Metadata-Version: 1.0
Name: grokcore.view
Version: 1.5
Summary: Grok-like configuration for Zope browser pages
Home-page: http://grok.zope.org
Author: Grok Team
Author-email: grok-dev@zope.org
License: ZPL
Download-URL: http://pypi.python.org/pypi/grok/
Description: This package provides support for writing browser pages for Zope
        and registering them directly in Python (without ZCML).
        
        .. contents::
        
        Setting up ``grokcore.view``
        ============================
        
        This package is essentially set up like the `grokcore.component`_
        package, please refer to its documentation for details.  The
        additional ZCML line you will need is::
        
        <include package="grokcore.view" file="meta.zcml" />
        <include package="grokcore.view" />
        
        Put the first line somewhere near the top of your root ZCML file (but
        below the line where you include ``grokcore.component``'s
        configuration) and the second line somewhere next to your other
        dependency includes.
        
        
        Examples
        ========
        
        Simple browser page
        -------------------
        
        A browser page is implemented by subclassing the
        ``grokcore.view.View`` baseclass.  At a minimum, a browser page must
        have
        
        1. either an associated template or a ``render()`` method
        
        2. a context that it's registered for as a view
        
        3. a name (which is, if not specified explicitly, the class's name in
        lower case characters).
        
        For example, the following class defines a view that's registered for
        all objects and simply prints "Hello World!"::
        
        import grokcore.view
        import zope.interface
        
        class Hello(grokcore.view.View):
        grokcore.view.context(zope.interface.Interface)
        
        def render(self):
        self.response.setHeader("Content-Type", "text/plain")
        return "Hello World!"
        
        Here we've made use of the implicit name feature.  This class will be
        available as the ``hello`` view for all objects.  So for instance,
        you'll be able to invoke it with URLs like::
        
        http://localhost/some/obj/hello
        
        We could also have spelled this out explicitly::
        
        class Hello(grokcore.view.View):
        grokcore.view.context(zope.interface.Interface)
        grokcore.view.name('hello')
        
        ...
        
        Browser page with template
        --------------------------
        
        Of course, more than often a view should render HTML which you would
        construct using some sort of templating engine.  ``grokcore.view``
        comes with built-in support for Zope's PageTemplate engine.  By
        convention, PageTemplate templates end with the ``.pt`` extension.
        
        So let our ``Hello`` view render HTML instead of plain text, we remove
        the ``render()`` method from the class and instead we create a
        template, e.g. like so::
        
        <html>
        <body>
        <p>Hello <span tal:replace="request/principal/title" />!</p>
        </body>
        </html>
        
        This will greet a logged in user with his or her actual name.
        
        To associate the template with the view, we have to put it in a
        certain place.  Let's say the ``Hello`` view class from above was in
        an ``app.py`` module.  Then we create an ``app_templates`` directory
        next to it and place the template file in there (the name of this
        directory can be customized with the ``templatedir`` directive, see
        below).  The file name can be anything as long as the extension is
        ``.pt``.  However, we can again make use of a convention here.  If we
        name the template like the class (except in lower case characters),
        then the template and the class are associated automatically.  If not,
        we would have to use the ``template`` directive on the view class to
        spell out the name of the template file explicitly.
        
        To cut a long story short, if we named it ``app_templates/hello.pt``,
        it would be found automatically.
        
        Static resources
        ----------------
        
        Browser pages often need additional static resources like CSS and JavaScript
        files. These can be conveniently placed into a directory called ``static`` in
        the package that contains the view code. When this directory exists it will
        automatically be registered as a resource directory. It then is available as
        the ``static`` variable in all views of this package and you can refer to files
        inside this directory like so::
        
        <img src="hello.png" tal:attributes="src static/hello.png" />
        
        DirectoryResource
        -----------------
        
        In addition to the very convenient "static resources", one can use more
        explicitly configured and flexible DirectoryResource components.
        DirectoryResource component allow for differentiating resources based on layers
        and names and provide a way to register resources in one package and make use
        of these resources in another package's views::
        
        class FooResource(grokcore.view.DirectoryResource):
        grokcore.view.path('foo')
        
        Or with an explicit name::
        
        class BarResource(grokcore.view.DirectoryResource):
        grokcore.view.name('bar')
        grokcore.view.path('bar')
        
        Registered for a layer::
        
        class BazResource(grokcore.view.DirectoryResource):
        grokcore.view.layer(ISomeLayer)
        grokcore.view.path('baz/qux')
        
        Layers and skins
        ----------------
        
        To define a browser layer, simply extend the ``IBrowserRequest``
        interface::
        
        class IGreenLayer(grokcore.view.IBrowserRequest):
        pass
        
        If you then wanted to define a skin, simply inherit from all the layer
        interfaces that should be in the skin and use the ``skin()`` directive
        to give the layer a name::
        
        class IGreenSkin(IGreenLayer, grokcore.view.IDefaultBrowserLayer):
        grokcore.view.skin('Green')
        
        To place a view on a layer, simply use the ``layer`` directive::
        
        class Hello(grokcore.view.View):
        grokcore.view.context(zope.interface.Interface)
        grokcore.view.layer(IGreenLayer)
        
        ...
        
        
        API overview
        ============
        
        Base classes
        ------------
        
        ``View``
        Base class for browser pages.  Use the ``context`` directive to
        specify the view's context.  Use the ``name`` directive to set the
        view's name; if not used, the view's name will be the class's name
        in lower case characters.  You may also use the ``template``
        directive to specify the name of the template file that should be
        associated with the view as well as the ``layer`` directive to
        specify which layer it should be on if not the default layer.
        
        View API
        --------
        
        ``grokcore.view.View`` is a regular Zope browser page, so it behaves
        exactly like a regular browser page from the outside.  It provides a
        bit more to the developer using it as a base class, though:
        
        ``context``
        The view's context object.  This can be discriminated by using the
        ``context`` directive on the view class.
        
        ``request``
        The request object, typically provides ``IBrowserRequest``.
        
        ``response``
        The response object, typically provides ``IHTTPResponse``.
        
        ``static``
        Directory resource representing the package's ``static`` directory or None
        if no such directory was found during grokking.
        
        ``redirect(url)``
        Redirect to the given URL.
        
        ``url(obj=None, name=None, data=None)``
        Constructs a URL:
        
        * If no arguments are given, the URL to the view itself is
        constructed.
        
        * If only the ``obj`` argument is given, the URL to that object is
        constructed.
        
        * If both ``obj`` and ``name`` arguments are supplied, construct
        the URL to the object and append ``name`` (presumably the name
        of a view).
        
        Optionally, ``data`` can be a dictionary whose contents is added to
        the URL as a query string.
        
        Methods for developers to implement:
        
        ``update(**kw)``
        This method will be called before the view's associated template
        is rendered.  If you therefore want to pre-compuate values for the
        template, implement this method.  You can save the values on
        ``self`` (the view object) and later access them through the
        ``view`` variable from the template.  The method can take
        arbitrary keyword parameters which are filled from request values.
        
        ``render(**kw)``
        Implement this method if (and only if) there isn't a template that
        goes with the view class.  Return either an encoded 8-bit string
        or a unicode string.  The method can take arbitrary keyword
        parameters which are filled from request values.
        
        
        Directives
        ----------
        
        ``templatedir(dirname)``
        Module-level directive that tells the template machinery which
        directory to look in for templates that should associated with
        views in a particular module.  If not used, it defaults to
        ``<module_name>_templates``.
        
        ``template(filename_wo_ext)``
        Class-level directive that specifies the name a template file
        that's associated with a view class, *without* the file extension.
        If not used, it defaults to the class's name in lower case
        characters.
        
        ``layer(layer_interface)``
        Class-level directive that defines which layer the view is
        registered on.  If not used, it defaults to the
        ``IDefaultBrowserLayer``.
        
        ``skin(skin_name)``
        Directive used on a layer interface to register it as skin using a
        human-readable name (``skin_name``).
        
        ``path(relative_or_absolute_path)``
        Directove used in a DirectoryResource registration to point to a non-
        package directory(hierarchy) containing resources like images, css files,
        etc.
        
        Other
        -----
        
        ``url(request, obj, name=None, data=None)``
        Generate the URL to an object, with an optional view name
        attached.  The ``data`` argument can be a dictionary whose
        contents is converted into the a query string that's appended to
        the URL.
        
        ``PageTemplate(template_code)``
        Create an inline PageTemplate object.
        
        ``PageTemplateFile(filename)``
        Create a PageTemplate object from a file.
        
        ``IBrowserRequest``
        Browser request interface from ``zope.publisher``.
        
        ``IDefaultBrowserLayer``
        Default layer for browser components from ``zope.publisher``.
        
        
        In addition, the ``grokcore.view`` package exposes the
        `grokcore.component`_ and `grokcore.security`_ APIs.
        
        .. _grokcore.component: http://pypi.python.org/pypi/grokcore.component
        .. _grokcore.security: http://pypi.python.org/pypi/grokcore.security
        .. _grokcore.view: http://pypi.python.org/pypi/grokcore.view
        
        Changes
        =======
        
        1.5 (2009-04-10)
        ----------------
        
        - Don't register a 'static' resource directory if the 'static' directory does
        not exist.
        
        - Make it possible to instantiate an ungrokked view by being slightly more
        defensive in __init__. This makes it easier to write unit tests.
        
        1.4 (2009-04-08)
        ----------------
        
        * Page template reloading now also works for macros. Fixes
        https://bugs.launchpad.net/grok/+bug/162261.
        
        * Use zope.container instead of zope.app.container.
        
        * Ignore '<tpl>.cache' files when looking up template files in a
        template dir. Fix bug https://bugs.launchpad.net/grok/+bug/332747
        
        1.3 (2009-01-28)
        ----------------
        
        * Adapt tests to work also from eggs not only source checkouts by
        avoiding `src` in directory comparisons.
        
        * Fix the factory for subdirectories of the DirectoryResource implementation
        by using hooks in zope.app.publisher.browser.directoryresource.
        
        * Update APIs interfaces to include the new ``path`` directive and
        new ``DirectoryResource`` component.
        
        1.2 (2008-10-16)
        ----------------
        
        * Expose the ``DirectoryResource`` class as a component for registering
        directories as resources. This is accompanied by the ``path`` directive that
        is used to point to the directory holding resources by way of an relative (to
        the module) or absolute path. ``DirectoryResource`` components can be
        differentiated by name and layer.
        
        1.1 (2008-09-22)
        ----------------
        
        * ``meta.py`` module containing the grokkers has been split in a
        package with separate modules for the view, template, skin and
        static resources grokkers. This allows applications to use only
        grokkers they need (and maybe redefine others).
        
        1.0 (2006-08-07)
        ----------------
        
        * Created ``grokcore.view`` in July 2008 by factoring security-related
        components, grokkers and directives out of Grok.
        
Platform: UNKNOWN
Classifier: Environment :: Web Environment
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: Zope Public License
Classifier: Programming Language :: Python
Classifier: Framework :: Zope3
