megrok.layout 0.3

Getting started

First we grok this package’s grokkers:

>>> import grok.testing
>>> from grok.testing import grok_component
>>> grok.testing.grok('megrok.layout.meta')

Layout

The layout is a component allowing you to design your site. Often, it’s the common structure shared between all the pages. Technically, it is a class based on the view components interface, providing a ‘render’ and ‘update’ method.

Let’s implement a simple Layout:

>>> import grok
>>> from megrok.layout import Layout
>>> from zope.interface import Interface

>>> class MyLayout(Layout):
...     grok.name('mylayout')
...     grok.context(Interface)
...
...     def render(self):
...         return u"a simple layout"

We grok our component:

>>> grok_component('MyLayout', MyLayout)
True

We check it has been correctly registered:

>>> from megrok.layout import ILayout
>>> from zope.component import getMultiAdapter
>>> from zope.publisher.browser import TestRequest

>>> layout = getMultiAdapter((Interface, TestRequest()), ILayout)
>>> isinstance(layout, MyLayout)
True
>>> layout.render()
u'a simple layout'

Now let’s see how to use this Layout in a specific context using a Page.

Page

The page is the specific code that you want to control. It is based on the grokcore.View browser page implementation and therefore provides a ‘render’ and ‘update’ method. The ‘render’ method will simply return the specific HTML code generated by the template or the ‘render’ method code while ‘__call__’ will lookup for a Layout component and renders itself inside it.

First, we’ll create 2 models that will serve as exemples.

>>> class Aurochs(grok.Model):
...    description = u'Looks like a bull'

>>> class Mammoth(grok.Model):
...    description = u'Looks like an elephant'

Let’s create now a page that will display their description.

>>> from megrok.layout import Page
>>> class AnimalDisplay(Page):
...    grok.name('display')
...    grok.context(Interface)
...
...    def render(self):
...        return self.context.description

Grokking our Page will let us use it.

>>> grok_component('AnimalDisplay', AnimalDisplay)
True
>>> wooly = Mammoth()
>>> page = getMultiAdapter((wooly, TestRequest()), name='display')
>>> page.render()
u'Looks like an elephant'
>>> page()
u'a simple layout'

As we can see, the page us using the layout, on the __call__ to render. Of course, this example Layout doesn’t provide any interesting feature. Let’s create something more interesting.

>>> class MammothLayout(Layout):
...     grok.context(Mammoth)
...
...     def render(self):
...         return u'Header. Page: %s. Footer' % self.view.render()

>>> grok_component('MammothLayout', MammothLayout)
True
>>> page()
u'Header. Page: Looks like an elephant. Footer'