Plone 3 Products Development Cookbook

Plone 3 Products Development Cookbook

Overview of this book

The Plone Content Management System is one of the best open source CMS, because by using Plone's development framework you can extend its functionality according to the specific requirements of your website. The Plone framework has lots of components that can be used to create add-ons or extensions called Plone Products. You can optimize your site for improved usability, accessibility, and security by creating custom Plone products.This book covers recipes that will help you create custom Plone Products and implement them on your website. Every topic covered in this book is accompanied by essential fundamentals and step-by-step explanation that will help you understand it better. With the help of this book you will be able to create custom Plone products that are well suited for your website.You can read the whole book or just pick recipes relevant for you; cross references help you understand the recipes even if you do not read them in order.If you work through the book in order, you will start by setting up an example project of a news website that will be developed throughout the book. You will learn about all of the necessary tools a Plone developer must have before starting any project. You will develop the website further by detecting problems and debugging them. You will be able to modify code on-the-fly or get help on how to do some tasks by installing and using special tools such as IPython, ipdb, and PDBDebugMode. You will then create a new content type, based on an existing one, and wrap the final product into a Python egg.You will set up automated testing to prevent errors in code that have evolved in the development stage. You will use paster to automatically create a new custom content type from scratch. You will improve the performance of your application by creating lightweight content types and following other recipes covered in this book. Key features such as usability, internationalization, accessibility and security are covered to make sure that your development and customizations will be at the level of Plone core and its most remarkable add-on products.You will improve your user interface by creating simple client-side visual changes and server-side manipulation of objects. You will learn to create and manage portlets by using Portlet manager and customize your website by modifying third-party products. Finally you will learn to communicate with an external non-Python-based system and make your products available for future use.

Plone 3 Products Development Cookbook

Credits

About the Authors

About the Reviewers

Preface

Free Chapter

Getting Started

Introduction

Installing Python on Linux

Installing Plone on Linux

Installing Plone on Windows

Checking out code from a version controlsystem

Creating a Plone site

Using Development Tools

Introduction

Accessing an IPython powered shell

Taking advantage of an enhanced interactive Python debugger with ipdb

Discovering Zope/Plone APIs and docstrings with DocFinderTab

Opening an online Python shell on Plone using Clouseau

Debugging Zope exceptions with PDBDebug Mode

Applying code changes on-the-fly using plone.reload

Creating Content Types with ArchGenXML

Introduction

Installing ArchGenXML

Configuring ArgoUML

Creating a model

Generating code

Customizing generated code

Installing the product

Automatically installing products in your Zope instance

Prevent Bugs through Testing

Introduction

Working with paster-generated test suites

Creating a test suite with ArchGenXML

Creating doctests with iPython

Zope functional testing

Using Selenium functional tests

Creating a Custom Content Type with Paster

Introduction

Creating an Archetypes product with paster

Adding a content type into a product

Changing the base class in paster content types

Adding fields to a content type

Adding a custom validator to a content type

Modifying the view of a content type with jQuery

Creating Lightweight Content Types

Introduction

Creating a product package structure

Creating a folderish content type

Creating the user interface for Zope 3 content types

Creating content types with Dexterity

Improving Product Performance

Introduction

Installing CacheFu with a policy product

Improving performance by tweaking expensive code

Testing server load and benchmarking our code

Internationalization

Introduction

Adding i18ndude support to ArchGenXML

Installing i18ndude standalone

Using i18ndude

Using Placeless Translation Services for i18n support

Using zope.i18n approach

Overriding others' translations

Using i18n with ArchGenXML

Using i18n with paster-created products

Adding i18n support to any product

Translating content

Setting language options

Adding Security to your Products

Introduction

Creating a new permission

Adding a new role

Adding user groups

Testing security customizations

Protecting operations with permissions

Managing security with workflows

Adding configuration options in Plone control panel

Improving User Interface with KSS

Introduction

Preparing a form to take full advantage of KSS

Changing end user pages with client-side KSS

Submitting data via AJAX

Creating Portlets

Introduction

Creating a portlet package

Customizing a new portlet according to our requirements

Testing portlets

Assigning portlets automatically

Extending Third-Party Products

Introduction

Using skin layers

Overriding Zope 3 components

Customizing Zope 3 browser templates and files

Subscribing to others' events

Using the ZCA to extend a third-party product: Collage

Interacting with other Systems: XML-RPC

Introduction

Creating a configuration form

Registering a local utility

Registering a global utility

Getting our Products ready for Production

Introduction

Installing and configuring an egg repository

Submitting products to an egg repository

Writing a production buildout

Creating a Policy Product

Creating a policy product

Index

Customer Reviews

5 star

4 star

3 star

2 star

1 star

Installing Plone on Linux

Now that we have a valid Python version, we can install Plone.

Note

There is an alternate and very handy method to install Plone on Linux (and Mac and Windows) called Unified Installer. It is a bundle that installs not only Zope and Plone, but also Python and other necessary packages. If you want to try it, go to http://plone.org/download and download the version of your choice.

Getting ready

ZopeSkel is a Python package that provides development templates for Zope and Plone. It will help us at several different stages of our projects. We will use it here to create a buildout environment. First, we must be sure we have it properly installed:

Activate your just installed Python 2.4 (or whatever version you have installed) virtualenv:
```
$ source ~/libexec/python2.4/bin/activate
```
Install ZopeSkel:
```
(python2.4)$ easy_install-2.4 ZopeSkel
```
If you already have it, check for the latest version by running:
```
(python2.4)$ easy_install-2.4 -U ZopeSkel
```

How to do it…

Create a buildout with paster: Once you have the correct ZopeSkel version installed for your Python environment, run the following command to create a Zope/Plone buildout:
```
(python2.4)$ paster create -t plone3_buildout
```
Note
Starting with ZopeSkel 2.15, when creating buildout environments with paster, you will see a warning message informing you that Unified Installer is the best option for installations and paster is just for experts. Although Unified Installer is great and incredibly useful, we think Plone developers should know how to create a Plone environment from scratch and this is the way to do it.

Run the bootstrap process:

(python2.4) $ cd pox
(python2.4) $ python bootstrap.py

Edit the buildout.cfg file and locate the eggs parameter in the main [buildout] section and add PIL (Python Imaging Library) as a package to be downloaded and installed during buildout.
```
[buildout]
...
eggs = 
    PIL
....
```
Buildout your Zope instance: This last step is to run the buildout process.
```
(python2.4) $ ./bin/buildout
```

How it works…

Executing Step 1 will start a wizard to help with the creation of the buildout.cfg, we need. For each of the following options, provide these values:

Option	Value
Enter project name	pox, after Plone and OpenX, the fictitious project we are tackling in this book. Here you can choose whatever name you want and `paster` will create a directory with that name.
Expert Mode?	With the `plone3_buildout` template, no matter which mode you choose (`easy/expert/all`), you’ll be prompted for the following options.
Plone Version	A valid released version of Plone. Although we have run `paster` with the `plone3_buildout` template, we can enter Plone 4 version numbers. Don’t forget to choose 3.x versions for Python 2.4 and 4.x versions for Python 2.6.
Zope2 Install Path	If you want to share this instance Zope installation with another existing one, enter its path. If not, just leave it blank.
Plone Products Directory	Again, if you already have a previous installation with the list of Plone products you want to use, enter its path. If you want a fresh installation, leave it blank.
Initial Zope Username	The desired Zope administrator user.
Initial User Password	Choose one. Don’t leave it blank, as you won’t be able to log in.
HTTP Port	Pick a free port in your development machine.
Debug Mode	off
Verbose Security	off

A new folder named pox (the project name we used in the first option) with a basic directory structure and two very important files—bootstrap.py and buildout.cfg— will have been created.

In Step 2, we run the bootstrap process to complete the directory structure and generate the executable buildout file.

Let’s see what buildout.cfg looks like after Step 3, where we added PIL in the eggs parameter:

[buildout]
parts =
    zope2
    productdistros
    instance
    zopepy

This is a four-part buildout. Each part will be run consecutively.

extends = http://dist.plone.org/release/3.3.4/versions.cfg
versions = versions

Egg version numbers will be fixed (or pinned) to the ones listed in the URL above. Note that the URL is set according to the release number you have chosen when you ran the paster command before.

find-links =
    http://dist.plone.org/release/3.3.4
    http://dist.plone.org/thirdparty

Downloaded and installed eggs should be fetched from these package index servers.

# Add additional eggs here
eggs =
    PIL

# Reference any eggs you are developing here, one per line
# e.g.: develop = src/my.package
develop =

We will start using the eggs and develop parameters in the next chapter as we begin adding packages to our Zope instance. Meanwhile, we will need Python Imaging Library (PIL).

[zope2]
# For more information on this step and configuration options: 
# http://pypi.python.org/pypi/plone.recipe.zope2install
recipe = plone.recipe.zope2install
fake-zope-eggs = true
url = ${versions:zope2-url}

A recipe for Zope 2 installation:

[productdistros]
recipe = plone.recipe.distros
urls =
nested-packages =
version-suffix-packages =

A special recipe to download and install old-style Zope products (not released as eggs):

[instance]
recipe = plone.recipe.zope2instance
zope2-location = ${zope2:location}
user = admin:admin
http-address = 8080
#debug-mode = on
#verbose-security = on
eggs =
    Plone
    ${buildout:eggs}

# If you want to register ZCML slugs for any packages, 
# list them here.
# e.g. zcml = my.package my.other.package
zcml =

products =
    ${buildout:directory}/products
    ${productdistros:location}

These are several configuration settings for the Zope instance that will be created during the buildout process.

[zopepy]
recipe = zc.recipe.egg
eggs = ${instance:eggs}
interpreter = zopepy
extra-paths = ${zope2:location}/lib/python
scripts = zopepy

zopepy is a Python interpreter with a sys.path variable full of the downloaded eggs and packages available at the instance's /lib/python folder. This is particularly useful to check if every package is available as expected.

The last step will take longer to execute than the previous steps, as it will download all the eggs listed in the buildout.cfg file above and all their dependencies (at the time of writing, Plone 3.3.4 has 74 direct dependencies).

This buildout executes the four parts explicitly mentioned in the parts definition at the top of the file:

[zope2]: Its plone.recipe.zope2install recipe downloads and installs the Zope 2 version mentioned in ${versions:zope2-url}. You can find this parameter at http://dist.plone.org/release/3.3.4/versions.cfg, the URL of the extends parameter.
[productdistros]: It executes with its plone.recipe.distros recipe. In our example, we don’t have any urls listed, so it won’t process anything here.
Note
Note that there are very few old-style Zope products that are really worth installing in a modern instance. Being old-style means being unmaintained, so use them carefully.
[instance]: It uses a plone.recipe.zope2instance recipe to install a Zope instance. We can see here most of the options we set when we ran the paster command before.
[zopepy]: Using zc.recipe.egg will create a Python interpreter named zopepy with all the eggs found in the instance section (check ${instance:eggs}) in the sys.path variable.

Plone 3 Products Development Cookbook

Plone 3 Products Development Cookbook

Overview of this book

Related Content you might be interested in

Current Title:

Plone 3 Products Development Cookbook

Installing Plone on Linux

Note

Getting ready

How to do it…

Note

How it works…

Note

See also