Merge pull request #2375 from stevepiercy/feature/alchemy-scaffold-update

update definingviews (done)

1 files changed, 130 insertions, 119 deletions

diff --git a/docs/tutorials/wiki2/definingviews.rst b/docs/tutorials/wiki2/definingviews.rst
index 184f9e1fa..e48980dc8 100644
--- a/docs/tutorials/wiki2/definingviews.rst
+++ b/docs/tutorials/wiki2/definingviews.rst
@@ -3,10 +3,10 @@ Defining Views
 ==============
 
 A :term:`view callable` in a :app:`Pyramid` application is typically a simple
-Python function that accepts a single parameter named :term:`request`.  A
-view callable is assumed to return a :term:`response` object.
+Python function that accepts a single parameter named :term:`request`. A view
+callable is assumed to return a :term:`response` object.
 
-The request object has a dictionary as an attribute named ``matchdict``.  A
+The request object has a dictionary as an attribute named ``matchdict``. A
 ``matchdict`` maps the placeholders in the matching URL ``pattern`` to the
 substrings of the path in the :term:`request` URL. For instance, if a call to
 :meth:`pyramid.config.Configurator.add_route` has the pattern ``/{one}/{two}``,
@@ -14,10 +14,11 @@ and a user visits ``http://example.com/foo/bar``, our pattern would be matched
 against ``/foo/bar`` and the ``matchdict`` would look like ``{'one':'foo',
 'two':'bar'}``.
 
+
 Adding the ``docutils`` dependency
 ==================================
 
-Remember in the previous chapter we added a new dependency on the ``bcrypt``
+Remember in the previous chapter we added a new dependency of the ``bcrypt``
 package. Again, the view code in our application will depend on a package which
 is not a dependency of the original "tutorial" application.
 
@@ -35,7 +36,8 @@ Open ``tutorial/setup.py`` and edit it to look like the following:
 Only the highlighted line needs to be added.
 
 Again, as we did in the previous chapter, the dependency now needs to be
-installed so re-run the ``python setup.py develop`` command.
+installed, so re-run the ``python setup.py develop`` command.
+
 
 Static assets
 -------------
@@ -46,52 +48,54 @@ were provided at the time we created the project.
 
 As an example, the CSS file will be accessed via
 ``http://localhost:6543/static/theme.css`` by virtue of the call to the
-``add_static_view`` directive we've made in the ``routes.py`` file.  Any
-number and type of static assets can be placed in this directory (or
-subdirectories) and are just referred to by URL or by using the convenience
-method ``static_url``, e.g.,
-``request.static_url('<package>:static/foo.css')`` within templates.
+``add_static_view`` directive we've made in the ``routes.py`` file. Any number
+and type of static assets can be placed in this directory (or subdirectories)
+and are just referred to by URL or by using the convenience method
+``static_url``, e.g., ``request.static_url('<package>:static/foo.css')`` within
+templates.
+
 
 Adding routes to ``routes.py``
 ==============================
 
-This is the URL Dispatch tutorial and so let's start by adding some
-URL patterns to our app. Later we'll attach views to handle the URLs.
+This is the `URL Dispatch` tutorial, so let's start by adding some URL patterns
+to our app. Later we'll attach views to handle the URLs.
 
-The ``routes.py`` file contains
-:meth:`pyramid.config.Configurator.add_route` calls which serve to add routes
-to our application.  First, we’ll get rid of the existing route created by
-the template using the name ``'home'``. It’s only an example and isn’t
-relevant to our application.
+The ``routes.py`` file contains :meth:`pyramid.config.Configurator.add_route`
+calls which serve to add routes to our application. First we'll get rid of the
+existing route created by the template using the name ``'home'``. It's only an
+example and isn't relevant to our application.
 
-We then need to add four calls to ``add_route``.  Note that the *ordering* of
-these declarations is very important.  ``route`` declarations are matched in
-the order they're registered.
+We then need to add four calls to ``add_route``. Note that the *ordering* of
+these declarations is very important. Route declarations are matched in the
+order they're registered.
 
-#. Add a declaration which maps the pattern ``/`` (signifying the root URL)
-   to the route named ``view_wiki``.  It maps to our ``view_wiki`` view
-   callable by virtue of the ``@view_config`` attached to the ``view_wiki``
-   view function indicating ``route_name='view_wiki'``.
+#. Add a declaration which maps the pattern ``/`` (signifying the root URL) to
+   the route named ``view_wiki``. In the next step, we will map it to our
+   ``view_wiki`` view callable by virtue of the ``@view_config`` decorator
+   attached to the ``view_wiki`` view function, which in turn will be indicated
+   by ``route_name='view_wiki'``.
 
 #. Add a declaration which maps the pattern ``/{pagename}`` to the route named
-   ``view_page``.  This is the regular view for a page.  It maps
-   to our ``view_page`` view callable by virtue of the ``@view_config``
-   attached to the ``view_page`` view function indicating
-   ``route_name='view_page'``.
+   ``view_page``. This is the regular view for a page. Again, in the next step,
+   we will map it to our ``view_page`` view callable by virtue of the
+   ``@view_config`` decorator attached to the ``view_page`` view function,
+   whin in turn will be indicated by ``route_name='view_page'``.
 
 #. Add a declaration which maps the pattern ``/add_page/{pagename}`` to the
-   route named ``add_page``.  This is the add view for a new page.  It maps
-   to our ``add_page`` view callable by virtue of the ``@view_config``
-   attached to the ``add_page`` view function indicating
-   ``route_name='add_page'``.
+   route named ``add_page``. This is the add view for a new page. We will map
+   it to our ``add_page`` view callable by virtue of the ``@view_config``
+   decorator attached to the ``add_page`` view function, which in turn will be
+   indicated by ``route_name='add_page'``.
 
 #. Add a declaration which maps the pattern ``/{pagename}/edit_page`` to the
-   route named ``edit_page``.  This is the edit view for a page.  It maps
+   route named ``edit_page``. This is the edit view for a page. We will map it
    to our ``edit_page`` view callable by virtue of the ``@view_config``
-   attached to the ``edit_page`` view function indicating
-   ``route_name='edit_page'``.
+   decorator attached to the ``edit_page`` view function, which in turn will be
+   indicated by ``route_name='edit_page'``.
 
-As a result of our edits, the ``routes.py`` file should look something like:
+As a result of our edits, the ``routes.py`` file should look like the
+following:
 
 .. literalinclude:: src/views/tutorial/routes.py
    :linenos:
@@ -103,13 +107,14 @@ The highlighted lines are the ones that need to be added or edited.
 .. warning::
 
    The order of the routes is important! If you placed
-   ``/{pagename}/edit_page`` **before** ``/add_page/{pagename}`` then we would
-   never be able to add pages because the first route would always match
-   a request to ``/add_page/edit_page`` whereas we want ``/add_page/..`` to
-   have priority. This isn't a huge problem in this particular app because
-   wiki pages are always camel case but it's important to be aware of this
+   ``/{pagename}/edit_page`` *before* ``/add_page/{pagename}``, then we would
+   never be able to add pages. This is because the first route would always
+   match a request to ``/add_page/edit_page`` whereas we want ``/add_page/..``
+   to have priority. This isn't a huge problem in this particular app because
+   wiki pages are always camel case, but it's important to be aware of this
    behavior in your own apps.
 
+
 Adding view functions in ``views/default.py``
 =============================================
 
@@ -131,23 +136,24 @@ and isn't relevant to our application.  We also deleted the ``db_err_msg``
 string.
 
 Then we added four :term:`view callable` functions to our ``views/default.py``
-module:
+module, as mentioned in the previous step:
 
 * ``view_wiki()`` - Displays the wiki itself. It will answer on the root URL.
 * ``view_page()`` - Displays an individual page.
-* ``add_page()`` - Allows the user to add a page.
 * ``edit_page()`` - Allows the user to edit a page.
+* ``add_page()`` - Allows the user to add a page.
 
 We'll describe each one briefly in the following sections.
 
 .. note::
 
-  There is nothing special about the filename ``default.py`` exept that
-  it is a Python module.  A project may have many view callables throughout
-  its codebase in arbitrarily named modules.
-  Modules implementing view callables often have ``view`` in their name (or
-  may live in a Python subpackage of your application package named ``views``,
-  as in our case), but this is only by convention, not a requirement.
+  There is nothing special about the filename ``default.py`` exept that it is a
+  Python module. A project may have many view callables throughout its codebase
+  in arbitrarily named modules. Modules implementing view callables often have
+  ``view`` in their name (or may live in a Python subpackage of your
+  application package named ``views``, as in our case), but this is only by
+  convention, not a requirement.
+
 
 The ``view_wiki`` view function
 -------------------------------
@@ -166,13 +172,14 @@ represents the path to our "FrontPage".
 
 The ``view_wiki`` view callable always redirects to the URL of a Page resource
 named "FrontPage".  To do so, it returns an instance of the
-:class:`pyramid.httpexceptions.HTTPFound` class (instances of which
-implement the :class:`pyramid.interfaces.IResponse` interface, like
-:class:`pyramid.response.Response` does). It uses the
+:class:`pyramid.httpexceptions.HTTPFound` class (instances of which implement
+the :class:`pyramid.interfaces.IResponse` interface, like
+:class:`pyramid.response.Response`). It uses the
 :meth:`pyramid.request.Request.route_url` API to construct a URL to the
 ``FrontPage`` page (i.e., ``http://localhost:6543/FrontPage``), and uses it as
 the "location" of the ``HTTPFound`` response, forming an HTTP redirect.
 
+
 The ``view_page`` view function
 -------------------------------
 
@@ -201,7 +208,7 @@ As a result, the ``content`` variable is now a fully formed bit of HTML
 containing various view and add links for WikiWords based on the content of
 our current page object.
 
-We then generate an edit URL because it's easier to do here than in the
+We then generate an edit URL, because it's easier to do here than in the
 template, and we return a dictionary with a number of arguments.  The fact that
 ``view_page()`` returns a dictionary (as opposed to a :term:`response` object)
 is a cue to :app:`Pyramid` that it should try to use a :term:`renderer`
@@ -209,22 +216,22 @@ associated with the view configuration to render a response.  In our case, the
 renderer used will be the ``view.jinja2`` template, as indicated in
 the ``@view_config`` decorator that is applied to ``view_page()``.
 
-If the page does not exist then we need to handle that by raising
-:class:`pyramid.httpexceptions.HTTPNotFound`` to trigger our 404 handling
+If the page does not exist, then we need to handle that by raising a
+:class:`pyramid.httpexceptions.HTTPNotFound` to trigger our 404 handling,
 defined in ``tutorial/views/notfound.py``.
 
 .. note::
 
-   Using ``raise`` versus ``return`` with the http exceptions is an important
+   Using ``raise`` versus ``return`` with the HTTP exceptions is an important
    distinction that can commonly mess people up. In
    ``tutorial/views/notfound.py`` there is an :term:`exception view`
-   registered for handling the ``HTTPNotFound`` exception. Exception views
-   are only triggered for raised exceptions. If the ``HTTPNotFound`` is
-   returned then it has an internal "stock" template that it will use
-   to render itself as a response. If you aren't seeing your exception
-   view being executed this is probably the problem! See
-   :ref:`special_exceptions_in_callables` for more information about
-   exception views.
+   registered for handling the ``HTTPNotFound`` exception. Exception views are
+   only triggered for raised exceptions. If the ``HTTPNotFound`` is returned,
+   then it has an internal "stock" template that it will use to render itself
+   as a response. If you aren't seeing your exception view being executed, this
+   is most likely the problem! See :ref:`special_exceptions_in_callables` for
+   more information about exception views.
+
 
 The ``edit_page`` view function
 -------------------------------
@@ -237,11 +244,11 @@ Here is the code for the ``edit_page`` view function and its decorator:
    :linenos:
    :language: python
 
-``edit_page()`` is invoked when a user clicks the "Edit this
-Page" button on the view form.  It renders an edit form, but it also acts as
-the handler for the form it renders.  The ``matchdict`` attribute of the
-request passed to the ``edit_page`` view will have a ``'pagename'`` key
-matching the name of the page the user wants to edit.
+``edit_page()`` is invoked when a user clicks the "Edit this Page" button on
+the view form. It renders an edit form, but it also acts as the handler for the
+form which it renders. The ``matchdict`` attribute of the request passed to the
+``edit_page`` view will have a ``'pagename'`` key matching the name of the page
+that the user wants to edit.
 
 If the view execution *is* a result of a form submission (i.e., the expression
 ``'form.submitted' in request.params`` is ``True``), the view grabs the
@@ -257,12 +264,13 @@ which will be used as the action of the generated form.
 .. note::
 
    Since our ``request.dbsession`` defined in the previous chapter is
-   registered with the ``pyramid_tm`` transaction manager any changes we make
-   to objects managed by the that session will be committed automatically.
-   In the event that there was an error (even later, in our template code) the
+   registered with the ``pyramid_tm`` transaction manager, any changes we make
+   to objects managed by the that session will be committed automatically. In
+   the event that there was an error (even later, in our template code), the
    changes would be aborted. This means the view itself does not need to
    concern itself with commit/rollback logic.
 
+
 The ``add_page`` view function
 ------------------------------
 
@@ -274,27 +282,26 @@ Here is the code for the ``add_page`` view function and its decorator:
    :linenos:
    :language: python
 
-``add_page()`` is invoked when a user clicks on a *WikiWord* which
-isn't yet represented as a page in the system.  The ``add_link`` function
-within the ``view_page`` view generates URLs to this view.
-``add_page()`` also acts as a handler for the form that is generated
-when we want to add a page object.  The ``matchdict`` attribute of the
-request passed to the ``add_page()`` view will have the values we need
-to construct URLs and find model objects.
+``add_page()`` is invoked when a user clicks on a *WikiWord* which isn't yet
+represented as a page in the system. The ``add_link`` function within the
+``view_page`` view generates URLs to this view. ``add_page()`` also acts as a
+handler for the form that is generated when we want to add a page object. The
+``matchdict`` attribute of the request passed to the ``add_page()`` view will
+have the values we need to construct URLs and find model objects.
 
-The ``matchdict`` will have a ``'pagename'`` key that matches the name of
-the page we'd like to add.  If our add view is invoked via,
-e.g., ``http://localhost:6543/add_page/SomeName``, the value for
-``'pagename'`` in the ``matchdict`` will be ``'SomeName'``.
+The ``matchdict`` will have a ``'pagename'`` key that matches the name of the
+page we'd like to add. If our add view is invoked via, for example,
+``http://localhost:6543/add_page/SomeName``, the value for ``'pagename'`` in
+the ``matchdict`` will be ``'SomeName'``.
 
 If the view execution *is* a result of a form submission (i.e., the expression
-``'form.submitted' in request.params`` is ``True``), we grab the page body
-from the form data, create a Page object with this page body and the name
-taken from ``matchdict['pagename']``, and save it into the database using
-``request.dbession.add``.  Since we have not yet covered authentication we
-don't have a logged-in user to add as the page's ``creator``. Until we
-get to that point in the tutorial we'll just assume that all pages are created
-by the ``editor`` user so we query that object and set it on ``page.creator``.
+``'form.submitted' in request.params`` is ``True``), we grab the page body from
+the form data, create a Page object with this page body and the name taken from
+``matchdict['pagename']``, and save it into the database using
+``request.dbession.add``. Since we have not yet covered authentication, we
+don't have a logged-in user to add as the page's ``creator``. Until we get to
+that point in the tutorial, we'll just assume that all pages are created by the
+``editor`` user. Thus we query for that object, and set it on ``page.creator``.
 Finally, we redirect the client back to the ``view_page`` view for the newly
 created page.
 
@@ -308,6 +315,7 @@ in order to satisfy the edit form's desire to have *some* page object
 exposed as ``page``. :app:`Pyramid` will render the template associated
 with this view to a response.
 
+
 Adding templates
 ================
 
@@ -317,25 +325,28 @@ These templates will live in the ``templates`` directory of our tutorial
 package.  Jinja2 templates must have a ``.jinja2`` extension to be recognized
 as such.
 
+
 The ``layout.jinja2`` template
 ------------------------------
 
-Replace ``tutorial/templates/layout.jinja2`` with the following content:
+Update ``tutorial/templates/layout.jinja2`` with the following content, as
+indicated by the emphasized lines:
 
 .. literalinclude:: src/views/tutorial/templates/layout.jinja2
    :linenos:
    :emphasize-lines: 11,36
    :language: html
 
-Since we're using a templating engine we can factor common boilerplate out of
-our page templates into reusable components. One method for doing this
-is template inheritance via blocks.
+Since we're using a templating engine, we can factor common boilerplate out of
+our page templates into reusable components. One method for doing this is
+template inheritance via blocks.
+
+- We have defined two placeholders in the layout template where a child
+  template can override the content. These blocks are named ``subtitle`` (line
+  11) and ``content`` (line 36).
+- Please refer to the Jinja2_ documentation for more information about template
+  inheritance.
 
-- We have defined 2 placeholders in the layout template where a child template
-  can override the content. These blocks are named ``subtitle`` (line 11) and
-  ``content`` (line 36).
-- Please refer to the Jinja2_ documentation for more information about
-  template inheritance.
 
 The ``view.jinja2`` template
 ----------------------------
@@ -344,23 +355,22 @@ Create ``tutorial/templates/view.jinja2`` and add the following content:
 
 .. literalinclude:: src/views/tutorial/templates/view.jinja2
    :linenos:
-   :emphasize-lines: 1,3,6
    :language: html
 
 This template is used by ``view_page()`` for displaying a single wiki page.
-It includes:
 
-- We begin by extending the ``layout.jinja2`` template defined above
-  which provides the skeleton of the page (line 1).
-- We override the ``subtitle`` block from the base layout to insert the
-  page name of the page into the page's title (line 3).
+- We begin by extending the ``layout.jinja2`` template defined above, which
+  provides the skeleton of the page (line 1).
+- We override the ``subtitle`` block from the base layout, inserting the page
+  name into the page's title (line 3).
 - We override the ``content`` block from the base layout to insert our markup
-  into the body (line 5-18).
-- A variable that is replaced with the ``content`` value provided by the view
-  (line 6).  ``content`` contains HTML, so the ``|safe`` filter is used to
+  into the body (lines 5-18).
+- We use a variable that is replaced with the ``content`` value provided by the
+  view (line 6). ``content`` contains HTML, so the ``|safe`` filter is used to
   prevent escaping it (e.g., changing ">" to "&gt;").
-- A link that points at the "edit" URL which invokes the ``edit_page`` view for
-  the page being viewed (line 9).
+- We create a link that points at the "edit" URL, which when clicked invokes
+  the ``edit_page`` view for the requested page (line 9).
+
 
 The ``edit.jinja2`` template
 ----------------------------
@@ -369,23 +379,23 @@ Create ``tutorial/templates/edit.jinja2`` and add the following content:
 
 .. literalinclude:: src/views/tutorial/templates/edit.jinja2
    :linenos:
-   :emphasize-lines: 3,12,14,17
+   :emphasize-lines: 1,3,12,14,17
    :language: html
 
-This template serves two use-cases. It is used by ``add_page()`` and
+This template serves two use cases. It is used by ``add_page()`` and
 ``edit_page()`` for adding and editing a wiki page.  It displays a page
-containing a form that includes:
+containing a form and which provides the following:
 
-- Again, we are extending the ``layout.jinja2`` template which provides
-  the skeleton of the page (line 1).
+- Again, we extend the ``layout.jinja2`` template, which provides the skeleton
+  of the page (line 1).
 - Override the ``subtitle`` block to affect the ``<title>`` tag in the
   ``head`` of the page (line 3).
 - A 10-row by 60-column ``textarea`` field named ``body`` that is filled with
   any existing page data when it is rendered (line 14).
 - A submit button that has the name ``form.submitted`` (line 17).
+- The form POSTs back to the ``save_url`` argument supplied by the view (line
+  12). The view will use the ``body`` and ``form.submitted`` values.
 
-The form POSTs back to the ``save_url`` argument supplied by the view (line
-12).  The view will use the ``body`` and ``form.submitted`` values.
 
 The ``404.jinja2`` template
 ---------------------------
@@ -419,9 +429,9 @@ There are several important things to note about this configuration:
   ``tutorial/views/default.py`` the exception is raised which will trigger
   the view.
 
-Finally, you may delete the ``tutorial/templates/mytemplate.jinja2``
-template that was provided by the ``alchemy`` scaffold as we have created
-our own templates for the wiki.
+Finally, we may delete the ``tutorial/templates/mytemplate.jinja2`` template
+that was provided by the ``alchemy`` scaffold, as we have created our own
+templates for the wiki.
 
 .. note::
 
@@ -431,6 +441,7 @@ our own templates for the wiki.
    See :ref:`renderer_system_values` for information about other names that
    are available by default when a template is used as a renderer.
 
+
 Viewing the application in a browser
 ====================================