[Checkins] SVN: grok/branches/luciano-tutorial/doc/ introduced
Pebbles application example and refactored tutorial chapters
and samples from storing data to containers
Luciano Ramalho
luciano at ramalho.org
Thu Jul 12 21:53:38 EDT 2007
Log message for revision 77789:
introduced Pebbles application example and refactored tutorial chapters and samples from storing data to containers
Changed:
A grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/
A grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/__init__.py
A grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app.py
A grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app_templates/
A grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app_templates/giftindex.pt
A grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app_templates/index.pt
A grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/configure.zcml
D grok/branches/luciano-tutorial/doc/groktut/containers/src/sample/
D grok/branches/luciano-tutorial/doc/groktut/explicitly_associating_a_view_with_a_model/
A grok/branches/luciano-tutorial/doc/groktut/redirection/src/pebbles/
U grok/branches/luciano-tutorial/doc/groktut/redirection/src/pebbles/app.py
U grok/branches/luciano-tutorial/doc/groktut/redirection/src/pebbles/app_templates/index.pt
U grok/branches/luciano-tutorial/doc/groktut/storing_data/setup.py
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/__init__.py
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app.py
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app_templates/
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app_templates/edit.pt
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app_templates/index.pt
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/configure.zcml
D grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/sample/
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/__init__.py
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app.py
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app_templates/
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app_templates/edit.pt
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app_templates/index.pt
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/configure.zcml
D grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/sample/
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/__init__.py
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app.py
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app_templates/
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app_templates/edit.pt
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app_templates/index.pt
A grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/configure.zcml
D grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/sample/
U grok/branches/luciano-tutorial/doc/tutorial.txt
-=-
Added: grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/__init__.py
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/__init__.py (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/__init__.py 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1 @@
+#
Added: grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app.py
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app.py (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app.py 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,26 @@
+import grok
+
+class Pebbles(grok.Application, grok.Container):
+
+ def receive(self, source, quantity):
+ self[source] = Entry(source, quantity)
+
+
+class Index(grok.View):
+ grok.context(Pebbles)
+
+ def update(self, source=None, quantity=0):
+ if description is None:
+ return
+ self.context.receive(source, quantity)
+ self.redirect(self.url('index'))
+
+
+class Gift(grok.Model):
+ def __init__(self, source, quantity):
+ self.source = source
+ self.quantity = quantity
+
+class GiftIndex(grok.View):
+ grok.context(Gift)
+ grok.name('index')
Added: grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app_templates/giftindex.pt
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app_templates/giftindex.pt (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app_templates/giftindex.pt 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,8 @@
+<html>
+<head>
+</head>
+<body>
+ <h2>Gift from <span tal:replace="python:context.__name__"></span></h2>
+ <p><span tal:replace="context/quantity">999</span> stones.</p>
+</body>
+</html>
Added: grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app_templates/index.pt
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app_templates/index.pt (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/app_templates/index.pt 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,21 @@
+<html>
+<head>
+</head>
+<body>
+ <h2>Existing gifts</h2>
+ <ul>
+ <li tal:repeat="key context/keys">
+ <a tal:attributes="href python:view.url(key)"
+ tal:content="key"></a>
+ </li>
+ </ul>
+
+ <h2>Receive a gift</h2>
+ <form tal:attributes="action view/url" method="POST">
+ Name: <input type="text" name="source" value="" /><br />
+ Text: <input type="text" name="quantity" value="" /><br />
+ <input type="submit" value="Add gift" />
+ </form>
+
+</body>
+</html>
Added: grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/configure.zcml
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/configure.zcml (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/containers/src/pebbles/configure.zcml 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,5 @@
+<configure xmlns="http://namespaces.zope.org/zope"
+ xmlns:grok="http://namespaces.zope.org/grok">
+ <include package="grok" />
+ <grok:grok package="." />
+</configure>
Copied: grok/branches/luciano-tutorial/doc/groktut/redirection/src/pebbles (from rev 77787, grok/branches/luciano-tutorial/doc/groktut/storing_data/src/pebbles)
Modified: grok/branches/luciano-tutorial/doc/groktut/redirection/src/pebbles/app.py
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/storing_data/src/pebbles/app.py 2007-07-12 20:11:56 UTC (rev 77787)
+++ grok/branches/luciano-tutorial/doc/groktut/redirection/src/pebbles/app.py 2007-07-13 01:53:36 UTC (rev 77789)
@@ -10,4 +10,5 @@
def update(self, quantity=None):
if quantity is None:
return
- self.context.quantity = quantity
\ No newline at end of file
+ self.context.quantity = quantity
+ self.redirect(self.url('index'))
\ No newline at end of file
Modified: grok/branches/luciano-tutorial/doc/groktut/redirection/src/pebbles/app_templates/index.pt
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/storing_data/src/pebbles/app_templates/index.pt 2007-07-12 20:11:56 UTC (rev 77787)
+++ grok/branches/luciano-tutorial/doc/groktut/redirection/src/pebbles/app_templates/index.pt 2007-07-13 01:53:36 UTC (rev 77789)
@@ -4,5 +4,7 @@
<body>
<p>The quantity: <span tal:replace="python:context.quantity">999</span></p>
+ <p><a tal:attributes="href python:view.url('edit')">Edit this page</a></p>
+
</body>
</html>
Modified: grok/branches/luciano-tutorial/doc/groktut/storing_data/setup.py
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/storing_data/setup.py 2007-07-12 21:29:20 UTC (rev 77788)
+++ grok/branches/luciano-tutorial/doc/groktut/storing_data/setup.py 2007-07-13 01:53:36 UTC (rev 77789)
@@ -2,7 +2,7 @@
version = 0.0
-setup(name='Sample',
+setup(name='Pebbles',
version=version,
description="",
long_description="""\
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/__init__.py
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/__init__.py (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/__init__.py 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1 @@
+#
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app.py
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app.py (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app.py 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,17 @@
+import grok
+
+class Pebbles(grok.Application, grok.Container):
+ def __init__(self):
+ super(Pebbles, self).__init__()
+ self.gifts = []
+
+class Index(grok.View):
+ pass
+
+class Edit(grok.View):
+ def update(self, text=None):
+ if text is None:
+ return
+ # this code has a BUG!
+ self.context.incomes.append(text)
+ self.redirect(self.url('index'))
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app_templates/edit.pt
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app_templates/edit.pt (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app_templates/edit.pt 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,8 @@
+<html>
+<body>
+<form tal:attributes="action view/url" method="POST">
+Quantity to remember: <input type="text" name="quantity" value="" /><br />
+<input type="submit" value="Store" />
+</form>
+</body>
+</html>
\ No newline at end of file
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app_templates/index.pt
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app_templates/index.pt (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/app_templates/index.pt 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,9 @@
+<html>
+<body>
+We store the following quantities:
+<ul>
+ <li tal:repeat="qty python:context.gifts" tal:content="qty"></li>
+</ul>
+<a tal:attributes="href python:view.url('edit')">Add a number</a>
+</body>
+</html>
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/configure.zcml
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/configure.zcml (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence/src/pebbles/configure.zcml 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,5 @@
+<configure xmlns="http://namespaces.zope.org/zope"
+ xmlns:grok="http://namespaces.zope.org/grok">
+ <include package="grok" />
+ <grok:grok package="." />
+</configure>
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/__init__.py
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/__init__.py (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/__init__.py 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1 @@
+#
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app.py
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app.py (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app.py 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,18 @@
+import grok
+
+class Pebbles(grok.Application, grok.Container):
+ def __init__(self):
+ super(Pebbles, self).__init__()
+ self.gifts = []
+
+class Index(grok.View):
+ pass
+
+class Edit(grok.View):
+ def update(self, quantity=None):
+ if quantity is None:
+ return
+ # this code has a BUG!
+ self.context.incomes.append(quantity)
+ self.context._p_changed = True
+ self.redirect(self.url('index'))
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app_templates/edit.pt
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app_templates/edit.pt (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app_templates/edit.pt 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,8 @@
+<html>
+<body>
+<form tal:attributes="action view/url" method="POST">
+Quantity to remember: <input type="text" name="quantity" value="" /><br />
+<input type="submit" value="Store" />
+</form>
+</body>
+</html>
\ No newline at end of file
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app_templates/index.pt
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app_templates/index.pt (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/app_templates/index.pt 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,9 @@
+<html>
+<body>
+We store the following quantities:
+<ul>
+ <li tal:repeat="qty python:context.gifts" tal:content="qty"></li>
+</ul>
+<a tal:attributes="href python:view.url('edit')">Add a number</a>
+</body>
+</html>
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/configure.zcml
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/configure.zcml (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence2/src/pebbles/configure.zcml 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,5 @@
+<configure xmlns="http://namespaces.zope.org/zope"
+ xmlns:grok="http://namespaces.zope.org/grok">
+ <include package="grok" />
+ <grok:grok package="." />
+</configure>
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/__init__.py
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/__init__.py (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/__init__.py 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1 @@
+#
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app.py
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app.py (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app.py 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,20 @@
+import grok
+
+class Pebbles(grok.Application, grok.Container):
+ def __init__(self):
+ super(Pebbles, self).__init__()
+ self.gifts = []
+
+ def addGift(self, quantity):
+ self.gifts.append(quantity)
+ self._p_changed = True
+
+class Index(grok.View):
+ pass
+
+class Edit(grok.View):
+ def update(self, text=None):
+ if text is None:
+ return
+ self.context.addGift(quantity)
+ self.redirect(self.url('index'))
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app_templates/edit.pt
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app_templates/edit.pt (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app_templates/edit.pt 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,8 @@
+<html>
+<body>
+<form tal:attributes="action view/url" method="POST">
+Quantity to remember: <input type="text" name="quantity" value="" /><br />
+<input type="submit" value="Store" />
+</form>
+</body>
+</html>
\ No newline at end of file
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app_templates/index.pt
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app_templates/index.pt (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/app_templates/index.pt 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,9 @@
+<html>
+<body>
+We store the following quantities:
+<ul>
+ <li tal:repeat="qty python:context.gifts" tal:content="qty"></li>
+</ul>
+<a tal:attributes="href python:view.url('edit')">Add a number</a>
+</body>
+</html>
Added: grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/configure.zcml
===================================================================
--- grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/configure.zcml (rev 0)
+++ grok/branches/luciano-tutorial/doc/groktut/the_rules_of_persistence3/src/pebbles/configure.zcml 2007-07-13 01:53:36 UTC (rev 77789)
@@ -0,0 +1,5 @@
+<configure xmlns="http://namespaces.zope.org/zope"
+ xmlns:grok="http://namespaces.zope.org/grok">
+ <include package="grok" />
+ <grok:grok package="." />
+</configure>
Modified: grok/branches/luciano-tutorial/doc/tutorial.txt
===================================================================
--- grok/branches/luciano-tutorial/doc/tutorial.txt 2007-07-12 21:29:20 UTC (rev 77788)
+++ grok/branches/luciano-tutorial/doc/tutorial.txt 2007-07-13 01:53:36 UTC (rev 77789)
@@ -350,6 +350,16 @@
If you view that URL in your browser, you should see the same result
as before. This is the way all other, non-index views are accessed.
+.. sidebar: How does Grok know that a view belongs to a model?
+
+ In these simple examples, Grok makes this association automatically
+ because there is only a single model defined in the module
+ (``Sample``). In this case, Grok is clever enough to automatically
+ associate all views defined in the same module to the only
+ model. Behind the scenes Grok made the model the *context* of the
+ views. Later we will see how to make explicit view-model
+ associations when we have multiple models and views in a module.
+
Often, your application needs more than one view. A document for
instance may have an ``index`` view that displays it, but another
``edit`` view to change its contents. To create a second view, create
@@ -909,59 +919,69 @@
application object is stored in the object database, so we can store
some information on it.
-Let's create an application that stores a bit of text for us. We will
-use one view to view the text (``index``) and another to edit it
-(``edit``).
+Let's create a primitive application that stores a number for us. We will call it ``Pebbles``, after the computing devices used by cavemen. We will use one view to view the number (``index``) and another to edit it (``edit``). Use ``grokproject`` to create a new application called ``Pebbles``, then modify it's ``app.py`` to read like this:
-Modify ``app.py`` to read like this:
-
-.. include:: groktut/storing_data/src/sample/app.py
+.. include:: groktut/storing_data/src/pebbles/app.py
:literal:
-The ``Sample`` class gained a class attribute with some default text.
+The ``Pebbles`` class gained a class attribute with some default number.
In the ``update`` method of the ``Edit`` view you can see we actually
-set the ``text`` attribute on the context, if at least a ``text``
-value was supplied by a form. This will set the ``text`` attribute on
-the instance of the ``Sample`` object in the object database, and thus
-will override the default ``text`` class attribute.
+set the ``quantity`` attribute on the context, if a ``quantity``
+value was supplied by a form. This will set the ``quantity`` attribute on
+the instance of the ``Pebbles`` object in the object database, and thus
+will override the default ``quantity`` class attribute.
Change the ``index.pt`` template to read like this:
-.. include:: groktut/storing_data/src/sample/app_templates/index.pt
+.. include:: groktut/storing_data/src/pebbles/app_templates/index.pt
:literal:
-This is a very simple template that just displays the ``text``
-attribute of the ``context`` object (our ``Sample`` instance).
+This is a very simple template that just displays the ``quantity``
+attribute of the ``context`` object (our ``Pebbles`` instance).
Create an ``edit.pt`` template with the following content:
-.. include:: groktut/storing_data/src/sample/app_templates/edit.pt
+.. include:: groktut/storing_data/src/pebbles/app_templates/edit.pt
:literal:
-This template display a form asking for a bit of text. It submits to
+This template displays a form asking for a number. It submits to
itself.
Restart Zope. Let's first view the index page:
http://localhost:8080/test
-You should see ``default text``.
+You should see ``0``.
Now let's modify the text by going to the edit page of the application:
http://localhost:8080/test/edit
-Type in some text and press the "Store" button. Since it submits to
+Type in some number and press the "Store" button. Since it submits to
itself, we will see the form again, so go to the index page manually:
http://localhost:8080/test
-You should now see the text you just entered on the page. This means
-that your text was successfully stored in the object database!
+You should now see the number you just entered on the page. This means
+that your number was successfully stored in the object database!
-You can even restart Zope and go back to the index page, and your text
+You can even restart Zope and go back to the index page, and your number
should still be there.
+Showing the value in the form
+-----------------------------
+
+Let's change our application so it displays what we stored in the edit
+form as well, not just on the index page.
+
+To make this work, change edit.pt so it reads like this:
+
+.. include:: groktut/showing_the_value_in_the_form/src/pebbles/app_templates/edit.pt
+ :literal:
+
+The only change is that we have used ``tal:attributes`` to include the
+value of the ``quantity`` attribute of the context object in the form.
+
Redirection
-----------
@@ -969,7 +989,7 @@
``index.pt`` so it includes a link to the edit page. To do this, we
will use the ``url`` method on the view:
-.. include:: groktut/redirection/src/sample/app_templates/index.pt
+.. include:: groktut/redirection/src/pebbles/app_templates/index.pt
:literal:
Giving ``url`` a single string argument will generate a URL to the
@@ -979,7 +999,7 @@
Now let's change the edit form so that it redirects back to the
``index`` page after you press the submit button:
-.. include:: groktut/redirection/src/sample/app.py
+.. include:: groktut/redirection/src/pebbles/app.py
:literal:
The last line is the new one. We use the ``url`` method on the view to
@@ -988,20 +1008,6 @@
special method available on all ``grok.View`` subclasses,
``redirect``. We tell the system to redirect to the ``index`` page.
-Showing the value in the form
------------------------------
-
-Let's change our application so it displays what we stored the edit
-form as well, not just on the index page.
-
-To make this work, change edit.pt so it reads like this:
-
-.. include:: groktut/showing_the_value_in_the_form/src/sample/app_templates/edit.pt
- :literal:
-
-The only change is that we have used ``tal:attributes`` to include the
-value of the ``text`` attribute of the context object in the form.
-
The rules of persistence
------------------------
@@ -1040,11 +1046,11 @@
instead, we do need to take special action. Let's change our example
code (based on the last section) to use a mutable object (a list):
-.. include:: groktut/the_rules_of_persistence/src/sample/app.py
+.. include:: groktut/the_rules_of_persistence/src/pebbles/app.py
:literal:
-We have now changed the ``Sample`` class to do something new: it has
-an ``__init__`` method. Whenever you create the ``Sample`` application
+We have now changed the ``Pebbles`` class to do something new: it has
+an ``__init__`` method. Whenever you create the ``Pebbles`` application
object now, it will be created with an attribute called ``list``,
which will contain an empty Python list.
@@ -1053,9 +1059,9 @@
didn't do that, our container would not be fully initialized.
You will also notice a small change to the ``update`` method of the
-``Edit`` class. Instead of just storing the text as an attribute of
-our ``Sample`` model, we add each text we enter to the new
-``list`` attribute on.
+``Edit`` class. Instead of just storing the quantity as an attribute of
+our ``Pebbles`` model, we append each entered number to the
+``gifts`` attribute.
Note that this code has a subtle bug in it, which is why we've added
the comment. We will see what bug this is in a little bit. First,
@@ -1063,18 +1069,18 @@
We change ``index.pt`` so that it displays the list:
-.. include:: groktut/the_rules_of_persistence/src/sample/app_templates/index.pt
+.. include:: groktut/the_rules_of_persistence/src/pebbles/app_templates/index.pt
:literal:
We've also changed the text of the link to the ``edit`` page to reflect
the new adding behavior of our application.
We need to undo the change to the ``edit.pt`` template that we
-made in the last section, as each time we edit a text we now *add* a
-new text, instead of changing the original. There is therefore no text
+made in the last section, as each time we edit a number we now *add* a
+new quantity, instead of changing the original. There is therefore no value
to show in as the input value anymore:
-.. include:: groktut/the_rules_of_persistence/src/sample/app_templates/edit.pt
+.. include:: groktut/the_rules_of_persistence/src/pebbles/app_templates/edit.pt
:literal:
.. sidebar:: evolution
@@ -1092,17 +1098,16 @@
Look at the output Zope gave when we tried to load our page::
- AttributeError: 'Sample' object has no attribute 'list'
+ AttributeError: 'Pebbles' object has no attribute 'gifts'
-But we just changed our object to have an attribute ``list``, right?
-Yes we did, but only for *new* instances of the Sample object. What we
-are looking at is the sample object from before, still stored in the
+But we just changed our object to have an attribute ``gifts``, right?
+Yes we did, but only for *new* instances of the ``Pebbles`` object. What we
+are looking at is the old ``Pebbles`` object, still stored in the
object database. It has no such attribute. This isn't a bug by the way
(for our actual bug, see later in this section): it is just a database
problem.
-What to do now? The simplest action to take during development is to
-simply remove our previously installed application, and create a new
+What to do now? Restarting is not enough, because the old ``Pebbles`` instance is stored in the database. The simplest action to take during development is to simply remove our previously installed application, and create a new
one that *does* have this attribute. Go to the Grok admin screen:
http://localhost:8080
@@ -1112,15 +1117,15 @@
http://localhost:8080/test/edit
-Click on ``add a text`` and add another text. You will see the new
-texts appear on the ``index`` page.
+Click on ``Add a number`` and add another quantity. You will see the new
+quantity appear on the ``index`` page.
Everything is just fine now, right? In fact, not so! Now we will get
to our bug. Restart Zope and look at the index page again:
http://localhost:8080/test
-None of the texts we added were saved! What happened? We broke the
+None of the quantities we added were saved! What happened? We broke the
third rule of persistence as described above: we modified a mutable
attribute and did not notify the database that we made this
change. This means that the object database was not aware of our
@@ -1152,7 +1157,7 @@
We can easily amend this by adding one line to the code:
-.. include:: groktut/the_rules_of_persistence2/src/sample/app.py
+.. include:: groktut/the_rules_of_persistence2/src/pebbles/app.py
:literal:
We've now told Zope that the context object has changed (because we
@@ -1165,30 +1170,129 @@
database.
The code shown so far is a bit ugly in the sense that typically we
-would want to manage our state in the model code (the ``Sample``
+would want to manage our state in the model code (the ``Pebbles``
object in this case), and not in the view. Let's make one final
change to show what that would look like:
-.. include:: groktut/the_rules_of_persistence3/src/sample/app.py
+.. include:: groktut/the_rules_of_persistence3/src/pebbles/app.py
:literal:
-As you can see, we have created a method ``addText`` to the model that
-takes care of amending the list and informing the ZODB about it. This
-way, any view code can safely use the API of ``Sample`` without having
+As you can see, we have created a method ``addGifts`` to the model that
+takes care of appending to the list and informing the ZODB about it. This
+way, any view code can safely use the API of ``Pebbles`` without having
to worry about the rules of persistence itself, as that is the model's
responsibility.
+.. sidebar:: persistent lists and dicts
+
+ Since lists and dictionaries are so common in Python code, Zope 3
+ provides persistent flavors of them as well. In the ``Pebbles`` example,
+ the ``gifts`` attribute could be created as an instance of
+ ``PersistentList``, a class defined in the ``persistent.list``` module.
+ The module ``persistent.dict` contains a ``PersitentDict`` class.
+ If you use one these classes, there is no need to worry about setting
+ the ``_p_changed`` flag. However, since these classes are not memory
+ efficient, look for information on the Zope ``BTrees`` package
+ if you need to store large quantities of items.
+
+
+
+
+
+Containers
+----------
+
+A container is a special kind of model object that can contain other
+objects. Our ``Pebbles`` application is already a container, as it
+subclasses ``grok.Container``. What we will do in this section is
+build an application that actually puts something into that container.
+
+Grok applications ar typically composed of containers and
+models. Containers are objects that can contain models. This includes
+other containers, as a container is just a special kind of model.
+
+From the perspective of Python, you can think of containers as
+dictionaries. They allow item access (``container['key']``) to get at
+its contents. They also define methods such as ``keys()`` and
+``values()``. Containers do a lot more than Python dictionaries
+though: they are persistent, and when you modify them, you don't have
+to use `_p_changed` anywhere to notice you changed them. They also
+send out special events that you can listen to when items are placed
+in them or removed from them. For more on that, see the section on
+events (XXX).
+
+Our application object will have a single index page that displays the
+list of items in the container. You can click an item in the list to
+view that item. Below the list, it will display a form that allows you
+to create new items.
+
+Here is the ``app.py`` of our new application:
+
+.. include:: groktut/containers/src/sample/app.py
+ :literal:
+
+As you can see, ``Sample`` is unchanged. We have also created our
+first non-application object, ``Entry``. It is just a
+``grok.Model``. It needs to be created with an argument ``text`` and
+this text is stored in it. We intend to place instances of ``Entry``
+in our ``Sample`` container.
+
+Next are the views. We have an ``index`` page for the ``Sample``
+container. When its ``update()`` is triggered with two values,
+``name`` and ``text``, it will create a new ``Entry`` instance with
+the given text, and place it under the container under the name
+``name``. We use the dictionary-like interface of our ``Sample``
+container to put our new ``Entry`` in the container.
+
+Here is the associated template for ``SampleIndex``, ``sampleindex.pt``:
+
+.. include:: groktut/containers/src/sample/app_templates/sampleindex.pt
+ :literal:
+
+The first section in the template (``<h2>Existing entries</h2>``)
+displays a list of the items in the container. We again use
+dictionary-like access using ``keys()`` to get a list of all the names
+of the items in the container. We create a link to these items using
+``view.url()``.
+
+The next section (``<h2>Add a new entry</h2>``) displays a simple form
+that submits to the index page itself. It has two fields, ``name`` and
+``text``, which we already have seen handled by ``update()``.
+
+Finally, we have an ``index`` page for ``Entry``. It just has a template
+to display the ``text`` attribute:
+
+.. include:: groktut/containers/src/sample/app_templates/entryindex.pt
+ :literal:
+
+Restart Zope and try this application. Call your application
+``test``. Pay special attention to the URLs.
+
+First, we have the index page of our application:
+
+ http://localhost:8080/test
+
+When we create an entry called ``hello`` in the form, and then click on it
+in the list, you see an URL that looks like this:
+
+ http://localhost:8080/test/hello
+
+We are now looking at the index page of the instance of ``Entry``
+called ``hello``.
+
+What kind of extensions to this application can we think of? We could
+create an ``edit`` form that allows you to edit the text of
+entries. We could modify our application so that you can not just add
+instances of ``Entry``, but also other containers. If you made those
+modifications, you would be on your way to building your own content
+management system with Grok.
+
+
+????????????????????????????????
+
Explicitly associating a view with a model
------------------------------------------
-How does Grok know that a view belongs to a model? In the previous
-examples, Grok has made this association automatically. Grok could do
-this because there was only a single model defined in the module
-(``Sample``). In this case, Grok is clever enough to automatically
-associate all views defined elsewhere in the same module to the only
-model. Behind the scenes Grok made the model the *context* of the
-views.
-
Everything that Grok does implicitly you can also tell Grok to do
explicitly. This will come in handy later, as you may sometimes need
(or want) to tell Grok what to do, overriding its default behavior. To
@@ -1287,90 +1391,3 @@
to structure your application so you can use Grok's default
conventions.
-Containers
-----------
-
-A container is a special kind of model object that can contain other
-objects. Our ``Sample`` application is already a container, as it
-subclasses ``grok.Container``. What we will do in this section is
-build an application that actually puts something into that container.
-
-Grok applications ar typically composed of containers and
-models. Containers are objects that can contain models. This includes
-other containers, as a container is just a special kind of model.
-
-From the perspective of Python, you can think of containers as
-dictionaries. They allow item access (``container['key']``) to get at
-its contents. They also define methods such as ``keys()`` and
-``values()``. Containers do a lot more than Python dictionaries
-though: they are persistent, and when you modify them, you don't have
-to use `_p_changed` anywhere to notice you changed them. They also
-send out special events that you can listen to when items are placed
-in them or removed from them. For more on that, see the section on
-events (XXX).
-
-Our application object will have a single index page that displays the
-list of items in the container. You can click an item in the list to
-view that item. Below the list, it will display a form that allows you
-to create new items.
-
-Here is the ``app.py`` of our new application:
-
-.. include:: groktut/containers/src/sample/app.py
- :literal:
-
-As you can see, ``Sample`` is unchanged. We have also created our
-first non-application object, ``Entry``. It is just a
-``grok.Model``. It needs to be created with an argument ``text`` and
-this text is stored in it. We intend to place instances of ``Entry``
-in our ``Sample`` container.
-
-Next are the views. We have an ``index`` page for the ``Sample``
-container. When its ``update()`` is triggered with two values,
-``name`` and ``text``, it will create a new ``Entry`` instance with
-the given text, and place it under the container under the name
-``name``. We use the dictionary-like interface of our ``Sample``
-container to put our new ``Entry`` in the container.
-
-Here is the associated template for ``SampleIndex``, ``sampleindex.pt``:
-
-.. include:: groktut/containers/src/sample/app_templates/sampleindex.pt
- :literal:
-
-The first section in the template (``<h2>Existing entries</h2>``)
-displays a list of the items in the container. We again use
-dictionary-like access using ``keys()`` to get a list of all the names
-of the items in the container. We create a link to these items using
-``view.url()``.
-
-The next section (``<h2>Add a new entry</h2>``) displays a simple form
-that submits to the index page itself. It has two fields, ``name`` and
-``text``, which we already have seen handled by ``update()``.
-
-Finally, we have an ``index`` page for ``Entry``. It just has a template
-to display the ``text`` attribute:
-
-.. include:: groktut/containers/src/sample/app_templates/entryindex.pt
- :literal:
-
-Restart Zope and try this application. Call your application
-``test``. Pay special attention to the URLs.
-
-First, we have the index page of our application:
-
- http://localhost:8080/test
-
-When we create an entry called ``hello`` in the form, and then click on it
-in the list, you see an URL that looks like this:
-
- http://localhost:8080/test/hello
-
-We are now looking at the index page of the instance of ``Entry``
-called ``hello``.
-
-What kind of extensions to this application can we think of? We could
-create an ``edit`` form that allows you to edit the text of
-entries. We could modify our application so that you can not just add
-instances of ``Entry``, but also other containers. If you made those
-modifications, you would be on your way to building your own content
-management system with Grok.
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