Metadata-Version: 1.0
Name: z3c.template
Version: 1.2.0
Summary: A package implementing advanced Page Template patterns.
Home-page: http://pypi.python.org/pypi/z3c.template
Author: Roger Ineichen and the Zope Community
Author-email: zope-dev@zope.org
License: ZPL 2.1
Description: ------------
        Z3C template
        ------------
        
        This package allows you to register templates independently from view code.
        
        In Zope 3, when registering a `browser:page` both presentation and computation
        are registered together. Unfortunately the registration tangles presentation
        and computation so tightly that it is not possible to re-register a different
        template depending on context. (You can override the whole registration but
        this is not the main point of this package.)
        
        With z3c.template the registration is split up between the view and the
        template and allows to differentiate the template based on the skin layer and
        the view.
        
        In addition this package lays the foundation to differentiate between
        templates that provide specific presentation templates and generic layout
        templates.
        
        Detailed Documentation
        **********************
        
        =============
        Z3C Templates
        =============
        
        This package allows us to separate the registration of the view code and the
        layout.
        
        A template is used for separate the HTML part from a view. This is done in
        z3 via a page templates. Such page template are implemented in the view,
        registered included in a page directive etc. But they do not use the adapter
        pattern which makes it hard to replace existing templates.
        
        Another part of template is, that they normaly separate one part presenting
        content from a view and another part offer a layout used by the content
        template.
        
        How can this package make it simpler to use templates?
        
        Templates can be registered as adapters adapting context, request where the
        context is a view implementation. Such a template get adapted from the view
        if the template is needed. This adaption makes it very pluggable and modular.
        
        We offer two base template directive for register content producing templates
        and layout producing tempaltes. This is most the time enough but you also
        can register different type of templates using a specific interface. This
        could be usefull if your view implementation needs to separate HTMl in
        more then one template. Now let's take a look how we an use this templates.
        
        
        Content template
        ----------------
        
        First let's show how we use a template for produce content from a view:
        
        >>> import os, tempfile
        >>> temp_dir = tempfile.mkdtemp()
        >>> contentTemplate = os.path.join(temp_dir, 'contentTemplate.pt')
        >>> open(contentTemplate, 'w').write('''<div>demo content</div>''')
        
        And register a view class implementing a interface:
        
        >>> import zope.interface
        >>> from z3c.template import interfaces
        >>> from zope.pagetemplate.interfaces import IPageTemplate
        >>> from zope.publisher.browser import BrowserPage
        
        >>> class IMyView(zope.interface.Interface):
        ...     pass
        >>> class MyView(BrowserPage):
        ...     zope.interface.implements(IMyView)
        ...     template = None
        ...     def render(self):
        ...         if self.template is None:
        ...             template = zope.component.getMultiAdapter(
        ...                 (self, self.request), interfaces.IContentTemplate)
        ...             return template(self)
        ...         return self.template()
        
        Let's call the view and check the output:
        
        >>> from zope.publisher.browser import TestRequest
        >>> request = TestRequest()
        >>> view = MyView(root, request)
        
        Since the template is not yet registered, rendering the view will fail:
        
        >>> print view.render()
        Traceback (most recent call last):
        ...
        ComponentLookupError: ......
        
        Let's now register the template (commonly done using ZCML):
        
        >>> from zope import component
        >>> from zope.publisher.interfaces.browser import IDefaultBrowserLayer
        >>> from z3c.template.template import TemplateFactory
        
        The template factory allows us to create a ViewPageTeplateFile instance.
        
        >>> factory = TemplateFactory(contentTemplate, 'text/html')
        
        We register the factory on a view interface and a layer.
        
        >>> component.provideAdapter(
        ...     factory,
        ...     (zope.interface.Interface, IDefaultBrowserLayer),
        ...     interfaces.IContentTemplate)
        >>> template = component.getMultiAdapter((view, request),
        ...     interfaces.IPageTemplate)
        
        >>> from z3c.ptcompat import ViewPageTemplateFile
        >>> isinstance(template, ViewPageTemplateFile)
        True
        
        Now that we have a registered layout template for the default layer we can
        call our view again.
        
        >>> print view.render()
        <div>demo content</div>
        
        Now we register a new template on the specific interface of our view.
        
        >>> myTemplate = os.path.join(temp_dir, 'myTemplate.pt')
        >>> open(myTemplate, 'w').write('''<div>My content</div>''')
        >>> factory = TemplateFactory(myTemplate, 'text/html')
        >>> component.provideAdapter(
        ...     factory,
        ...     (IMyView, IDefaultBrowserLayer), interfaces.IContentTemplate)
        >>> print view.render()
        <div>My content</div>
        
        It is possible to provide the template directly.
        
        We create a new template.
        
        >>> viewContent = os.path.join(temp_dir, 'viewContent.pt')
        >>> open(viewContent, 'w').write('''<div>view content</div>''')
        
        and a view:
        
        >>> from z3c.ptcompat import ViewPageTemplateFile
        >>> class MyViewWithTemplate(BrowserPage):
        ...     zope.interface.implements(IMyView)
        ...     template = ViewPageTemplateFile(viewContent)
        ...     def render(self):
        ...         if self.template is None:
        ...             template = zope.component.getMultiAdapter(
        ...                 (self, self.request), interfaces.IContentTemplate)
        ...             return template(self)
        ...         return self.template()
        >>> contentView = MyViewWithTemplate(root, request)
        
        If we render this view we get the implemented layout template and not the
        registered one.
        
        >>> print contentView.render()
        <div>view content</div>
        
        
        Layout template
        ---------------
        
        First we nee to register a new view class calling a layout template. Note,
        that this view uses the __call__ method for invoke a layout template:
        
        >>> class ILayoutView(zope.interface.Interface):
        ...     pass
        >>> class LayoutView(BrowserPage):
        ...     zope.interface.implements(ILayoutView)
        ...     layout = None
        ...     def __call__(self):
        ...         if self.layout is None:
        ...             layout = zope.component.getMultiAdapter(
        ...                 (self, self.request), interfaces.ILayoutTemplate)
        ...             return layout(self)
        ...         return self.layout()
        >>> view2 = LayoutView(root, request)
        
        Define and register a new layout template:
        
        >>> layoutTemplate = os.path.join(temp_dir, 'layoutTemplate.pt')
        >>> open(layoutTemplate, 'w').write('''<div>demo layout</div>''')
        >>> factory = TemplateFactory(layoutTemplate, 'text/html')
        
        We register the template factory on a view interface and a layer providing the
        ILayoutTemplate interface.
        
        >>> component.provideAdapter(factory,
        ...     (zope.interface.Interface, IDefaultBrowserLayer),
        ...      interfaces.ILayoutTemplate)
        >>> layout = component.getMultiAdapter(
        ...     (view2, request), interfaces.ILayoutTemplate)
        
        >>> isinstance(layout, ViewPageTemplateFile)
        True
        
        Now that we have a registered layout template for the default layer we can
        call our view again.
        
        >>> print view2()
        <div>demo layout</div>
        
        Now we register a new layout template on the specific interface of our view.
        
        >>> myLayout = os.path.join(temp_dir, 'myLayout.pt')
        >>> open(myLayout, 'w').write('''<div>My layout</div>''')
        >>> factory = TemplateFactory(myLayout, 'text/html')
        >>> component.provideAdapter(factory,
        ...     (ILayoutView, IDefaultBrowserLayer),
        ...      interfaces.ILayoutTemplate)
        >>> print view2()
        <div>My layout</div>
        
        It is possible to provide the layout template directly.
        
        We create a new template.
        
        >>> viewLayout = os.path.join(temp_dir, 'viewLayout.pt')
        >>> open(viewLayout, 'w').write('''<div>view layout</div>''')
        
        >>> class LayoutViewWithLayoutTemplate(BrowserPage):
        ...     zope.interface.implements(ILayoutView)
        ...     layout = ViewPageTemplateFile(viewLayout)
        ...     def __call__(self):
        ...         if self.layout is None:
        ...             layout = zope.component.getMultiAdapter((self, self.request),
        ...                 interfaces.ILayoutTemplate)
        ...             return layout(self)
        ...         return self.layout()
        >>> layoutView = LayoutViewWithLayoutTemplate(root, request)
        
        If we render this view we get the implemented layout template and not the
        registered one.
        
        >>> print layoutView()
        <div>view layout</div>
        
        
        Since we return the layout template in the sample views above, how can we get
        the content from the used view? This is not directly a part of this package
        but let's show some pattern were can be used for render content in a used
        layout template. Note, since we offer to register each layout template for
        a specific view, you can always very selectiv this layout pattern. This means
        you can use the defualt z3 macro based layout registration in combination with
        this layout concept if you register a own layout template.
        
        The simplest concept is calling the content from the view in the layout
        template is to call it from a method. Let's define a view providing a layout
        template and offer a method for call content.
        
        >>> class IFullView(zope.interface.Interface):
        ...     pass
        
        >>> class FullView(BrowserPage):
        ...     zope.interface.implements(IFullView)
        ...     layout = None
        ...     def render(self):
        ...         return u'rendered content'
        ...     def __call__(self):
        ...         if self.layout is None:
        ...             layout = zope.component.getMultiAdapter((self, self.request),
        ...                 interfaces.ILayoutTemplate)
        ...             return layout(self)
        ...         return self.layout()
        >>> completeView = FullView(root, request)
        
        Now define a layout for the view and register them:
        
        >>> completeLayout = os.path.join(temp_dir, 'completeLayout.pt')
        >>> open(completeLayout, 'w').write('''
        ...   <div tal:content="view/render">
        ...     Full layout
        ...   </div>
        ... ''')
        
        >>> factory = TemplateFactory(completeLayout, 'text/html')
        >>> component.provideAdapter(factory,
        ...     (IFullView, IDefaultBrowserLayer), interfaces.ILayoutTemplate)
        
        Now let's see if the layout template can call the content via calling render
        on the view:
        
        >>> print completeView.__call__()
        <div>rendered content</div>
        
        
        Content and Layout
        ------------------
        
        Now let's show how we combine this two templates in a real use case:
        
        >>> class IDocumentView(zope.interface.Interface):
        ...     pass
        
        >>> class DocumentView(BrowserPage):
        ...     zope.interface.implements(IDocumentView)
        ...     template = None
        ...     layout = None
        ...     attr = None
        ...     def update(self):
        ...         self.attr = u'content updated'
        ...     def render(self):
        ...         if self.template is None:
        ...             template = zope.component.getMultiAdapter(
        ...                 (self, self.request), IPageTemplate)
        ...             return template(self)
        ...         return self.template()
        ...     def __call__(self):
        ...         self.update()
        ...         if self.layout is None:
        ...             layout = zope.component.getMultiAdapter((self, self.request),
        ...                 interfaces.ILayoutTemplate)
        ...             return layout(self)
        ...         return self.layout()
        
        Define and register a content template...
        
        >>> template = os.path.join(temp_dir, 'template.pt')
        >>> open(template, 'w').write('''
        ...   <div tal:content="view/attr">
        ...     here comes the value of attr
        ...   </div>
        ... ''')
        
        >>> factory = TemplateFactory(template, 'text/html')
        >>> component.provideAdapter(factory,
        ...     (IDocumentView, IDefaultBrowserLayer), IPageTemplate)
        
        and define and register a layout template:
        
        >>> layout = os.path.join(temp_dir, 'layout.pt')
        >>> open(layout, 'w').write('''
        ... <html>
        ...   <body>
        ...     <div tal:content="structure view/render">
        ...       here comes the rendered content
        ...     </div>
        ...   </body>
        ... </html>
        ... ''')
        
        >>> factory = TemplateFactory(layout, 'text/html')
        >>> component.provideAdapter(factory,
        ...     (IDocumentView, IDefaultBrowserLayer), interfaces.ILayoutTemplate)
        
        Now call the view and check the result:
        
        >>> documentView = DocumentView(root, request)
        >>> print documentView()
        <html>
        <body>
        <div>
        <div>content updated</div>
        </div>
        </body>
        </html>
        
        
        Macros
        ------
        
        Use of macros.
        
        >>> macroTemplate = os.path.join(temp_dir, 'macroTemplate.pt')
        >>> open(macroTemplate, 'w').write('''
        ...   <metal:block define-macro="macro1">
        ...     <div>macro1</div>
        ...   </metal:block>
        ...   <metal:block define-macro="macro2">
        ...     <div>macro2</div>
        ...     <div tal:content="options/div2">the content of div 2</div>
        ...   </metal:block>
        ...   ''')
        
        >>> factory = TemplateFactory(macroTemplate, 'text/html', 'macro1')
        >>> print factory(view, request)()
        <div>macro1</div>
        >>> m2factory = TemplateFactory(macroTemplate, 'text/html', 'macro2')
        >>> print m2factory(view, request)(div2="from the options")
        <div>macro2</div>
        <div>from the options</div>
        
        
        Why didn't we use named templates from the ``zope.formlib`` package?
        
        While named templates allow us to separate the view code from the template
        registration, they are not registrable for a particular layer making it
        impossible to implement multiple skins using named templates.
        
        
        Use case ``simple template``
        ----------------------------
        
        And for the simplest possible use we provide a hook for call registered
        templates. Such page templates can get called with the getPageTemplate method
        and return a registered bound ViewTemplate a la ViewPageTemplateFile or
        NamedTemplate.
        
        The getViewTemplate allows us to use the new template registration
        system with all existing implementations such as `zope.formlib` and
        `zope.viewlet`.
        
        >>> from z3c.template.template import getPageTemplate
        >>> class IUseOfViewTemplate(zope.interface.Interface):
        ...     pass
        >>> class UseOfViewTemplate(object):
        ...     zope.interface.implements(IUseOfViewTemplate)
        ...
        ...     template = getPageTemplate()
        ...
        ...     def __init__(self, context, request):
        ...         self.context = context
        ...         self.request = request
        
        By defining the "template" property as a "getPageTemplate" a lookup for
        a registered template is done when it is called.
        
        >>> simple = UseOfViewTemplate(root, request)
        >>> print simple.template()
        <div>demo content</div>
        
        Because the demo template was registered for any ("None") interface we see the
        demo template when rendering our new view. We register a new template
        especially for the new view. Also note that the "macroTemplate" has been
        created earlier in this test.
        
        >>> factory = TemplateFactory(contentTemplate, 'text/html')
        >>> component.provideAdapter(factory,
        ...     (IUseOfViewTemplate, IDefaultBrowserLayer), IPageTemplate)
        >>> print simple.template()
        <div>demo content</div>
        
        
        Context-specific templates
        --------------------------
        
        The ``TemplateFactory`` can be also used for (view, request, context)
        lookup. It's useful when you want to override a template for specific
        content object or type.
        
        Let's define a sample content type and instantiate a view for it.
        
        >>> class IContent(zope.interface.Interface):
        ...     pass
        >>> class Content(object):
        ...     zope.interface.implements(IContent)
        
        >>> content = Content()
        >>> view = UseOfViewTemplate(content, request)
        
        Now, let's provide a (view, request, context) adapter using TemplateFactory.
        
        >>> contextTemplate = os.path.join(temp_dir, 'context.pt')
        >>> open(contextTemplate, 'w').write('<div>context-specific</div>')
        >>> factory = TemplateFactory(contextTemplate, 'text/html')
        
        >>> component.provideAdapter(factory,
        ...     (IUseOfViewTemplate, IDefaultBrowserLayer, IContent),
        ...     interfaces.IContentTemplate)
        
        First. Let's try to simply get it as a multi-adapter.
        
        >>> template = zope.component.getMultiAdapter((view, request, content),
        ...                 interfaces.IContentTemplate)
        >>> print template(view)
        <div>context-specific</div>
        
        The ``getPageTemplate`` and friends will try to lookup a context-specific
        template before doing more generic (view, request) lookup, so our view
        should already use our context-specific template:
        
        >>> print view.template()
        <div>context-specific</div>
        
        
        Use case ``template by interface``
        ----------------------------------
        
        Templates can also get registered on different interfaces then IPageTemplate
        or ILayoutTemplate.
        
        >>> from z3c.template.template import getViewTemplate
        >>> class IMyTemplate(zope.interface.Interface):
        ...     """My custom tempalte marker."""
        
        >>> factory = TemplateFactory(contentTemplate, 'text/html')
        >>> component.provideAdapter(factory,
        ...     (zope.interface.Interface, IDefaultBrowserLayer), IMyTemplate)
        
        Now define a view using such a custom template registration:
        
        >>> class IMyTemplateView(zope.interface.Interface):
        ...     pass
        >>> class MyTemplateView(object):
        ...     zope.interface.implements(IMyTemplateView)
        ...
        ...     template = getViewTemplate(IMyTemplate)
        ...
        ...     def __init__(self, context, request):
        ...         self.context = context
        ...         self.request = request
        
        >>> myTempalteView = MyTemplateView(root, request)
        >>> print myTempalteView.template()
        <div>demo content</div>
        
        
        Use case ``named template``
        ----------------------------------
        
        Templates can also get registered on names. In this expample we use a named
        template combined with a custom template marker interface.
        
        >>> class IMyNamedTemplate(zope.interface.Interface):
        ...     """My custom template marker."""
        
        >>> factory = TemplateFactory(contentTemplate, 'text/html')
        >>> component.provideAdapter(factory,
        ...     (zope.interface.Interface, IDefaultBrowserLayer), IMyNamedTemplate,
        ...     name='my template')
        
        Now define a view using such a custom named template registration:
        
        >>> class IMyNamedTemplateView(zope.interface.Interface):
        ...     pass
        >>> class MyNamedTemplateView(object):
        ...     zope.interface.implements(IMyNamedTemplateView)
        ...
        ...     template = getViewTemplate(IMyNamedTemplate, 'my template')
        ...
        ...     def __init__(self, context, request):
        ...         self.context = context
        ...         self.request = request
        
        >>> myNamedTempalteView = MyNamedTemplateView(root, request)
        >>> print myNamedTempalteView.template()
        <div>demo content</div>
        
        
        Use case ``named layout template``
        ----------------------------------
        
        We can also register a new layout template by name and use it in a view:
        
        >>> from z3c.template.template import getLayoutTemplate
        
        >>> editLayout = os.path.join(temp_dir, 'editLayout.pt')
        >>> open(editLayout, 'w').write('''
        ...   <div>Edit layout</div>
        ...   <div tal:content="view/render">content</div>
        ... ''')
        >>> factory = TemplateFactory(editLayout, 'text/html')
        >>> component.provideAdapter(factory,
        ...     (zope.interface.Interface, IDefaultBrowserLayer),
        ...      interfaces.ILayoutTemplate, name='edit')
        
        Now define a view using such a custom named template registration:
        
        >>> class MyEditView(BrowserPage):
        ...
        ...     layout = getLayoutTemplate('edit')
        ...
        ...     def render(self):
        ...         return u'edit content'
        ...
        ...     def __call__(self):
        ...         if self.layout is None:
        ...             layout = zope.component.getMultiAdapter((self, self.request),
        ...                 interfaces.ILayoutTemplate)
        ...             return layout(self)
        ...         return self.layout()
        
        >>> myEditView = MyEditView(root, request)
        >>> print myEditView()
        <div>Edit layout</div>
        <div>edit content</div>
        
        
        Cleanup
        -------
        
        >>> import shutil
        >>> shutil.rmtree(temp_dir)
        
        
        Pagelet
        -------
        
        See z3c.pagelet for another template based layout generating implementation.
        
        =======
        CHANGES
        =======
        
        1.2.0 (2009-02-26)
        ------------------
        
        * Add support for context-specific templates. Now, templates can be
        registered and looked up using (view, request, context) triple.
        To do that, pass the ``context`` argument to the ZCML directives.
        The ``getPageTemplate`` and friends will now try to lookup context
        specific template first and then fall back to (view, request) lookup.
        
        * Allow use of ``z3c.pt`` using ``z3c.ptcompat`` compatibility layer.
        
        * Forward the template kwargs to the options of the macro
        
        * Changed package's mailing list address to zope-dev at zope.org
        instead of retired one.
        
        1.1.0 (2007-10-08)
        ------------------
        
        * Added an ``IContentTemplate`` interface which is used for
        ``<z3c:template>``.
        
        1.0.0 (2007-??-??)
        ------------------
        
        * Initial release.
        
Keywords: zope3 template layout zpt pagetemplate
Platform: UNKNOWN
Classifier: Development Status :: 5 - Production/Stable
Classifier: Environment :: Web Environment
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: Zope Public License
Classifier: Programming Language :: Python
Classifier: Natural Language :: English
Classifier: Operating System :: OS Independent
Classifier: Topic :: Internet :: WWW/HTTP
Classifier: Framework :: Zope3
