megrok.layout 1.3

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:

>>> from megrok.layout import Layout
>>> from zope.interface import Interface
>>> import grokcore.component as grok

>>> 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((TestRequest(), Interface), 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.Context):
...    description = u'Looks like a bull'

>>> class Mammoth(grok.Context):
...    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.content()
u'Looks like an elephant'
>>> page()
u'a simple layout'

As we can see, the page is 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, by using our page with the help of the ‘content’ method:

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

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

Forms & Errorpages

Baseclasses for Form views (Form, AddForm, EditForm and DisplayForm) and Error views (NotFoundPage, ExceptionPage, UnauthorizedPage) are available which are all aware of Layout components like Page is.

Changelog