added upload new version of file into edit form

app/forms.py

@@ -25,6 +25,7 @@ class EditForm(FlaskForm):
     author = FieldList(FormField(AuthorForm, default=lambda: Author()), min_entries=1)
     category = StringField('category', validators=[InputRequired()])
     year_published = StringField('year published', [validators.Length(max=4)],default=None)
+    file = FileField()
 
 class ChatForm(FlaskForm):
     message = StringField('message', validators=[InputRequired()])

app/templates/edit_book_detail.html

@@ -7,7 +7,7 @@
 
 
 
-  <form method="POST" action="{{ url_for('edit_book_by_id', id=book.id )}}">
+  <form method="POST" action="{{ url_for('edit_book_by_id', id=book.id )}}" enctype=multipart/form-data>
     {{ form.csrf_token }}
 
     <div class="form-group"><h1 class="header">{{ form.title.label }} {{ form.title(size=20, class="form-control") }}</h1></div>
@@ -32,10 +32,19 @@
         </table>
     </div><br>
     <div class="form-group">
-    {{ form.category.label }} {{ form.category(size=20, class="form-control") }}
+    {{ form.category.label }} {{ form.category(size=20, 
+    class="form-control") }}
   </div><br>
   <div class="form-group">
   {{ form.year_published.label }} {{ form.year_published(size=4, class="form-control") }}
+</div>
+<div class="form-group">
+  Current file: {{ book.file }}
+</div>
+<div class="form-group">
+
+  Upload new file: {{form.file}} 
+
 </div>
     <br>
     <button type="submit" class="btn btn-primary">Update</button>

app/views.py

@@ -134,16 +134,13 @@ def edit_book_by_id(id):
 
     if request.method == 'POST':
         if user_form.validate_on_submit():
-            # check if the post request has the file part
-            title = user_form.title.data # You could also have used request.form['name']
-            input_authors = user_form.author.data # You could also have used request.form['email']
+            # on submit, check fields
+            title = user_form.title.data
+            input_authors = user_form.author.data 
             category = user_form.category.data
             year_published = user_form.year_published.data
             if year_published=="":
                 year_published = None
-            # save user to database
-            #book = Book(title, author, filename, cover, file_extension)
-
             book = Book.query.filter_by(id=id).first()
             book.title = title
             book.category = category
@@ -159,6 +156,26 @@ def edit_book_by_id(id):
                         a = Author(author_name=author_name)
                         db.session.add(a)
                     book.authors.append(a)
+
+            # editing / uploading new file
+            if user_form.file.data:
+                file = request.files['file']
+                if file.filename == '':
+                    flash('No selected file')
+                    return redirect(request.url)
+                if file and allowed_file(file.filename):
+                    filename = secure_filename(file.filename)
+                    allbooks = db.session.query(Book).all()
+                    id = book.id
+                    new_filename = str(id) +"_"+ filename
+                    fullpath = os.path.join(app.config['UPLOAD_FOLDER'], new_filename)
+                    name, file_extension = os.path.splitext(new_filename)
+                    file.save(fullpath)
+                    book.cover = get_cover(fullpath, name)
+                    book.file = new_filename
+                else:
+                    flash('allowed file formats: %s' % ALLOWED_EXTENSIONS)
+
             db.session.commit()
             flash("%s updated" % (title))
             return redirect(url_for('show_book_by_id', id=id))