grokcore.layout 1.5

A layout component package for zope3 and Grok.

The grokcore.layout package provides a simple way to write view components which can be included into a defined layout. It turns around two main components : the Page and the Layout.

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 grokcore.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 grokcore.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 grokcore.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 (FormPage, AddFormPage, EditFormPage and DisplayFormPage) and Error views (NotFoundPage, ExceptionPage, UnauthorizedPage) are available which are all aware of Layout components like Page is.

Changelog

1.5 (2012-05-02)

• Move the layout-aware form components to the grok package where the dependency with grokcore.formib can be mixed in.

• Add a directive layout to select a different type of layout. A layout type is defined on a Layout component with the help of the grokcore.component.provides directive. It defaults to ILayout for compatibility.

• Change how the static resources are associated to a Layout, using the new name __static_name__ set by the template grokker.

1.4 (2011-07-13)

• Rename megrok.layout to grokcore.layout. application_url and flash utilities have been removed, *Form components have been renamed to *FormPage.

• Added ExceptionPage, NotFoundPage and UnauthorizedPage layout-aware components.

• Fixed default template for grokcore.layout.Form component.

1.3 (2011-01-12)

• Compatibility with grokcore.view 2.3.

1.2.0 (2010-12-16)

• Update to use the new TemplateGrokker from grokcore.view.

1.1.0 (2010-03-03)

• z3c.flashmessage has been dropped in favor of grokcore.message. This new package takes in charge the registration of the utilities and retains the existing API. The back-compatibility is assured.

1.0.2 (2010-02-26)

• The existence test for the application_url site-lookup was wrongly using a “if not” statement. In a case of a container, the object is evaluated to False if it’s empty. We now use a proper “if .. is None”. [trollfot]

1.0.1 (2010-02-25)

• Forms now inherit from UtilityView and therefore get the application_url and flash methods. Tests have been added to garanty the behavior. [trollfot]

1.0 (2010-02-25)

• The dependencies have been heavily cleaned up. All zope.app packages have been removed. We are now running with minimal dependencies and using the latest ZTK. This release will probably not run on Grok 1.0. You will need Grok 1.1rc1 to be able to use it. [trollfot]

• Added a component called UtilityView that provides two useful methods : application_url, flash. These methods are almost a copy of what can be found in the Grok package. The application_url is using a simple getSite hook to get the root of the application. This might be irrelevant for some applications and can be overriden. [trollfot]

• Added a module called ‘messages’ that contains the flash messages utilities. This module is NOT grokked and must be grokked manually. This prevents conflicts with grokui.admin’s own definitions of the very same components. It also allows you to override the flash method to use something else than z3c.flashmessage and then not be bothered by useless utilities. The flash messages utilities can be registered by including the messages.zcml file in your own project or package ZCML file. [trollfot]

0.9 (2009-09-26)

• Add default templates to form which doesn’t contain an html and body tag. [sylvain]

• Add an AddForm, EditForm and DisplayForm, all aware of the layout component. [sylvain]

0.8 (2009-09-17)

• Remove the CodePage, since CodeView have been removed from grokcore.view. [sylvain]

0.7 (2009-09-15)

• Add a CodePage to be compatible with the last version of grokcore.view (higher than 1.9). This breaks compatibility with previous release. You need to change any Page using a render method to a CodePage. [sylvain]

• The content property on a Page is no longer a property, but a method as it’s hidding exceptions. You might need to update your code to reflect that change as well. [sylvain]

• Fix MANIFEST.in. [sylvain]

0.6 (2009-09-14)

• switch the arguments order in calling the layout [cklinger, sylvain]

• add the CHANGES.txt [cklinger]

0.5 (2009-07-24)

• remove the grok dependency [cklinger trollfot]