1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
|
+++++++++++++
Blog Tutorial
+++++++++++++
:author: Ian Bicking <ianb@colorstudy.com>
:revision: $Rev: 2321 $
:date: $LastChangedDate: 2005-04-09 17:55:39 -0500 (Sat, 09 Apr 2005) $
.. contents::
.. note::
This tutorial is not yet finished. What you see is what you get,
and yeah that's not a whole lot.
Introduction
============
This tutorial will go through the process of creating a blog using
`Python Paste <http://pythonpaste.org>`_, SQLObject_, and `Zope Page
Templates`_. This blog will rely heavily on static publishing -- that
is, when at all possible flat HTML pages will be written to disk. For
some parts (e.g., posting a new item) this will of course be
infeasible, but for most of the site this should work fine.
.. _SQLObject: http://sqlobject.org
.. _Zope Page Templates: http://www.zope.org/DevHome/Wikis/DevSite/Projects/ZPT/FrontPage
As much as possible, this code will be accompanied by unit tests, and
test-driven methodologies. Doing test-driven documenting of the
incremental process of creating test-driven software may get a little
hairy, but wish me luck!
This tutorial presupposes you are somewhat comfortable with the basic
stack -- the `To-Do Tutorial`_ is a better place to start for a
beginner.
.. _To-Do Tutorial: TodoTutorial.html
Setting Up The App
==================
.. note::
We're doing all this in the Python interpreter, even though you'd normally do
some of this in the shell. This way the authors of this tutorial
can use something called doctest_, which allows this tutorial to
be tested Python in an automated way.
.. _doctest: http://python.org/doc/current/lib/module-doctest.html
.. comment:
>>> from paste.tests.doctest_webapp import *
>>> BASE = '/var/www/example-builds/wkblog'
>>> import sys
>>> clear_dir(BASE)
>>> run("app-setup create --template=webkit_zpt %s" % BASE)
>>> os.chdir(BASE)
::
$ export PYTHONPATH=/path/to/Paste:$PYTHONPATH
$ BASE=/var/www/example-builds/wkblog
$ app-setup create --template=webkit_zpt $BASE
$ cd $BASE
The Model
=========
Since we're using SQLObject, we'll be doing the complete model in
that. The predecessor of this blog used flat files, custom-written
indexes, and simple rfc822_ based files for structure. It did not
scale well at all.
.. _rfc822: http://python.org/doc/current/lib/module-rfc822.html
Here's the model:
.. run:
create_file('db.py', 'v1', r"""
from sqlobject import *
try:
from datetime import datetime
now = datetime.now
except ImportError:
from mx import DateTime
now = DateTime.now
class Article(SQLObject):
url = StringCol(notNull=True)
title = StringCol()
content = StringCol(notNull=True)
content_mime_type = StringCol(notNull=True)
author = ForeignKey('User')
parent = ForeignKey('Article', default=None)
created = DateTimeCol(notNull=True, default=now)
last_updated = DateTimeCol(default=None)
atom_id = StringCol()
hidden = BoolCol(notNull=True, default=False)
article_type = StringCol(notNull=True, default='article')
categories = RelatedJoin('Category')
class Category(SQLObject):
name = StringCol(alternateID=True)
articles = RelatedJoin('Article')
class User(SQLObject):
class sqlmeta:
table = 'user_info'
username = StringCol(alternateID=True)
email = StringCol()
name = StringCol()
password_encoded = StringCol()
role = StringCol(notNull=True, default='user')
""")
.. raw:: html
:file: resources/BlogTutorial/db.py.v1.gen.html
A few things to note:
* Sadly, both datetime_ and mxDateTime_ are pseudo-standards. Well,
datetime is the standard, but mxDateTime has the legacy. So we have
to do this little dance to import one or the other. (We use ``now``
later as a default)
.. _datetime: http://python.org/doc/current/lib/module-datetime.html
.. _mxDateTime: http://www.egenix.com/files/python/mxDateTime.html
* All the columns allow ``NULL`` by default, unless we say
``notNull=True``.
* ``ForeignKey('User')`` is a join to another table (the ``User``
table, of course). We have to use strings to refer to other class,
because in this case the ``User`` class hasn't even been created.
Generally all references between classes are by name.
* ``created`` has a default. You can give a fixed default (like
``True`` or ``3``), or you can pass in a function that is called.
In this case, if you don't indicate ``Article(...,
created=something)`` then ``created`` will be the current date and
time. Unless a default is explicitly given, it is an error to leave
a column out of the constructor. ``NULL`` (which is ``None`` in
Python) is *not* considered a default.
* Some column types don't relate directly to database types. For
instance, though PostgreSQL has a ``BOOLEAN`` type, most databases
don't, so ``BoolCol`` translates to some kind of ``INT`` column on
those database.
* ``RelatedJoin('Category')`` creates a mapping table
(``article_category``) and is a many-to-many join between articles
and categories.
* ``user`` isn't a valid table name in many databases, so while the
class is named ``User``, the table actually is ``user_info``. This
kind of extra information about a class is typically passed in
through the ``sqlmeta`` inner class.
These classes have lots of other *behavior*, but this should be a good
list of actual information. We'll add more behavior later.
Now we'll create the database. First we configure it, adding these
lines::
import os
database = 'sqlite:%s/data.db' % os.path.dirname(__file__)
You could also use::
database = 'mysql://user:passwd@localhost/dbname'
database = 'postgresql://user:password@localhost/dbname'
.. comment (change server.conf)
>>> change_file('server.conf', [('insert', 2, r"""import os
... database = 'sqlite:%s/data.db' % os.path.dirname(__file__)
...
... """)])
Now we'll use ``sqlobject-admin`` to set up the tables:
.. comment (do it)
>>> run('sqlobject-admin create -f server.conf -m wkblog.db')
|
