Doc 6 Zope 3 - Basics

Contents

Reading Assignment    

Zope Introduction    

What is Zope?    

Installing Zope    

Using Zope Interface    

Programing Zope    

First Example & Motivation    

Zope Schemas & Interfaces    

Interfaces    

Existing Schema    

Schema Attributes    

Persistence    

Installing Book in a ZopeInstance    

 

Copyright ©, All rights reserved. 2005 SDSU & Roger Whitney, 5500 Campanile Drive, San Diego, CA 92182-7700 USA. OpenContent ( http://www.opencontent.org/opl.shtml ) license defines the copyright on this document.

 

References

 

Web Component Development with Zope 3, Philipp von Weitershausen, Springer-Verlag, 2005

This document covers through Section 7.1 in the above text

 

The Zope 3 Developers Book - An Introduction for Python Programmers, Stephan Richter, http:// www.zope.org/Wikis/DevSite/Projects/ComponentArchitecture/FrontPage/Zope3Book

 

The Zope Book 2.6, http://www.zope.org/Documentation/Books/ZopeBook/

 

 

Reading Assignment

 

The chapter numbers above refer to chapters in the book Web Component Development with Zope 3, von Weitershausen, Springer-Verlag, 2005

 

 

Zope Introduction

What is Zope?

 

Z Object Publishing Environment

Zope is a system for Web applications that

1. Written in Python

2. Supports/Automates much of the web application steps

3. Persistence

4. View creation

5. Data validation

 

 

Why Zope 3

 

Zope 3 cleans up some issues with Zope 2

 

Installing Zope

 

Instructions in Chapter 2 of von Weitershausen's book work for

6. Unix

7. Windows

 

Short Version of Instructions

Go to http://www.zope.org/Products/Zope3/3.0.1

Download correct version (exe for windows)

Follow the instructions in the README in the download

 

 

Creating a Zope Instance

Go to the directory that you want to contain your Zope files

Run (unix)

/usr/local/ZopeX3-3.0.1/bin/mkzopeinstance -d Zope3Instance -u aUsername:aPassword

 

or (windows)

C:\Python23\python\Scripts\mkzopeinstance -d Zope3Instance -u aUsername:aPassword

 

Note "Zope 3 In stance" will be a directory, so you can use another string

aUsername and aPassword are for manager of the zope instance

 

Multiple instance of Zope can run at the same time

Each instance uses a different port

 

 

Starting Zope

Unix

cd Zope3Instance

bin/runzope

Windows

cd Zope3Instance

C:\Python23\python bin\runzope

 

Zope uses the port 8080 by default

 

Edit Zope3Instance/etc/zope.conf to change defaults

 

 

 

Using Zope Interface

 

Demo

Useful reading

The new Web-based User Interface , Richter, ( PDF )

The Zope Book 2.6 ( PDF )

chapter Using The Zope Management Interface

 

 

Programing Zope

First Example & Motivation

Web Site for a Bookstore

 

For simplicity a book has

8. Title

9. Author

10. Publication Date

 

class Book:

    title = ''

    author = ''

    date = None

 

Issue - Data Validation

How to prevent?

badData = Book()

badData.title = [1,2, 'dog', 3.234]

badData.date = 'cat'

 

 

 

Zope Schemas & Interfaces

 

Schemas - used to indicate type information

Interface - used to specify schemas

 

import sys

sys.path.append('/usr/local/ZopeX3-3.0.1/lib/python/')

 

zope.interface import Interface

from zope.schema import TextLine, Date

 

class IBook(Interface):

    title = TextLine(

        title = u'Title',

        description = u'Title of the book',

        required = True)

    

    author = TextLine(

        title = u'author',

        description = u'Author of the book',

        required = True)

    

    date = Date(

        title = u'Date',

        description = u'Date book was published',

        required = True)

 

 

Using the Schema

import sys

sys.path.append('/usr/local/ZopeX3-3.0.1/lib/python/')

 

from zope.interface import implements

from zope.schema.fieldproperty import FieldProperty

 

class Book(object):

    implements(IBook)

    

    title = FieldProperty(IBook['title'])

    author =  FieldProperty(IBook['author'])

    date = FieldProperty(IBook['date'])

 

Sample Program - Major Python Magic

noBadData = Book()

noBadData.author = ['cat', 1]                #Runtime error

 

The schema is trapping a direct assignment to an attribute to check type usage

 

Some Details of the Example

 

Zope path in PYTHONPATH

import sys

sys.path.append('/usr/local/ZopeX3-3.0.1/lib/python/')

 

 

When run in Zope this is not needed

Uses sys.path.append rather than PYTHONPATH to make sure path dependancy is explicitly shown

Path shown is for Unix install of Zope

 

 

Interfaces

zope.interface import Interface

 

class IBook(Interface):

 

from zope.interface import implements

 

class Book(object):

    implements(IBook)

 

Interfaces are defined by a library not part of language

Compiler does not know about interfaces

 

Interfaces are subclasses of Interface

By convention Interface names start with "I"

A class must subclass object when implementing an interface

object is used to make schema type checking work

 

implements does not force the class to have all methods

class Book(object):

    implements(IBook)

    pass

 

 

Existing Schema

Abstract

Basic Types

Special Types

 

 

Schema Attributes

Attributes for all Fields

 

 

Specialized Attributes

 

 

More Details

 

 

Persistence

 

Modifying the book so book objects are stored in a database

from persistent import Persistent

from zope.interface import implements

from zope.schema.fieldproperty import FieldProperty

from bookstore.interfaces import IBook

 

class Book(Persistent):

    implements(IBook)

    

    title = FieldProperty(IBook['title'])

    author =  FieldProperty(IBook['author'])

    date = FieldProperty(IBook['date'])

 

Zope will now store the book in ZODB

Zope Object Database

 

 

 

Installing Book in a ZopeInstance

 

We would like to add and modify books in Zope

 

Tell Zope about the bookstore Package

 

In the directory "Zope3Instance/etc/package-includes/"

Add the file "book-configure.zcml"

book-configure.zcml

<include package="bookstore"/>

 

bookstore Package

 

In "Zope3Instance/lib/python" create the directory bookstore

Files to add to "Zope3Instance/lib/python / bookstore"

11. __in it__.py

12. book.py

13. interfaces.py

14. configure.zcml

 

 

 

Files in Zope3Instance/lib/python/bookstore

 

__in it__.py

# make this directory a package

 

book.py

from persistent import Persistent

from zope.interface import implements

from zope.schema.fieldproperty import FieldProperty

from bookstore.interfaces import IBook

 

class Book(Persistent):

    implements(IBook)

    

    title = FieldProperty(IBook['title'])

    author =  FieldProperty(IBook['author'])

    date = FieldProperty(IBook['date'])

 

 

 

interfaces.py

from zope.interface import Interface

from zope.schema import TextLine, Date

 

class IBook(Interface):

    title = TextLine(

        title = u'Title',

        description = u'Title of the book',

        required = True)

    

    author = TextLine(

        title = u'author',

        description = u'Author of the book',

        required = True)

    

    date = Date(

        title = u'Date',

        description = u'Date book was published',

        required = True)

 

 

 

configure.zcml

<configure xmlns=" http://namespaces.zope.org/zope ">

 

<interface

    interface=".interfaces.IBook"

    type="zope.app.content.interfaces.IContentType"

/>

 

<content class=".book.Book">

    <factory

        id="bookstore.book.Book"

        title="Create a new book"

        description="This factory instantiates new books"

    />

    <require

        permission="zope.View"

        interface=".interfaces.IBook"

    />

    <require

        permission="zope.ManageContent"

        set_schema=".interfaces.IBook"

    />

 

</content>

 

<include package=".browser" />

 

</configure>

 

 

 

Python Package names

 

<content class=".book.Book">

 

In ".book.Book" the leading peroid means:

Current package (which is bookstore)

 

So we could write this as:

 

<content class="bookstore.book.Book">

 

Browser files

These files tell Zope

15. To list books as objects that can be created

16. How to generate a page to edit a book

 

 

In "Zope3Instance/lib/python/bookstore" create the directory browser

 

In "Zope3Instance/lib/python/bookstore/browser" add files:

17. __init__.py

18. configure.zcml

 

We will be adding more later

 

 

__in it__.py

# make this directory a package

 

 

 

configure.zcml

<configure

    xmlns=" http://namespaces.zope.org/zope "

    xmlns:browser=" http://namespaces.zope.org/browser "

    >

 

  <browser:addMenuItem

      title="Book"

      class="bookstore.book.Book"

      permission="zope.ManageContent"

      view="AddBook.html"

      />

 

  <browser:addform

      schema="bookstore.interfaces.IBook"

      content_factory="bookstore.book.Book"

      label="Add a Book"

      name="AddBook.html"

      permission="zope.ManageContent"

      />

 

  <browser:editform

      schema="bookstore.interfaces.IBook"

      label="Edit"

      name="edit.html"

      menu="zmi_views" title="Edit"

      permission="zope.ManageContent"

      />

</configure>

 

 

Zope Page

 

Note the add box now contains "Book"

 

 

 

Auto-generated Form for adding a book