BUG allow user to download a submission (#397)

Author: glemaitre

doc/whats_new/v0.5.rst

@@ -15,9 +15,13 @@ Changelog
 `ramp-frontend`
 ...............
 
+- Bug: fix a bug for which it was impossible to download a submission
+  via the frontend.
+  :pr:`397` by :user:`Guillaume Lemaitre <glemaitre>`.
+
 `ramp-utils`
 ............
 
 - Enhancement: add :func:`ramp_utils.datasets.fetch_from_osf` allowing to fetch
   a file from OSF.
-  By :pr:`396` by :user:`Guillaume Lemaitre <glemaitre>`.
+  :pr:`396` by :user:`Guillaume Lemaitre <glemaitre>`.

ramp-frontend/ramp_frontend/tests/test_ramp.py

@@ -803,3 +803,26 @@ def test_toggle_competition(client_session):
         assert b"Pull out this submission from the competition" in rv.data
         session.commit()
         assert submission.is_in_competition
+
+
+def test_download_submission(client_session):
+    client, session = client_session
+
+    # unknown submission
+    with login_scope(client, 'test_user', 'test') as client:
+        rv = client.get("download/xxxxx")
+        assert rv.status_code == 302
+        assert rv.location == 'http://localhost/problems'
+        with client.session_transaction() as cs:
+            flash_message = dict(cs['_flashes'])
+        assert "Missing submission" in flash_message['message']
+
+    submission = (session.query(Submission)
+                         .filter_by(name="starting_kit_test",
+                                    event_team_id=1)
+                         .first())
+
+    with login_scope(client, 'test_user', 'test') as client:
+        rv = client.get(f"download/{submission.hash_}")
+        assert rv.status_code == 200
+        assert rv.data

ramp-frontend/ramp_frontend/views/ramp.py

@@ -1,9 +1,12 @@
 import datetime
 import difflib
 import logging
+import io
 import os
 import shutil
 import tempfile
+import time
+import zipfile
 
 from bokeh.embed import components
 
@@ -15,6 +18,7 @@
 from flask import render_template
 from flask import request
 from flask import send_from_directory
+from flask import send_file
 
 from wtforms import StringField
 from wtforms.widgets import TextArea
@@ -992,3 +996,42 @@ def toggle_competition(submission_hash):
     return redirect(
         '/{}/{}'.format(submission_hash, submission.files[0].f_name)
     )
+
+
+@mod.route("/download/<submission_hash>")
+@flask_login.login_required
+def download_submission(submission_hash):
+    """Download a submission from the server.
+
+    Parameters
+    ----------
+    submission_hash : str
+        The submission hash of the current submission.
+    """
+    submission = (Submission.query.filter_by(hash_=submission_hash)
+                                  .one_or_none())
+    if submission is None:
+        error_str = 'Missing submission: {}'.format(submission_hash)
+        return redirect_to_user(error_str)
+
+    access_code = is_accessible_code(
+        db.session, submission.event_team.event.name,
+        flask_login.current_user.name, submission.id
+    )
+    if not access_code:
+        error_str = 'Unauthorized access: {}'.format(submission_hash)
+        return redirect_to_user(error_str)
+
+    file_in_memory = io.BytesIO()
+    with zipfile.ZipFile(file_in_memory, 'w') as zf:
+        for ff in submission.files:
+            data = zipfile.ZipInfo(ff.f_name)
+            data.date_time = time.localtime(time.time())[:6]
+            data.compress_type = zipfile.ZIP_DEFLATED
+            zf.writestr(data, ff.get_code())
+    file_in_memory.seek(0)
+    return send_file(
+        file_in_memory,
+        attachment_filename=f"submission_{submission.id}.zip",
+        as_attachment=True,
+    )