## Modals for Flask
Use forms in Bootstrap modals with Flask.
### Description
Plain forms can be boring. Using them in modals is possible, but requires
JavaScript. Normal form submission in modals is problematic.
This Flask extension eases the process of using forms in Bootstrap modals.
Bootstrap versions 4 and 5 are supported. No JavaScript coding is required on
your part. You can code in pure Python - flashing messages and rendering
templates.
### Installation
```Shell
pip install Flask-Modals
```
### Setup
1. Import the `Modal` class and instantiate it in your `app.py` file.
```Python
from flask_modals import Modal
app = Flask(__name__)
modal = Modal(app)
```
You will also need a secret key in the app config (not shown).
<br>
2. Alternatively if you are using the application factory pattern:
```Python
from flask_modals import Modal
modal = Modal()
def create_app():
app = Flask(__name__)
modal.init_app(app)
```
<br>
3. Include the following in the head tag of your base template.
```html
{{ modals() }}
```
<br>
4. Include the following in the modal body.
```html
<div class="modal-body">
{{ modal_messages() }}
<form method="post">
...
```
### Basic usage
You only need to import the function `render_template_modal` in your `routes.py`
file. Use it instead of `render_template` in the route handler for the page with
the modal form. It takes an extra argument - `modal` (the modal `id` with a default
of `modal-form`).
<br>
The extension works by submitting the modal form twice - first via
ajax and then, if all validations pass, normally. When submiited via ajax, it
passes a field '_ajax' with the form, which can be used as shown below.
Example route handler:
```Python
from flask_modals import render_template_modal
@app.route('/', methods=['GET', 'POST'])
def index():
ajax = '_ajax' in request.form # Add this line
form = LoginForm()
if form.validate_on_submit():
if form.username.data != 'test' or form.password.data != 'pass':
flash('Invalid username or password', 'danger')
return redirect(url_for('index'))
if ajax: # Add these
return '' # two lines
login_user(user, remember=form.remember_me.data)
flash('You have logged in!', 'success')
return redirect(url_for('home'))
# Add this line
return render_template_modal('index.html', form=form)
```
### Other usage
If you want to render a template and not redirect:
```Python
@app.route('/', methods=['GET', 'POST'])
def index():
ajax = '_ajax' in request.form
form = LoginForm()
if form.validate_on_submit():
if form.username.data != 'test' or form.password.data != 'pass':
flash('Invalid username or password', 'danger')
return render_template_modal('index.html', form=form)
if ajax:
return ''
login_user(user, remember=form.remember_me.data)
flash('You have logged in!', 'success')
return render_template_modal('index.html', form=form)
return render_template_modal('index.html', form=form)
```
If the above looks verbose, you can use the `response` decorator and
return a context dictionary, like so:
```Python
from flask_modals import response
@app.route('/', methods=['GET', 'POST'])
@response('index.html')
def index():
...
...
return {'form': form}
```
<br>
### Note
1. See the examples folder in the repo for more details.
2. The extension loads the NProgress js library to display a progress bar during
form submission.
