This is incomplete documentation in progress

Getting Started: A basic page

Currently the nevow.rend module contains the Page class which should be subclassed to create new pages. A page is the added as a child of the root page, or it's instantiation can be defined in a childFactory or child_ special method. rend.Page contains the context which is slowly being removed and will soon be replaced by page.Page which should be easily adaptable.

We will construct a page that returns "Hello world!", and propose some structural alternatives.

from nevow import rend, loaders, tags

class APage(rend.Page):
    docFactory = loaders.stan(tags.html[
        tags.head[
            tags.title["Hello World Example"]
        ],
        tags.body[
            tags.div(id="hello", _class="helloicator")["Hello World!"]
        ]
    ])

This page uses Stan to construct an object-like representation which is flattened into XHTML.

Rendering can also dispatch methods inside the page class known as render specials.

from nevow import rend, loaders, tags

class APage(rend.Page):
    docFactory = loaders.stan(tags.html[
        tags.head[
            tags.title["Hello World Example"]
        ],
        tags.body[
            tags.div(render=tags.directive('hi'))
        ]
    ])

    def render_hi(self, ctx, data):
        return ctx.tag[ tags.div(id="hello", _class="helloicator")["Hello World"]]

Putting it together

To put it together as a deployable application all we really need is an application servlet.

A compact example of a boiler plate Nevow application could look like this

# Page modules
from nevow import rend, loaders, tags

# Deployment modules
from nevow import appserver
from twisted.application import service, internet

class APage(rend.Page):
    addSlash = True

    docFactory = loaders.stan(tags.html[
        tags.head[
            tags.title["Hello World Example"]
        ],
        tags.body[
            tags.div(render=tags.directive('hi'))
        ]
    ])

    def render_hi(self, ctx, data):
        return ctx.tag[ tags.div(id="hello", _class="helloicator")["Hello World"]]


siteRoot = APage() # Set our page as the site root
site = appserver.NevowSite(siteRoot)

demo = internet.TCPServer(8080, site)

application = service.Application('demo')
demo.setServiceParent(application)

It's common to encapsulate the specific service in a deployment function as follows

# Page modules
from nevow import rend, loaders, tags

# Deployment modules
from nevow import appserver
from twisted.application import service, internet

class APage(rend.Page):
    addSlash = True

    docFactory = loaders.stan(tags.html[
        tags.head[
            tags.title["Hello World Example"]
        ],
        tags.body[
            tags.div(render=tags.directive('hi'))
        ]
    ])

    def render_hi(self, ctx, data):
        return ctx.tag[ tags.div(id="hello", _class="helloicator")["Hello World"]]

def deployApp():
    siteRoot = APage() # Set our page as the site root
    site = appserver.NevowSite(siteRoot)
    return site

demo = internet.TCPServer(8080, deployApp())

application = service.Application('demo')
demo.setServiceParent(application)

The server can be started by issuing the command twistd -ny simple.py

Note: It is possible to attach multiple sites and protocol servers to a single service parent.