Helper views and tools¶
This document explains how to access view and context utilities in Plone.
IPortalState and IContextState¶
IContextState view-like interfaces
to access miscellaneous information useful for the rendering of the current page.
The views are cached properly, they should access the information effectively.
IPortalStateis mapped as the
IContextStateis mapped as the
IToolsis mapped as the
To see what’s available through the interface, read the documentation in the plone.app.layout.globals.interfaces module.
Example showing how to get the portal root URL:
from zope.component import getMultiAdapter ... class MyView(BrowserView): ... def __call__(self): # aq_inner is needed in some cases like in the portlet renderers # where the context itself is a portlet renderer and it's not on the # acquisition chain leading to the portal root. # If you are unsure what this means always use context.aq_inner context = self.context.aq_inner portal_state = getMultiAdapter((context, self.request), name=u'plone_portal_state') self.some_url = portal_state.portal_url() + "/my_foo_bar"
Example showing how to get the current language:
from zope.component import getMultiAdapter ... portal_state = getMultiAdapter((self.context, self.request), name=u'plone_portal_state') current_language = portal_state.language()
Example showing how to expose
portal_state helper to a template:
<browser:page for="*" name="test" permission="zope2.Public" class=".views.MyView" allowed_attributes="portal_state" />
A Python class exposes the variable:
from Acquisition import aq_inner from zope.component import getMultiAdapter class MyView(BrowserView): def portal_state(self): context = aq_inner(self.context) portal_state = getMultiAdapter((context, self.request), name=u'plone_portal_state') return portal_state
Templates can use it as follows:
<div> The language is <span tal:content="view/portal_state/language" /> </div>
You can directly look up
portal_state in templates using acquisition
and view traversal, without need of ZCML code
or Python view code changes. This is useful e.g. in overridden
<!-- During traversal, ``@@`` signals that the traversing machinery should look up a view by that name. First we look up the view and then use it to access the variables defined in ``IPortalState`` interface. --> <div tal:define="portal_state context/@@plone_portal_state" > The language is <span tal:content="portal_state/language" /> </div>
Use in templates and expressions¶
You can use
IPortalState in TALES
portal_actions, as well.
portal_actions conditional expression:
python:object.restrictedTraverse('@@plone_portal_state').language() == 'fi'
Tools are persistent utility classes available in the site root. They are visible in the Management Interface, and sometimes expose useful information or configuration here. Tools include e.g.:
Search and indexing facilities for content
Look up workflow status, and do workflow-related actions.
User registration information.
Get a portal tool using plone.api¶
It is recommended to use plone.api to get a portal tool:
from plone import api catalog = api.portal.get_tool(name='portal_catalog')
plone.api package exposes functionality from portal tools, it is not
longer necessary to directly call a tool. For example; the API can be used
the get the
change the workflow state,
get a member and
get the member properties.
plone.app.layout.globals.interfaces.ITools interface and Tools BrowserView provide cached access for the most commonly needed tools.
ITools is mapped as the
plone_tools view for traversing.
from Acquisition import aq_inner from zope.component import getMultiAdapter context = aq_inner(self.context) tools = getMultiAdapter((context, self.request), name=u'plone_tools') portal_url = tools.url() # The root URL of the site is got by using portal_url.__call__() # method the_current_root_url_of_the_site = portal_url()
Products.CMFPlone.browser.interfaces.IPlone provides some helper methods for Plone specific functionality and user interface.
IPlonehelper views is registered under the name
getToolByName is the old-fashioned way of getting tools,
using the context object as a starting point.
It also works for tools which do not implement the
getToolByName gets any Plone portal root item using acquisition.
from Products.CMFCore.WorkflowCore import WorkflowException # Do the workflow transition "submit" for the current context workflowTool = getToolByName(self.context, "portal_workflow") workflowTool.doActionFor(self.context, "submit")