3.zope:多适配器

#! /usr/bin/env python
#coding=utf-8

## 1 多适配

一个简单的适配器只适配一个对象，但一个适配器可适配多个对象。
如果一个适配器采用一个以上的对象，它被称为多适配器。

from zope.interface import Interface
from zope.interface import implements
from zope.component import adapts

class IAdapteeOne(Interface):
    pass

class IAdapteeTwo(Interface):
    pass

class IFunctionality(Interface):
    pass

#适配器
class MyFunctionality(object):
    #提供的接口
    implements(IFunctionality)
    #适配对象类
    adapts(IAdapteeOne, IAdapteeTwo)
    def __init__(self, one, two):
        self.one = one
        self.two = two

from zope.component import getGlobalSiteManager
gsm = getGlobalSiteManager()
gsm.registerAdapter(MyFunctionality)

class One(object):
    implements(IAdapteeOne)

class Two(object):
    implements(IAdapteeTwo)

one = One()
two = Two()

from zope.component import getMultiAdapter
print getMultiAdapter((one, two), IFunctionality) #doctest: +ELLIPSIS

myfunctionality = getMultiAdapter((one,two), IFunctionality)
print myfunctionality.one #doctest: +ELLIPSIS
print myfunctionality.two #doctest: +ELLIPSIS

#! /usr/bin/env python
#coding=utf-8

#2 订阅适配器

#适配器订阅时, 我们想要的所有适配器对象适配一个特定的接口。也被称为订阅者订阅适配器。
#考虑一个验证问题。我们有很多对象,我们想要评估这些对象是否符合某种标准。
#我们定义了一个验证接口

from zope.interface import Interface
from zope.interface import Attribute
from zope.interface import implements

class IValidate(Interface):
    def validate(ob):
        """ Determine whether the object is valid
            Return a string describing a validation problem.
            An empty string is returned to indicate that the
            object is valid.
        """

class IDocument(Interface):
    summary = Attribute("Document summary")
    body = Attribute("Document text")

class Document(object):
    implements(IDocument)
    def __init__(self, summary, body):
        self.summary, self.body = summary, body

from zope.component import adapts

#单行适配器
class SingleLineSummary:
    #是陪对象为提供IDocument接口的对象
    adapts(IDocument)
    implements(IValidate)
    def __init__(self, doc):
        self.doc = doc

    def validate(self):
        if '\n' in self.doc.summary:
            return 'Summary should only have one line'
        else:
            return ''

#长度适配器
class AdequateLength(object):
    adapts(IDocument)
    implements(IValidate)
    def __init__(self, doc):
        self.doc = doc

    def validate(self):
        if len(self.doc.body) < 1000:
            return 'too short'
        else:
            return ''

from zope.component import getGlobalSiteManager
gsm = getGlobalSiteManager()

#注册两个适配器
gsm.registerSubscriptionAdapter(SingleLineSummary)
gsm.registerSubscriptionAdapter(AdequateLength)

from zope.component import subscribers

#我们能够通过订阅者验证对象
doc = Document("A\nDocument", "blah")
print [adapter.validate() for adapter in subscribers([doc], IValidate) if adapter.validate()]

#['Summary should only have one line', 'too short']

doc = Document("A\nDocument", "blah" * 1000)
print [adapter.validate()
    for adapter in subscribers([doc], IValidate)
        if adapter.validate()]

#['Summary should only have one line']
doc = Document("A Document", "blah")
print [adapter.validate()
    for adapter in subscribers([doc], IValidate)
        if adapter.validate()]

#['too short']

#! /usr/bin/env python
#coding=utf-8

#3.处理器
#处理程序是订阅适配器不产生任何东东的工厂。当调用时,做所有的工作。
#处理程序通常用于处理事件。处理程序也被称为事件订阅者或事件订阅适配器。
#事件订阅者不同于其他订阅适配器的是：事件订阅者的访问者不希望任何直接的方式与之交互。
#例如,一个事件发布者不期望得到任何返回值。
#因为订阅者不需要给她的调用者提供一个API.他是更自然的函数定义而不是类。
#例如,在文档管理系统中,我们可能需要记录文件的创建时间:

import datetime


from zope.interface import Interface
from zope.interface import Attribute
from zope.interface import implements

class IDocumentCreated(Interface):
    doc = Attribute("The document that was created")

class DocumentCreated(object):
    implements(IDocumentCreated)
    def __init__(self, doc):
        self.doc = doc
        print self.doc

from zope.component import adapter

#作为渲染器
@adapter(IDocumentCreated)
def documentCreated(event):
    event.doc["b"] = datetime.datetime.utcnow()
    event.doc["c"] = "lallallllallallal"
    print event.doc

from zope.component import getGlobalSiteManager
gsm = getGlobalSiteManager()
gsm.registerHandler(documentCreated)

#我们可以创建一个事件和使用的处理函数调用注册为事件处理程序
from zope.component import handle
doc = {"a":1}
handle(DocumentCreated(doc))
print doc