Building Content Typeswith Dexterity

David GlickPlone Conference 2009

Groundwire uses the power of technology to connect people, organizations, and communities working to build a sustainable society.

What is a content type?

A way of categorizingthe items in your site

Page Something Else

Schema

Workflow

Custom view templates

Miscellaneous settings

• Placeful restrictions• Comments• Searchability• Per-type portlet assignments• etc.

History Lesson

http://commons.wikimedia.org/wiki/File:1893_Nina_Pinta_Santa_Maria_replicas.jpg

Content Management Framework (CMF)• Underlying framework for registering

types, assigning workflow• CMFDefault contains sample types which

used to be used by Plone• Not schema-based

Archetypes

• Schema-based form generation• Basis of Plone's current default content

types (ATContentTypes)• Not going away anytime soon

Dexterity

Martin Aspeli

Goals

http://www.fickr.com/photos/paul-w-locke/1662634481/sizes/m/

Make filesystem content type development sane

Make through-the-web content type development sane

Make it possible to switch back and forth between the 2

Philosophy

http://www.fickr.com/photos/ulrichsson/3519217737/

Reuse over reinvention

Produc ts .Arc he type s

Small over big

felds

widgets

base classes

storage

metadataschema

referenceengine

plone .de x te rity

plone.app.dexterity

plone.schemaeditor

z3c.form

plone.behavior

plone.app.relations

plone.directives.*

plone.autoform

plone.supermodel

Natural interaction over excessive generality

diffculty

time

Real code over generated code

Zope 3 over Zope 2

Automated testing over wishful thinking

Let's build a content type!

Installing Dexterity

[buildout]extends = http://dist.plone.org/release/3.3.1/versions.cfg http://good-py.appspot.com/release/dexterity/1.0a2

…[instance]…eggs = … plone.app.dexterity

Installing Dexterity

Dexterity Types Control Panel

Adding a Type

Adding a Type

Adding a 'Plonista' instance

Adding a 'Plonista' instance

The default 'Plonista' view

A few issues

• Bad short name for URL (“plonista”)• Showing lots of metadata fields we don't

care about• We want it to say “Name” instead of “Title”• Doesn't store anything interesting yet :)

...so let's fix it!

Behaviors

ATFile

schema

CustomATFile

s ubc la s s ing

ATFile

schema

behav iors

DexterityFile

model

thumbnailimage

name fromtitle

ratingsgeolocatable

versioned

s c hemae x te ns ion

ATFile

schema

schemaschema

schema Decolayout

Editing the 'Plonista' Behaviors

Disable this to hide the metadata

Enable this to generate short name from title

Adding a Field

Adding a Field

This will replace the title feld that used to come from the Dublin Core behavior.

Adding a Field

Editing a fieldWe are changing the title of this feld to 'Name'.

Edit a revised 'Plonista'

Rapid Prototyping

• The schema object in memory is directly modified, so changes take effect immediately.

• The changes are also serialized to XML and stored in the ZODB (in a property of the FTI), so they are persistent when Zope restarts.

Modifying a Type

• You can add, remove, and rename fields through the web.

• But, values stored in existing instances will not be automatically removed or converted. So be careful.

Some more desired refinements

• Custom add permission• Show the 'bio' field in a separate fieldset.

…we can't do these through the web (at least not yet)

Filesystem roundtripping

Web File s y s tem

Zope 3 Schema

XML schema in FTI

ContentEditing

SchemaEditing

xmlxml

XML schemaon flesystem

py

Schema asPython interface

GenericSetupimport/export

Externaltools

Exporting a type

• GenericSetup export for now;better UI coming :)

Minimal Dexterity package structure

• example.ploneconf09» /example• /ploneconf09

• /__init__.py• /configure.zcml• /profiles

• /default• /metadata.xml• /types.xml• /types

• plonista.xml

» /setup.py

setup.py

setup(name='example.ploneconf09', ... install_requires=[ 'setuptools', 'plone.app.dexterity', # -*- Extra requirements: -*- ], entry_points=""" [z3c.autoinclude.plugin] target = plone """, )

Make sure we automatically get Dexterity

Make sure we don't need a ZCML slug(in Plone 3.3 and greater)

__init__.py

# Nothing to see here; move along. :)

configure.zcml

<configure xmlns="http://namespaces.zope.org/zope" xmlns:grok="http://namespaces.zope.org/grok" xmlns:genericsetup="http://namespaces.zope.org/genericsetup" i18n_domain="example.ploneconf09">

<includeDependencies package="."/> <genericsetup:registerProfile name="default" title="Plone conference Dexterity example" directory="profiles/default" description="Installs the Dexterity example for the Plone conference." provides="Products.GenericSetup.interfaces.EXTENSION" />

</configure>

Loads ZCML for all dependency packages listed in setup.py

types.xml

metadata.xml

<?xml version="1.0"?><object name="portal_types" meta_type="Plone Types Tool"> <object name="plonista" meta_type="Dexterity FTI"/></object>

<metadata> <version>1</version> <dependencies> <dependency>profile-plone.app.dexterity:default</dependency> </dependencies></metadata>

plonista.xml<?xml version="1.0"?><object name="plonista" meta_type="Dexterity FTI" xmlns:i18n="http://xml.zope.org/namespaces/i18n"> <property name="title">Plonista</property> <property name="description">A member of the Plone community.</property> <property name="content_icon">document_icon.png</property> <property name="icon_expr">string:${portal_url}/document_icon.png</property> <property name="factory">plonista</property> <property name="link_target"></property> <property name="immediate_view">view</property> <property name="global_allow">True</property> <property name="filter_content_types">True</property> <property name="allowed_content_types"/> <property name="allow_discussion">False</property> <property name="default_view">view</property> <property name="view_methods"> <element value="view"/> </property> <property name="default_view_fallback">False</property>

plonista.xml (continued) <property name="add_permission">cmf.AddPortalContent</property> <property name="klass">plone.dexterity.content.Item</property> <property name="behaviors"> <element value="plone.app.content.interfaces.INameFromTitle"/> </property> <property name="schema"></property> <property name="model_source">&lt;model xmlns="http://namespaces.plone.org/supermodel/schema"&gt; &lt;schema&gt; &lt;field name="title" type="zope.schema.TextLine"&gt; &lt;description /&gt; &lt;title&gt;Name&lt;/title&gt; &lt;/field&gt; &lt;field name="portrait" type="plone.namedfile.field.NamedBlobImage"&gt; &lt;title&gt;Portrait&lt;/title&gt; &lt;/field&gt; &lt;field name="bio" type="plone.app.textfield.RichText"&gt; &lt;title&gt;Bio&lt;/title&gt; &lt;/field&gt; &lt;/schema&gt; &lt;/model&gt;</property> <property name="model_file"></property>

(These are the Dexterity-specifc bits.)

Can put model in a separate fle.

Can put model in a Zope 3 schema.

plonista.xml (continued)

<alias from="(Default)" to="(selected layout)"/> <alias from="edit" to="@@edit"/> <alias from="sharing" to="@@sharing"/> <alias from="view" to="@@view"/> <action title="View" action_id="view" category="object" condition_expr="" icon_expr="" link_target="" url_expr="string:${object_url}" visible="True"> <permission value="View"/> </action> <action title="Edit" action_id="edit" category="object" condition_expr="" icon_expr="" link_target="" url_expr="string:${object_url}/edit" visible="True"> <permission value="Modify portal content"/> </action></object>

Custom add permission

• In configure.zcml:

• In plonista.xml:

• Add collective.autopermission dependency in setup.py, rerun buildout

<permission id="example.ploneconf09.AddPlonista" title="example.ploneconf09: Add plonista" />

<property name="add_permission">example.ploneconf09.AddPlonista</property>

Using a Zope 3 schema

from zope import schemafrom plone.directives import formfrom plone.namedfile.field import NamedBlobImagefrom plone.app.textfield import RichText

class IPlonista(form.Schema): title = schema.TextLine( title = u'Name', ) portrait = NamedBlobImage( title = u'Portrait', required = False, ) bio = RichText( title=u'Bio', required = False, )

• In plonista.py:

Using a Zope 3 Schema• In configure.zcml:

• Add five.grok to dependencies in setup.py• In plonista.xml:

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

<property name="schema">example.ploneconf09.plonista.IPlonista</property> <property name="model_source"></property>

Specifying a fieldset

class IPlonista(form.Schema): … bio = RichText( title=u'Bio', required = False, ) form.fieldset( 'bio', label=u'Bio', fields=['bio'], )

More form directives

• widget – specify alternate widget• omitted – omits fields• mode – input, display, or hidden• order_before, order_after – adjust position

plone.directives.dexterity

• read_permission• write_permission

Custom view template

• In plonista.py:

from five import grokclass View(grok.View): grok.context(IPlonista) grok.require('zope2.View')

• In plonista_templates/view.pt<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" xmlns:tal="http://xml.zope.org/namespaces/tal" xmlns:metal="http://xml.zope.org/namespaces/metal" xmlns:i18n="http://xml.zope.org/namespaces/i18n" lang="en" metal:use-macro="context/main_template/macros/master" i18n:domain="example.conference"><body><metal:main fill-slot="main"> <tal:main-macro metal:define-macro="main"> <div tal:replace="structure provider:plone.abovecontenttitle" /> <h1 class="documentFirstHeading" tal:content="context/title" /> <div tal:replace="structure provider:plone.belowcontenttitle" /> <div tal:replace="structure provider:plone.abovecontentbody" /> <div tal:define="portrait nocall:context/portrait" tal:condition="nocall:portrait"><imgtal:attributes="src string:${context/absolute_url}/@@download/portrait/${portrait/filename}; height portrait/_height | nothing; width portrait/_width | nothing;" /> </div> <div tal:content="structure context/bio/output" /> <div tal:replace="structure provider:plone.belowcontentbody" /> </tal:main-macro></metal:main></body></html>

Add the package to buildout[buildout]develop = src/example.ploneconf09

[instance]… eggs = … example.ploneconf09

Install the new package

Existing content automatically provides the new schema

The custom view

The pieces

http://www.fickr.com/photos/intvgene/370973576/

five.grok

• Allows for writing configuration directives in Python and in place, instead of using ZCML.

• “Grok” a package using the following ZCML, and it will register anything its grokkers find and recognize.

<grok:grok package="." />

plone.dexterity

• Base content classes.• FTI (Factory Type Information)

provides for dynamic lookupof model and schema.

• Default edit form and view.

plone.autoform

• Dexterity renders widgets using z3c.form.• Plone.autoform makes it possible for a form

to be composed by schemas and form hints from different sources.(Main schema + behavior schemas, in the case of Dexterity.)

plone.schemaeditor

• Provides the UI for editing Zope 3 interfaces through the web.

• Dexterity integrates it with the Dexterity types control panel, but it could be used separately.

• IFieldFactory lookup determines what fields can be edited.

plone.supermodel

• Serializer translates a Zope 3 schema into XML.

• Parser translates an XML schema into a Zope 3 schema.

• Easily extensible» Field handlers found via adapter lookup» Additional metadata handlers may handle

custom XML namespaces

plone.directives.form

• Defines the form rendering hint directives that may be included in schemas for use by plone.autoform when rendering forms and views.

plone.directives.dexterity

• Grok directives for custom content classes and forms.

plone.folder

• Orderable Btree-based folder implementation.

• Will also be the basis for AT-based folders in Plone 4.

plone.behavior

• A behavior is a conditional adapter.• In Dexterity, the condition is whether the

behavior is listed in the FTI for an item.• ZCML directive for registering new

behaviors.

plone.rfc822

• Supports the marshalling of Dexterity content into RFC 822 format.

• Used to support access via WebDAV.

plone.app.dexterity

• Pulls in everything you need.• Standard behaviors.» Dublin Core» Related Items

• Dexterity types control panel.

Status report / roadmap

http://www.fickr.com/photos/brianatwebbmoto/2392041992/sizes/m/

Core functionality

Schema serialization

Automatic formgeneration

Portlet assignments

Content rules

Relations

• Not working between Archetypes and Dexterity content in the same site

Widgets

• Not as rich as Archetypes yet, but better than formlib. We have autocomplete, browse-for-content, file/image upload.

TTW schema editing

• Works fine, but needs more real-life use.

Image & file support

(via plone.namedfile & plone.formwidget.namedfile)

• No support for image scaling yet.

Text transform support

(via plone.app.textfield)

Select field support

• No way to define vocabularies through the web yet.

WebDAV support

Versioning & staging

• In progress

TTW behavior creation

Automatic migrationfrom Archetypescontent

Multi-lingual content

• Some discussion, but no code yet.

Link integrity checks

Upcoming releases

• Second alpha release was on Oct. 12• First beta release coming soon

Compatibility

• Plone 3• Plone 4 compatibility coming soon

Performance

Further information

• Dexterity manual:http://plone.org/products/dexterity/documentation/manual/developer-manual

• Behaviors manual:http://plone.org/products/dexterity/documentation/manual/behaviors

• Over 30,000 words!

Example Code

• example.dexterity• example.conference

(both in the collective)

• Example code from this talk:http://svn.plone.org/svn/plone/plone.dexterity/example.ploneconf09

Thanks to everyone who has contributed to making Dexterity a reality!

http://www.fickr.com/photos/torley/2862255105/

Getting involved

• Google Code project:http://code.google.com/p/dexterity/

• Google Group:http://groups.google.com/group/dexterity-development