviewer.js

-function MentoringDataViewerBlock(runtime, element) {
-    var handlerUrl = runtime.handlerUrl(element, 'get_data');
-
-    $.get(handlerUrl, function(result) {
-        $('.mentoring-dataviewer .mentoring-dataviewer-table', element).handsontable({
-            data: result.data,
-            colWidths: 300,
-            rowHeaders: true,
-            colHeaders: true,
-            stretchH: 'all'
-        });
-    }, 'json');
-}

templates/html/dataexport.html

+<div class="mentoring-dataexport">
+  <h3>Answers data dump</h3>
+  <button class="download">Download CSV</button>
+</div>

templates/html/dataviewer.html

-<div class="mentoring-dataviewer">
-  <div class="mentoring-dataviewer-table"></div>
-</div>

templates/xml/999_dataexport.xml

+<vertical>
+    <mentoring-dataexport></mentoring-dataexport>
+</vertical>

templates/xml/999_dataviewer.xml

-<vertical>
-    <html>
-        <h3>Answers data</h3>
-    </html>
-    <mentoring-dataviewer></mentoring-dataviewer>
-</vertical>