sample single file templateless flask application that demonstrates flask_bootstrap, flask_wtform, flask_nav, flask_login, and dominate

sample_dominate.py

'''
 sample single file templateless flask application that demonstrates flask_bootstrap, flask_wtform, flask_nav, flask_login
 uses dominate instead of templates
 to use: (in virtual env)
pip install dominate Flask Flask-Bootstrap Flask-WTF flask-nav Flask-Login
python sample_dominate.py

'''

from flask import Flask, session, request, redirect, render_template_string, flash
from flask.sessions import SecureCookieSessionInterface

from flask_bootstrap import Bootstrap,bootstrap_find_resource, render_form

from flask_login import LoginManager, UserMixin, login_required, login_user, logout_user , current_user


from flask_wtf import FlaskForm
from wtforms import StringField,PasswordField,SubmitField
from wtforms.validators import DataRequired

import dominate as dom
import dominate.tags as t
from dominate.util import raw

from flask_nav import Nav
from flask_nav.elements import Navbar, View, Subgroup, Link, Text, Separator

from functools import wraps

app = Flask(__name__)
Bootstrap(app)

app.secret_key = "rAxIqk4mMZkc6VYWwndDDCNg5D6q0AUDs11pGENoNoeo3V1SWVebuOO5XizEevDxl3wVQHRDnp7skeoU"
app.session_interface = SecureCookieSessionInterface();

# login form
class LoginForm(FlaskForm):
    login = StringField('Login', validators=[DataRequired()])
    passwd = PasswordField('Passwd', validators=[DataRequired()])
    submit_button = SubmitField('Login')

# dominate tag which has no tag. useful for example to add js script at end of body
class noTag(t.html_tag):
    def _render(self, sb, indent_level=1, indent_str='  ', pretty=True, xhtml=False):
        pretty = self._render_children(sb, indent_level , indent_str, pretty, xhtml)


## flask form template rendering (render_form is unfortunately not finished)
formTemplate='''
{%% import "bootstrap/wtf.html" as wtf %%}
{{ wtf.quick_form(form, form_type='%s'%s) }}
'''
def renderForm(form, formType='basic', extraArg='') :
    return raw(render_template_string(formTemplate%(formType,extraArg),form=form))


### nav
nav=Nav()
nav.init_app(app)

barGroup = Subgroup( # static subgroup
        'Docs',
        Link('Flask-Bootstrap', 'http://pythonhosted.org/Flask-Bootstrap'),
        Link('Flask-AppConfig', 'https://github.com/mbr/flask-appconfig'),
        Link('Flask-Debug', 'https://github.com/mbr/flask-debug'),
        Separator(),
        Text('Bootstrap'),
        Link('Getting started', 'https://v4-alpha.getbootstrap.com/getting-started/introduction/'),
        Link('Layout', 'https://v4-alpha.getbootstrap.com/layout/overview/'),
        Link('Content', 'https://v4-alpha.getbootstrap.com/content/reboot/'),
        Link('Components', 'https://v4-alpha.getbootstrap.com/components/alerts/'),
        Link('Utilities', 'https://v4-alpha.getbootstrap.com/utilities/borders/'),
        Link('About', 'https://v4-alpha.getbootstrap.com/about/history/'),
)

def topBar():
    # dynamic nav bar
    return Navbar(*(
        [   View('Flask-Bootstrap', '.hello')
        ,   View('Dashboard', '.dash')
        ]
    +   [   View('Logout', '.logout')] * current_user.is_authenticated
    +   [   Text('Welcome %s'%('guest' if not current_user.is_authenticated else current_user.id))
        ,   barGroup  
        ]
    ))

## flask_login minimal user class
class User(UserMixin):
    def __init__(self,id):
        self.id = id

login_manager = LoginManager()
login_manager.init_app(app)
login_manager.login_view = "login"

@login_manager.user_loader
def load_user(userid):
    return User(userid)

# this is our bootstrap document template
def getDoc() :
    doc = dom.document(title="mypage")

    with doc.head:
        t.meta(name="viewport",content="width=device-width, initial-scale=1.0")
        t.link(href=bootstrap_find_resource('css/bootstrap.css', cdn='bootstrap'),rel="stylesheet")

    doc.body, doc.bodyEnd = doc.body.add(t.div(_class="container"), noTag(t.comment("bodyEnd")))
    with doc.body:
        topBar().render()
        # TBD: display flash messages

    with doc.bodyEnd:
        t.script(src=bootstrap_find_resource('jquery.js', cdn='jquery'))
        t.script(src=bootstrap_find_resource('js/bootstrap.js', cdn='bootstrap'))
    return doc

#decorator that calls our template
def stdDoc(func):
    @wraps(func)
    def wrap():
        doc=getDoc()
        with doc.body:
            r=func()
            if r is not None:
                return r
        return doc.render()
    return wrap
    

@app.route('/login',methods=['GET','POST'])
@stdDoc
def login():
    form = LoginForm(request.form)
    if request.method=='POST' and form.validate_on_submit():  # to get error messages to the browser
        if form.login.data == form.passwd.data:
            user=User(form.login.data)
            login_user(user)
            flash("Login Ok!")
            return redirect(request.args.get("next"))
        else:
            form.passwd.errors=["wrong password"]

    with t.div(_class="jumbotron"):
        t.h1("Please login")
        t.p("Password must equal to login in this example")
        renderForm(form, formType='horizontal')

@app.route("/logout")
def logout():
    logout_user() # call logout_user before getDoc to update the navbar
    doc=getDoc()
    with doc.body:
        t.h1("Logout done")
    return doc.render()
    
    
@app.route("/dash")
@login_required
@stdDoc
def dash():
    t.h1("Welcome %s"%current_user.id)


@app.route('/')
@stdDoc
def hello():
    t.h1("Welcome!")
    
if __name__ == '__main__':
    app.run(debug=True, host="0.0.0.0")