edit the form is not working - flask

Question

Merry Christmas!!!!I work with flask sqlalchemy and wtf. I could create new and would display in info.html But when I try to edit the form there is no changes in database So it is not working. So I wonder where is issues?
app.py
#With this route I can add new form in database
#app.route('/contact', methods=['GET', 'POST'])
def contact():
form = LoginForm(request.form)
if request.method == 'POST':
if form.validate()== True:
contact = Contacts()
# populate the model
form.populate_obj(contact)
db.session.add(contact)
db.session.commit()
# Contact commited to database
# RETURN TO INFO.HTML
return redirect(url_for('info'))
else:
#If the form does not have all fields that are required
return render_template('contact.html', form=form)
# This is the part for edit which is not working
# so I query and populate it but no change none in
# database none in info.html
#app.route('/edit/<int:id>', methods=['POST'])
def edit(id=None):
user = Contacts.query.get_or_404(id)
form = LoginForm(request.form,obj=user)
# check the validate and then populate the obj
if form.validate_on_submit()== True:
#populate it
form.populate_obj(user)
db.session.commit()
return redirect(url_for('info'))
else:
#If the form does not have all fields that are required
return render_template('edit.html', id=id )
#app.route('/edit/<int:id>', methods=['GET'])
def profile(id=None):
user = Contacts.query.get_or_404(id)
form = LoginForm(request.form, obj=user)
return render_template('edit.html',form=form, id =id)
# this route to html that should show all info
#app.route('/info', methods=['GET', 'POST'])
def info():
#query all
info = Contacts.query.all()
return render_template('info.html', contact=info)
model.py
# model with table name Contacts
class Contacts(db.Model):
__tablename__ = "Contacts"
id = db.Column(db.Integer, primary_key = True)
name = db.Column(db.String(50))
email = db.Column(db.String(50))
age = db.Column(db.Integer)
form.py
# this is the form wtf
Class LoginForm(Form):
name = StringField("Name", [validators.Required("Please enter your name.")])
email = StringField("Email", [validators.Required("Please enter your email address."), validators.Email("Please enter valid email address.")])
age = IntegerField("age", [validators.Required("Please enter your age.")])
submit = SubmitField("Submit")
info.html
# it should display all updated form But it wont??
{% extends "layout.html" %}
{% block content %}
<h2>show the info</h2>
{% for contact in contact %} # Maybe this is also Problem?
<strong>name:</strong> {{ contact.name}} <br>
<strong>email:</strong> {{ contact.email }} <br>
<strong>age:</strong> {{ contact.age}} <br>
<br>
{% endfor %}
{% endblock %}

Answer 1

You don't have to readd a Object, when you get it per query. The Queryobject is bound to the session. So you only need to commit the changes and not to add them again.
so this should be the corrected code snippet
user = Contacts.query.get_or_404(id)
form = LoginForm(request.form,obj=user)
# check the validate and then populate the obj
if form.validate()== True:
# populate it
form.populate_obj(user)
db.session.commit()

Answer 2

I tried your code on my machine. With little modification in code I was able to update database.
Please find updated chunk below:
#app.route('/edit/<int:id>', methods=['POST'])
def submit(id=None):
user = Contacts.query.get_or_404(id)
form = LoginForm(request.form,obj=user)
#return render_template('edit.html', form=form, id=1 )
if form.validate() == True:
form.populate_obj(user)
db.session.commit()
return redirect(url_for('info'))
else:
return redirect(url_for(edit, id=id))
#app.route('/edit/<int:id>', methods=['GET'])
def edit(id=None):
user = Contacts.query.get_or_404(id)
form = LoginForm(request.form,obj=user)
return render_template('edit.html', form=form, id=id )

Answer 3

I know this is an older question, but I'm referencing from Why doesn't my WTForms-JSON form update correctly?.
Essentially, you need to initialize the Form first then check to see if it was submitted or not:
form = FormBuilder()
if not form.is_submitted():
form = FormBuilder.populate_obj(obj)
else:
form = FormBuilder() # will populate from submitted data
if form.validate_on_submit():
It helped me when having the same issues.