Sync views.py on SQL wiki tutorial with the scaffold

- Explain the added lines in the Basic Layout chapter.

- The user is told to remove the added lines in the
  Defining Views chapter, there was no need to fix
  any emphasized lines.

- Sync the file in the other sections even if it is not
  shown, for consistency.

4 files changed, 59 insertions, 10 deletions

diff --git a/docs/tutorials/wiki2/basiclayout.rst b/docs/tutorials/wiki2/basiclayout.rst
index dbd130c36..4f73dc914 100644
--- a/docs/tutorials/wiki2/basiclayout.rst
+++ b/docs/tutorials/wiki2/basiclayout.rst
@@ -171,6 +171,12 @@ application.  Without being processed by ``scan``, the decorator effectively
 does nothing.  ``@view_config`` is inert without being detected via a
 :term:`scan`.
 
+The sample ``my_view()`` created by the scaffold uses a ``try:`` and ``except:``
+clause, to detect if there is a problem accessing the project database and
+provide an alternate error response.  That response will include the text
+shown at the end of the file, which will be displayed in the browser to
+inform the user about possible actions to take to solve the problem.
+
 Content Models with ``models.py``
 ---------------------------------
 
diff --git a/docs/tutorials/wiki2/src/basiclayout/tutorial/views.py b/docs/tutorials/wiki2/src/basiclayout/tutorial/views.py
index 3e6abf2c2..daf21bb7b 100644
--- a/docs/tutorials/wiki2/src/basiclayout/tutorial/views.py
+++ b/docs/tutorials/wiki2/src/basiclayout/tutorial/views.py
@@ -1,5 +1,8 @@
+from pyramid.response import Response
 from pyramid.view import view_config
 
+from sqlalchemy.exc import DBAPIError
+
 from .models import (
     DBSession,
     MyModel,
@@ -7,5 +10,25 @@ from .models import (
 
 @view_config(route_name='home', renderer='templates/mytemplate.pt')
 def my_view(request):
-    one = DBSession.query(MyModel).filter(MyModel.name=='one').first()
+    try:
+        one = DBSession.query(MyModel).filter(MyModel.name=='one').first()
+    except DBAPIError:
+        return Response(conn_err_msg, content_type='text/plain', status_int=500)
     return {'one':one, 'project':'tutorial'}
+
+conn_err_msg = """\
+Pyramid is having a problem using your SQL database.  The problem
+might be caused by one of the following things:
+
+1.  You may need to run the "initialize_tutorial_db" script
+    to initialize your database tables.  Check your virtual 
+    environment's "bin" directory for this script and try to run it.
+
+2.  Your database server may not be running.  Check that the
+    database server referred to by the "sqlalchemy.url" setting in
+    your "development.ini" file is running.
+
+After you fix the problem, please restart the Pyramid application to
+try it again.
+"""
+
diff --git a/docs/tutorials/wiki2/src/models/tutorial/views.py b/docs/tutorials/wiki2/src/models/tutorial/views.py
index 3e6abf2c2..daf21bb7b 100644
--- a/docs/tutorials/wiki2/src/models/tutorial/views.py
+++ b/docs/tutorials/wiki2/src/models/tutorial/views.py
@@ -1,5 +1,8 @@
+from pyramid.response import Response
 from pyramid.view import view_config
 
+from sqlalchemy.exc import DBAPIError
+
 from .models import (
     DBSession,
     MyModel,
@@ -7,5 +10,25 @@ from .models import (
 
 @view_config(route_name='home', renderer='templates/mytemplate.pt')
 def my_view(request):
-    one = DBSession.query(MyModel).filter(MyModel.name=='one').first()
+    try:
+        one = DBSession.query(MyModel).filter(MyModel.name=='one').first()
+    except DBAPIError:
+        return Response(conn_err_msg, content_type='text/plain', status_int=500)
     return {'one':one, 'project':'tutorial'}
+
+conn_err_msg = """\
+Pyramid is having a problem using your SQL database.  The problem
+might be caused by one of the following things:
+
+1.  You may need to run the "initialize_tutorial_db" script
+    to initialize your database tables.  Check your virtual 
+    environment's "bin" directory for this script and try to run it.
+
+2.  Your database server may not be running.  Check that the
+    database server referred to by the "sqlalchemy.url" setting in
+    your "development.ini" file is running.
+
+After you fix the problem, please restart the Pyramid application to
+try it again.
+"""
+
diff --git a/docs/tutorials/wiki2/src/tests/tutorial/views.py b/docs/tutorials/wiki2/src/tests/tutorial/views.py
index 42ac0eb7f..0d085b0e2 100644
--- a/docs/tutorials/wiki2/src/tests/tutorial/views.py
+++ b/docs/tutorials/wiki2/src/tests/tutorial/views.py
@@ -37,14 +37,13 @@ def view_wiki(request):
              permission='view')
 def view_page(request):
     pagename = request.matchdict['pagename']
-    session = DBSession()
-    page = session.query(Page).filter_by(name=pagename).first()
+    page = DBSession.query(Page).filter_by(name=pagename).first()
     if page is None:
         return HTTPNotFound('No such page')
 
     def check(match):
         word = match.group(1)
-        exists = session.query(Page).filter_by(name=word).all()
+        exists = DBSession.query(Page).filter_by(name=word).all()
         if exists:
             view_url = request.route_url('view_page', pagename=word)
             return '<a href="%s">%s</a>' % (view_url, word)
@@ -63,10 +62,9 @@ def view_page(request):
 def add_page(request):
     pagename = request.matchdict['pagename']
     if 'form.submitted' in request.params:
-        session = DBSession()
         body = request.params['body']
         page = Page(pagename, body)
-        session.add(page)
+        DBSession.add(page)
         return HTTPFound(location = request.route_url('view_page',
                                                       pagename=pagename))
     save_url = request.route_url('add_page', pagename=pagename)
@@ -78,11 +76,10 @@ def add_page(request):
              permission='edit')
 def edit_page(request):
     pagename = request.matchdict['pagename']
-    session = DBSession()
-    page = session.query(Page).filter_by(name=pagename).one()
+    page = DBSession.query(Page).filter_by(name=pagename).one()
     if 'form.submitted' in request.params:
         page.data = request.params['body']
-        session.add(page)
+        DBSession.add(page)
         return HTTPFound(location = request.route_url('view_page',
                                                       pagename=pagename))
     return dict(