grokcore.message 4.0

Setting up grokcore.message

When being grokked, grokcore.message registers

• a global session message source named session

• a global message receiver.

Grokking of this package happens when the local configure.zcml is executed. In standard Grok-based packages this often happens automatically.

One can, of course, also grok the package manually:

>>> import grokcore.component as grok
>>> grok.testing.grok('grokcore.message')

This setups a global message receiver:

>>> from z3c.flashmessage.interfaces import IMessageReceiver
>>> from zope.component import getUtility
>>> getUtility(IMessageReceiver)
<z3c.flashmessage.receiver.GlobalMessageReceiver object at 0x...>

It also setups a session-based message source named session:

>>> from z3c.flashmessage.interfaces import IMessageSource
>>> getUtility(IMessageSource, name=u'session')
<z3c.flashmessage.sources.SessionMessageSource object at 0x...>

We provide also a RAM-stored message source that can be enabled by including ram.zcml and is not registered by default:

>>> getUtility(IMessageSource, name=u'ram')
Traceback (most recent call last):
...
zope.interface.interfaces.ComponentLookupError: (<InterfaceClass z3c.flashmessage.interfaces.IMessageSource>, 'ram')

You can enable this source by including ram.zcml from grokcore.message in your ZCML setup like this:

<configure xmlns="http://namespaces.zope.org/zope">
  <include package="grokcore.message" file="ram.zcml" />
</configure>

or, of course, by registering a RAMMessageSource manually:

>>> from zope.component import provideUtility
>>> from z3c.flashmessage.sources import RAMMessageSource
>>> ram_source = RAMMessageSource()
>>> provideUtility(ram_source, name=u'ram')

Now we can get the RAM source:

>>> getUtility(IMessageSource, name=u'ram')
<z3c.flashmessage.sources.RAMMessageSource object at 0x...>

Components (API)

grokcore.message provides some extra-components and functions beside the usual components from z3c.flashmessage.

Examples

Creating a UniqueMessageSource:

>>> from grokcore.message import UniqueMessageSource
>>> class MyUniqueMessageSource(UniqueMessageSource):
...   grok.name('uniq_source')

After being grokked, the source is automatically registered:

>>> grok.testing.grok_component(
...     'MyUniqueMessageSource', MyUniqueMessageSource,
...     dotted_name='grokcore.message.tests')
True

>>> source = getUtility(IMessageSource, name='uniq_source')
>>> source
<...MyUniqueMessageSource object at 0x...>

It provides the methods required by the IMessageSource interface:

>>> from z3c.flashmessage.interfaces import IMessageSource
>>> from zope.interface import verify

>>> verify.verifyClass(IMessageSource, MyUniqueMessageSource)
True

We can list the message stored in the source:

>>> source.list()
<generator object ...>

>>> list(source.list())
[]

>>> source.send(message='Hello!', type='message')
>>> list(source.list())
[<z3c.flashmessage.message.PersistentMessage object at 0x...>]

>>> print(list(source.list())[0].message)
Hello!

When we send another message, the old one will be silenty discarded:

>>> source.send(message='Hello again!', type='message')
>>> len(list(source.list()))
1

>>> print(list(source.list())[0].message)
Hello again!

We can delete the message:

>>> msg = list(source.list())[0]
>>> source.delete(msg)
>>> len(list(source.list()))
0

Examples for the convenience functions can be found above.

4.0 (2023-08-28)

• Drop support for Python 2.7, 3.4, 3.5, 3.6.

• Add support for Python 3.7, 3.8, 3.9, 3.10, 3.11.

3.0.1 (2018-01-17)

• Replace the use of grok.implements() with the @grok.implementer() directive throughout.

3.0.0 (2018-01-15)

• Python 3 compatibility.

0.4.3 (2016-02-15)

• Update tests.

0.4.2 (2010-10-25)

• Tests fixed by explicitely registering the IClientIdManager and ISessionDataContainer utilities. The ftesting.zcml was re-introduced for this.

0.4.1 (2010-10-25)

• Remove ftesting.zcml that was not necessary anymore.

0.4 (2010-10-25)

• Make sure zope.session is configured, as this package claims to provide for a session based flash message machinery.

• Made package comply to zope.org repository policy.

0.3 (2010-03-05)

• UniqueMessageSource now implements the IMessageSource interface completely, i.e. the type parameter is now optional when using UniqueMessageSource.send().

0.2 (2010-03-03)

• The utility function send now takes a name argument, allowing the choice of the target message source.

0.1 (2010-03-03)

• Factored out from former versions of grokui.admin, grok and megrok.layout respectively.