Forms

Flask-Velox comes with SQLAlchemy form integration to hopefully make those Create / Update tasks as simple as possible.

Note

The following packages must be installed:

• Flask-SQLAlchemy
• Flask-WTF

Create View

The CreateModelView allows you to render a form and on successful validation of the form creates a new object and saves to the database. You will ofcourse need to make the form yourself, you could use WTForms-Alchemy to automate this for you, example below:

This view is almost identical to the Form View we have seen before except that the view mixis in the ability to create an object populated with data from the form and save that object. You can see how the success callback function works here:

• flask_velox.mixins.sqla.forms.BaseCreateUpdateMixin.success_callback()

from flask.ext.wtf import Form
from flask.ext.velox.views.sqla import forms
from wtforms import TextField
from yourapp import db

class MyModel(db.Model):
    field1 = db.Column(db.String(20))
    field2 = db.Column(db.String(128))

class MyForm(Form):
    field1 = TextField()
    field2 = TextField()

class MyCreateView(forms.CreateModelView):
    model = MyModel
    session = db.session
    form = MyForm
    template = 'create.html'

You will ofcourse need a template for rendering the form, see an Example Template in the Form View guide.

As with the Form View you can override the success callback function, redirect url etc.

Update View

The Update View follows the same principle as the Create View except that the form is instantiated with an existing object which you can see documented here:

• flask_velox.mixins.sqla.forms.UpdateModelFormMixin.instantiate_form()

class MyUpdateView(forms.UpdateModelView):
    model = MyModel
    session = db.session
    form = MyForm
    template = 'update.html'

Multi Form Update View

There can sometimes be the requirement for multiple forms to update a single object which offer different functionality, an example situation is updating a user object where a password change form needs to be seperate from the general user attributes form. This view allows us to do this.

Again it follows the same principles as the Create View and Update View.

See also

• Multi Form View

from flask.ext.velox.views.sqla import forms
from yourapp import db
from yourapp.forms import UserPasswordForm, UserUpdateForm
from yourapp.models import User

class MyMultiFormView(forms.UpdateModelMultiFormView):
    model = User
    session = db.sesion
    forms = [
        ('Change Password', UserPasswordForm)
        ('Update User', UserUpdateForm)
    ]
    template = 'mutli.html'

You can see an example template here.