Add 'Image Upload' Feature

Each user can upload image to the system. The images from different users where be separated.

app.py

@@ -1,6 +1,13 @@
+import os
+import datetime
+import hashlib
 from flask import Flask, session, url_for, redirect, render_template, request, abort, flash
 from database import list_users, verify, delete_user_from_db, add_user
 from database import read_note_from_db, write_note_into_db, delete_note_from_db, match_user_id_with_note_id
+from database import image_upload_record, list_images_for_user
+from werkzeug.utils import secure_filename
+
+
 
 app = Flask(__name__)
 app.config.from_object('config')
@@ -23,6 +30,10 @@ def FUN_404(error):
 def FUN_405(error):
     return render_template("page_405.html"), 405
 
+@app.errorhandler(413)
+def FUN_413(error):
+    return render_template("page_413.html"), 413
+
 
 
 
@@ -43,7 +54,13 @@ def FUN_private():
                           [x[1] for x in notes_list],\
                           [x[2] for x in notes_list],\
                           ["/delete_note/" + x[0] for x in notes_list])
-        return render_template("private_page.html", notes = notes_table)
+
+        images_list = list_images_for_user(session['current_user'])
+        images_table = zip([x[0] for x in images_list],\
+                          [x[1] for x in images_list],\
+                          [x[2] for x in images_list])
+
+        return render_template("private_page.html", notes = notes_table, images = images_table)
     else:
         return abort(401)
 
@@ -76,6 +93,36 @@ def FUN_delete_note(note_id):
         delete_note_from_db(note_id)
     else:
         return abort(401)
+    return(redirect(url_for("FUN_private")))
+
+
+# Reference: http://flask.pocoo.org/docs/0.12/patterns/fileuploads/
+ALLOWED_EXTENSIONS = set(['png', 'jpg', 'jpeg', 'gif'])
+def allowed_file(filename):
+    return '.' in filename and \
+           filename.rsplit('.', 1)[1].lower() in ALLOWED_EXTENSIONS
+
+@app.route("/upload_image", methods = ['POST'])
+def FUN_upload_image():
+    if request.method == 'POST':
+        # check if the post request has the file part
+        if 'file' not in request.files:
+            flash('No file part')
+            return(redirect(url_for("FUN_private")))
+        file = request.files['file']
+        # if user does not select file, browser also submit a empty part without filename
+        if file.filename == '':
+            flash('No selected file')
+            return(redirect(url_for("FUN_private")))
+        if file and allowed_file(file.filename):
+            filename = secure_filename(file.filename)
+            upload_time = str(datetime.datetime.now())
+            image_uid = hashlib.sha1(upload_time + filename).hexdigest()
+            # Save the image into UPLOAD_FOLDER
+            file.save(os.path.join(app.config['UPLOAD_FOLDER'], image_uid + "-" + filename))
+            # Record this uploading in database
+            image_upload_record(image_uid, session['current_user'], filename, upload_time)
+            return(redirect(url_for("FUN_private")))
 
     return(redirect(url_for("FUN_private")))
 
@@ -83,6 +130,7 @@ def FUN_delete_note(note_id):
 
 
 
+
 @app.route("/login", methods = ["POST"])
 def FUN_login():
     id_submitted = request.form.get("id").upper()

config.py

@@ -1 +1,3 @@
 SECRET_KEY = "fdsafasd"
+UPLOAD_FOLDER = "image_pool"
+MAX_CONTENT_LENGTH = 16 * 1024 * 1024

database.py

@@ -4,6 +4,7 @@ import datetime
 
 user_db_file_location = "database_file/users.db"
 note_db_file_location = "database_file/notes.db"
+image_db_file_location = "database_file/images.db"
 
 def list_users():
     _conn = sqlite3.connect(user_db_file_location)
@@ -41,6 +42,13 @@ def delete_user_from_db(id):
     _conn.commit()
     _conn.close()
 
+    # when we delete a user from database USERS, we also need to delete all his or her images data from database IMAGES
+    _conn = sqlite3.connect(image_db_file_location)
+    _c = _conn.cursor()
+    _c.execute("delete from images where owner = '" + id + "';")
+    _conn.commit()
+    _conn.close()
+
 def add_user(id, pw):
     _conn = sqlite3.connect(user_db_file_location)
     _c = _conn.cursor()
@@ -101,6 +109,30 @@ def delete_note_from_db(note_id):
     _conn.commit()
     _conn.close()
 
+def image_upload_record(uid, owner, image_name, timestamp):
+    _conn = sqlite3.connect(image_db_file_location)
+    _c = _conn.cursor()
+
+    command = "insert into images values ('{0}', '{1}', '{2}', '{3}');".format(uid, owner, image_name, timestamp)
+    _c.execute(command)
+
+    _conn.commit()
+    _conn.close()
+
+def list_images_for_user(owner):
+    _conn = sqlite3.connect(image_db_file_location)
+    _c = _conn.cursor()
+
+    command = "select uid, timestamp, name from images where owner = '{0}'".format(owner)
+    _c.execute(command)
+    result = _c.fetchall()
+
+    _conn.commit()
+    _conn.close()
+
+    return result
+
+
 
 
 

templates/index.html

@@ -13,6 +13,7 @@
         <li>Integrating with Bootstrap</li>
         <li>Interaction with Database (SQLite)</li>
         <li>Invoking static resources</li>
+        <li>Upload files</li>
     </ul>
 
     <p>For more basic knowledge of Flask, you can refer to <a href="https://www.tutorialspoint.com/flask/">a tutorial on Tutorialspoint</a>.</p>

templates/page_413.html

@@ -0,0 +1,6 @@
+{% extends "layout.html" %}
+{% block page_title %}Request if too big(413){% endblock %}
+{% block body %}
+    {{ super() }}
+    Please check the file size you're uploading.
+{% endblock %}

templates/private_page.html

@@ -43,4 +43,32 @@
         </table>
     {% endif %}
 
+    <hr>
+    <h3>Upload Image</h3>
+    <form method='post' action='/upload_image' enctype=multipart/form-data>
+      <p><input type=file name=file>
+         <input type=submit value=Upload>
+    </form>
+
+    {% if images %}
+        <h3>Your Images</h3>
+        <table class="table small">
+            <thead>
+                <tr>
+                  <th>Image ID</th>
+                  <th>Timestamp</th>
+                  <th>Image Name</th>
+                </tr>
+            </thead>
+            {% for image_id, timestamp, image_name in images %}
+                    <tr>
+                       <td> {{ image_id }} </td>
+                       <td> {{ timestamp }} </td>
+                       <td> {{ image_name }} </td>
+                    </tr>
+                    
+            {% endfor %}
+        </table>
+    {% endif %}
+
 {% endblock %}