Dexterity XML

A reference for Dexterity's XML name spaces

Introduction

The schema (structure) of a Dexterity content type may be detailed in two very different ways:

  • In Python as a Zope schema; or,
  • In XML

When you are using Dexterity's through-the-web schema editor, all your work is being saved in the content type's Factory Type Information (FTI) as XML. plone.supermodel dynamically translates that XML into Python objects which are used to display and edit your content objects.

The XML model of your content object may be exported from Dexterity and incorporated into a Python package. That's typically done with code like:

class IExampleType(form.Schema):

    form.model("models/example_type.xml")

or:

from plone.supermodel import xmlSchema

IExampleType = xmlSchema("models/example_type.xml")

XML models in a package may be directly edited.

This document is a reference to the tags and attributes you may use in model XML files. This includes several form-control and security-control attributes that are not available through the TTW schema editor.

XML Document Structure

Dexterity requires that its model XML be well-formed XML, including name space declarations. The typical structure of a Dexterity XML document is:

<?xml version="1.0" encoding="UTF-8"?>
<model xmlns="http://namespaces.plone.org/supermodel/schema"
       xmlns:form="http://namespaces.plone.org/supermodel/form"
       xmlns:security="http://namespaces.plone.org/supermodel/security">
    <schema>
        <field type="zope.schema.TextLine" name="one">
            <title>One</title>
            ... More field attributes
        </field>
        ... More fields
    </schema>
</model>

Only the default name space (.../supermodel/schema) is required for basic schema. The supermodel/form and supermodel/schema provide additional attributes to control form presentation and security.

supermodel/schema fields

Most of the supermodel/schema field tag and its attributes map directly to what's available via the TTW schema editor:

<field name="dummy" type="zope.schema.TextLine">
  <default>abc</default>
  <description>Test desc</description>
  <max_length>10</max_length>
  <min_length>2</min_length>
  <missing_value>m</missing_value>
  <readonly>True</readonly>
  <required>False</required>
  <title>Test</title>
</field>

The field type needs to be the full dotted name (as if it was being imported in Python) of the field type.

Fieldsets

It's easy to add fieldsets by surrounding embedding fields tags in a fieldset block:

<schema>
  ...
  <fieldset name="test"
          label="Test Fieldset"
          description="Description of test fieldset">
      <field name="three" type="zope.schema.TextLine">
        <description/>
        <title>Three</title>
      </field>
      <field name="four" type="zope.schema.TextLine">
        <description/>
        <title>Four</title>
      </field>
  </fieldset>
  ...
</schema>

Vocabularies

Vocabularies may be specified via dotted names using the source tag:

<field name="dummy" type="zope.schema.Choice">
    <default>a</default>
    <description>Test desc</description>
    <missing_value/>
    <readonly>True</readonly>
    <required>False</required>
    <title>Test</title>
    <source>plone.supermodel.tests.dummy_vocabulary_instance</source>
</field>

Where the full Python dotted-name of a Zope vocabulary in a package:

from zope.schema.vocabulary import SimpleVocabulary

dummy_vocabulary_instance = SimpleVocabulary.fromItems([(1, 'a'), (2, 'c')])

Or, a source binder:

<field name="dummy" type="zope.schema.Choice">
    ...
    <source>plone.supermodel.tests.dummy_binder</source>
</field>

With Python like:

from zope.schema.interfaces import IContextSourceBinder

class Binder(object):
    implements(IContextSourceBinder)

    def __call__(self, context):
        return SimpleVocabulary.fromValues(['a', 'd', 'f'])

dummy_binder = Binder()

You may also use the vocabulary tag rather than source to refer to named vocabularies registered via the ZCA.

Internationalization

Translation domains and message ids can be specified for text that is interpreted as unicode. This will result in deserialization as a zope.i18nmessageid message id rather than a basic Unicode string.

Note that we need to add the i18n namespace and a domain specification:

<model xmlns="http://namespaces.plone.org/supermodel/schema"
       xmlns:i18n="http://xml.zope.org/namespaces/i18n"
       i18n:domain="your.application">
    <schema>

        <field type="zope.schema.TextLine" name="title">
            <title i18n:translate="yourapp_test_title">Title</title>
        </field>

    </schema>
</model>

supermodel/form attributes

supermodel/form provides attributes that govern presentation and editing.

after/before

To re-order fields, use form:after or form:before.

The value should be either '*', to put the field first/last in the form, or the name of a another field. Use '.fieldname' to refer to field in the current schema (or a base schema). Use a fully prefixed name (e.g. 'my.package.ISomeSchema') to refer to a field in another schema. Use an unprefixed name to refer to a field in the default schema for the form.

Example:

<field type="zope.schema.TextLine"
       name="one"
       form:after="two">
    <title>One</title>
</field>

mode

To turn a field into a view mode or hidden field, use form:mode. The mode may be set for only some forms by specifying a form interface in the same manner as for form:omitted.

Example:

<field type="zope.schema.TextLine"
        name="three"
        form:mode="z3c.form.interfaces.IEditForm:input">
    <title>Three</title>
</field>

omitted

To omit a field from all forms, use form:omitted="true". To omit a field only from some forms, specify a form interface like form:omitted="z3c.form.interfaces.IForm:true". Multiple interface:value settings may be specified, separated by spaces.

Examples:

<field type="zope.schema.TextLine"
       name="one"
       form:omitted="true">
    <title>One</title>
</field>

<field type="zope.schema.TextLine" name="three"
        form:omitted="z3c.form.interfaces.IForm:true z3c.form.interfaces.IEditForm:false"
        >
    <title>Three</title>
</field>

The latter example hides the field on everything except the edit form.

widget

To set a custom widget for a field, use form:widget to give a fully qualified name to the field widget factory.

Example:

<field type="zope.schema.TextLine"
       name="password"
       form:widget="z3c.form.browser.password.PasswordFieldWidget">
    <title>One</title>
</field>

Dynamic Defaults

To set a dynamic default for a field, use a defaultFactory tag to give a fully qualified name for a callable. The defaultFactory callable must provide either plone.supermodel.interfaces.IDefaultFactory or zope.schema.interfaces.IContextAwareDefaultFactory.

Example:

<field type="zope.schema.TextLine" name="three">
    <title>Three</title>
    <defaultFactory>plone.supermodel.tests.dummy_defaultFactory</defaultFactory>
</field>

Sample Python for the validator factory:

@provider(IDefaultFactory)
def dummy_defaultFactory():
    return u'something'

For a callable using context:

@provider(IContextAwareDefaultFactory)
def dummy_defaultCAFactory(context):
    return context.something

Note

The defaultFactory tag was added in plone.supermodel 1.2.3, shipping with Plone 4.3.2+.

validator

To set a custom validator for a field, use form:validator to give a fully qualified name to the field validator factory. The validator factory should be a class derived from one of the validators in z3c.form.validator.

Example:

<field type="zope.schema.TextLine"
        name="three"
        form:validator="plone.autoform.tests.test_utils.TestValidator">
    <title>Three</title>
</field>

Sample Python for the validator factory:

class TestValidator(z3c.form.validator.SimpleFieldValidator):

    def validate(self, value):
        super(TestValidator, self).validate(value)
        raise Invalid("Test")

supermodel/security attributes

read-permission/write-permission

To set a read or write permission, use security:read-permission or security:write-permission. The value should be the name of an IPermission utility.

Example:

<field type="zope.schema.TextLine"
        name="one"
        security:read-permission="zope2.View"
        security:write-permission="cmf.ModifyPortalContent">
    <title>One</title>
</field>