22. Dexterity: Reference¶

This chapter documents all types fields, widgets, directives that you can use with dexterity.

22.1. Fields included in Plone¶

This is a schema with examples for all field-types that are shipped with Plone by default. They are arranged in fieldsets:

Default: Textline, Text, Boolean, Richtext (html), Email
Number fields: Integer, Float
Date and time fields: Datetime, Date, Time, Timedelta
Choice and Multiple Choice fields: Choice, Choice with radio widget, Choice with Select2 widget, Choice with named vocabulary, List, List with checkboxes, List with Select2 widget, List with values from named vocabulary but open to additions, Tuple, Set, Set with checkboxes
Relation fields: Relationchoice, Relationlist
File fields: File, Image
Other fields: Uri, Sourcetext, Ascii, Bytesline, Asciiline, Pythonidentifier, Dottedname, Dict, Dict with Choice

Warning

In Volto not all field types and features are implemented yet:

Time, Timedelta, Dict are not supported yet.
Using a callable for basePath in relationfields is not supported yet.
The schema-hints to assign a different widget do not work yet.

from plone.app.multilingual.browser.interfaces import make_relation_root_path
from plone.app.textfield import RichText
from plone.app.z3cform.widget import AjaxSelectFieldWidget
from plone.app.z3cform.widget import RelatedItemsFieldWidget
from plone.app.z3cform.widget import SelectFieldWidget
from plone.autoform import directives
from plone.dexterity.content import Container
from plone.namedfile.field import NamedBlobFile
from plone.namedfile.field import NamedBlobImage
from plone.schema.email import Email
from plone.supermodel import model
from plone.supermodel.directives import fieldset
from plone.supermodel.directives import primary
from z3c.form.browser.checkbox import CheckBoxFieldWidget
from z3c.form.browser.radio import RadioFieldWidget
from z3c.relationfield.schema import Relation
from z3c.relationfield.schema import RelationChoice
from z3c.relationfield.schema import RelationList
from zope import schema
from zope.interface import implementer


class IExample(model.Schema):
    """Dexterity-Schema with all field-types."""

    # The most used fields
    # textline, text, bool, richtext, email

    fieldset(
        'numberfields',
        label='Number fields',
        fields=('int_field', 'float_field'),
    )

    fieldset(
        'datetimefields',
        label='Date and time fields',
        fields=('datetime_field', 'date_field', 'time_field', 'timedelta_field'),
    )

    fieldset(
        'choicefields',
        label='Choice and Multiple Choice fields',
        fields=(
            'choice_field',
            'choice_field_radio',
            'choice_field_select',
            'choice_field_voc',
            'list_field',
            'list_field_checkbox',
            'list_field_select',
            'list_field_voc_unconstrained',
            'tuple_field',
            'set_field',
            'set_field_checkbox',
        ),
    )

    fieldset(
        'relationfields',
        label='Relation fields',
        fields=('relationchoice_field', 'relationlist_field'),
    )

    fieldset(
        'filefields',
        label='File fields',
        fields=('file_field', 'image_field'),
    )

    fieldset(
        'otherfields',
        label='Other fields',
        fields=(
            'uri_field',
            'sourcetext_field',
            'ascii_field',
            'bytesline_field',
            'asciiline_field',
            'pythonidentifier_field',
            'dottedname_field',
            'dict_field',
            'dict_field_with_choice',
        ),
    )

    primary('title')
    title = schema.TextLine(
        title='Primary Field (Textline)',
        required=True,
    )

    text_field = schema.Text(
        title='Text Field',
        required=False,
        missing_value='',
    )

    textline_field = schema.TextLine(
        title='Textline field',
        description='A simple input field',
        required=False,
    )

    bool_field = schema.Bool(
        title='Boolean field',
        required=False,
    )

    choice_field = schema.Choice(
        title='Choice field',
        values=['One', 'Two', 'Three'],
        required=True,
    )

    directives.widget(choice_field_radio=RadioFieldWidget)
    choice_field_radio = schema.Choice(
        title='Choice field with radio boxes',
        values=['One', 'Two', 'Three'],
        required=True,
    )

    choice_field_voc = schema.Choice(
        title='Choicefield with values from named vocabulary',
        vocabulary='plone.app.vocabularies.PortalTypes',
        required=False,
    )

    directives.widget(choice_field_select=SelectFieldWidget)
    choice_field_select = schema.Choice(
        title='Choicefield with select2 widget',
        vocabulary='plone.app.vocabularies.PortalTypes',
        required=False,
    )

    list_field = schema.List(
        title='List field',
        value_type=schema.Choice(
            values=['Beginner', 'Advanced', 'Professional'],
        ),
        required=False,
        missing_value=[],
    )

    directives.widget(list_field_checkbox=CheckBoxFieldWidget)
    list_field_checkbox = schema.List(
        title='List field with checkboxes',
        value_type=schema.Choice(
            values=['Beginner', 'Advanced', 'Professional'],
        ),
        required=False,
        missing_value=[],
    )

    directives.widget(list_field_select=SelectFieldWidget)
    list_field_select = schema.List(
        title='List field with select widget',
        value_type=schema.Choice(
            values=['Beginner', 'Advanced', 'Professional'],
        ),
        required=False,
        missing_value=[],
    )

    list_field_voc_unconstrained = schema.List(
        title='List field with values from vocabulary but not constrained to them.',
        value_type=schema.TextLine(),
        required=False,
        missing_value=[],
    )
    directives.widget(
        'list_field_voc_unconstrained',
        AjaxSelectFieldWidget,
        vocabulary='plone.app.vocabularies.Users',
    )

    tuple_field = schema.Tuple(
        title='Tuple field',
        value_type=schema.Choice(
            values=['Beginner', 'Advanced', 'Professional'],
        ),
        required=False,
        missing_value=(),
    )

    set_field = schema.Set(
        title='Set field',
        value_type=schema.Choice(
            values=['Beginner', 'Advanced', 'Professional'],
        ),
        required=False,
        missing_value={},
    )

    directives.widget(set_field_checkbox=CheckBoxFieldWidget)
    set_field_checkbox = schema.Set(
        title='Set field with checkboxes',
        value_type=schema.Choice(
            values=['Beginner', 'Advanced', 'Professional'],
        ),
        required=False,
        missing_value={},
    )

    # File fields
    image_field = NamedBlobImage(
        title='Image field',
        description='A upload field for images',
        required=False,
    )

    file_field = NamedBlobFile(
        title='File field',
        description='A upload field for files',
        required=False,
    )

    # Date and Time fields
    datetime_field = schema.Datetime(
        title='Datetime field',
        description='Uses a date and time picker',
        required=False,
    )

    date_field = schema.Date(
        title='Date field',
        description='Uses a date picker',
        required=False,
    )

    time_field = schema.Time(
        title='Time field',
        required=False,
    )

    timedelta_field = schema.Timedelta(
        title='Timedelta field',
        required=False,
    )

    # Relation Fields
    relationchoice_field = RelationChoice(
        title='Relationchoice field',
        vocabulary='plone.app.vocabularies.Catalog',
        required=False,
    )
    directives.widget(
        'relationchoice_field',
        RelatedItemsFieldWidget,
        pattern_options={
            'selectableTypes': ['Document'],
            'basePath': make_relation_root_path,
        },
    )

    relationlist_field = RelationList(
        title='Relationlist Field',
        default=[],
        value_type=RelationChoice(vocabulary='plone.app.vocabularies.Catalog'),
        required=False,
        missing_value=[],
    )
    directives.widget(
        'relationlist_field',
        RelatedItemsFieldWidget,
        pattern_options={
            'selectableTypes': ['Document'],
            'basePath': make_relation_root_path,
        },
    )

    # Number fields
    int_field = schema.Int(
        title='Integer Field (e.g. 12)',
        description='Allocated (maximum) number of objects',
        required=False,
    )

    float_field = schema.Float(
        title='Float field (e.g. 12.2)',
        required=False,
    )

    # Text fields
    email_field = Email(
        title='Email field',
        description='A simple input field for a email',
        required=False,
    )

    uri_field = schema.URI(
        title='URI field',
        description='A simple input field for a URLs',
        required=False,
    )

    richtext_field = RichText(
        title='RichText field',
        description='This uses a richtext editor.',
        max_length=2000,
        required=False,
    )

    sourcetext_field = schema.SourceText(
        title='SourceText field',
        required=False,
    )

    ascii_field = schema.ASCII(
        title='ASCII field',
        required=False,
    )

    bytesline_field = schema.BytesLine(
        title='BytesLine field',
        required=False,
    )

    asciiline_field = schema.ASCIILine(
        title='ASCIILine field',
        required=False,
    )

    pythonidentifier_field = schema.PythonIdentifier(
        title='PythonIdentifier field',
        required=False,
    )

    dottedname_field = schema.DottedName(
        title='DottedName field',
        required=False,
    )

    dict_field = schema.Dict(
        title='Dict field',
        required=False,
        key_type=schema.TextLine(
            title='Key',
            required=False,
        ),
        value_type=schema.TextLine(
            title='Value',
            required=False,
        ),
    )

    dict_field_with_choice = schema.Dict(
        title='Dict field with key and value as choice',
        required=False,
        key_type=schema.Choice(
            title='Key',
            values=['One', 'Two', 'Three'],
            required=False,
        ),
        value_type=schema.Set(
            title='Value',
            value_type=schema.Choice(
                values=['Beginner', 'Advanced', 'Professional'],
            ),
            required=False,
            missing_value={},
        ),
    )


@implementer(IExample)
class Example(Container):
    """Example instance class"""

22.2. How fields look like¶

22.2.1. Backend¶

This is how these fields look like when editing content in the backend:

Default fields¶

Number fields¶

Date and time fields¶

Choice and multiple choice fields¶

File fields¶

Reference fields¶

Other fields including the dict field¶

22.2.2. Frontend¶

This is how these fields look like when editing content in Volto:

Default fields¶

Number fields¶

Date and time fields¶

Choice and multiple choice fields¶

File fields¶

Reference fields¶

Other fields¶

22.3. 3rd party fields¶

To control the avilable values of other fields or hide/show them based on user input use the Masterselect Field.
For spam-protection use collective.z3cform.norobots.
Color-Picker collective.z3cform.colorpicker
There is no Computedfield but most use-cases can be achieved with a readonly-field and a property. See the discussion

22.4. Datagrid Field¶

The datagrid field allows you to enter multiple values at once as rows in a table. Each row is a sub form defined in a separate schema.

Note

The datagrid field is for Plone Classic. See the mixedfield below, if you are working with Plone.

Here is an example:

from collective.z3cform.datagridfield import DataGridFieldFactory
from collective.z3cform.datagridfield import DictRow
from plone.app.z3cform.widget import SelectFieldWidget
from plone.autoform import directives
from plone.supermodel import model
from zope import schema
from zope.interface import Interface


class IMyRowSchema(Interface):

    choice_field = schema.Choice(
        title='Choice Field',
        vocabulary='plone.app.vocabularies.PortalTypes',
        required=False,
        )
    directives.widget('objective', SelectFieldWidget)

    textline_field = schema.TextLine(
        title='Textline field',
        required=False,
        )

    bool_field = schema.Bool(
        title='Boolean field',
        required=False,
    )


class IExampleWithDatagrid(model.Schema):

    title = schema.TextLine(title='Title', required=True)

    datagrid_field = schema.List(
        title='Datagrid field',
        value_type=DictRow(title='Table', schema=IMyRowSchema),
        default=[],
        required=False,
    )
    directives.widget('datagrid_field', DataGridFieldFactory)

The edit-form looks like this:

../_images/dexterity_reference_datagridfield_edit1.png

The output looks like this:

../_images/dexterity_reference_datagridfield_view1.png

22.5. mixedfield¶

The mixedfield empowers your user to create a list of objects of mixed value types sharing the same schema. If you are familliar with the Plone Classic datagrid field this is the complementary field / widget combo for Plone. mixedfield is a combination of a Plone Classic JSONField and a widget for Plone. Nothing new, just a term to talk about linking backend and frontend.

Example is a custom history:

22.5.1. Backend¶

Add a field history_field to your content type schema.

MIXEDFIELD_SCHEMA = json.dumps(
    {
        'type': 'object',
        'properties': {'items': {'type': 'array', 'items': {'type': 'object', 'properties': {}}}},
    }
)

class IExample(model.Schema):
    """Dexterity-Schema"""

    fieldset(
        'datagrid',
        label='Datagrid field',
        fields=(
            # 'datagrid_field',
            'mixed_field',
            ),
    )

    primary('title')
    title = schema.TextLine(
        title='Primary Field (Textline)',
        description='zope.schema.TextLine',
        required=True,
        )

    description = schema.TextLine(
        title='Description (Textline)',
        description='zope.schema.TextLine',
        required=False,
        )

    history_field = JSONField(
        title='Mixedfield: datagrid field for Plone',
        required=False,
        schema=MIXEDFIELD_SCHEMA,
        widget='history_widget',
        default={'items': []},
        missing_value={'items': []},
        )

22.5.2. Frontend¶

Provide a widget in your favorite add-on with a schema of elementary fields you need.

import React from 'react';

import ObjectListWidget from '@plone/volto/components/manage/Widgets/ObjectListWidget';

const ItemSchema = {
    title: 'History-Entry',
    properties: {
        historydate: {
            title: 'Date',
            widget: 'date',
        },
        historytopic: {
            title: 'What',
        },
        historyversion: {
            title: 'Version',
        },
        historyauthor: {
            title: 'Who',
        },
    },
    fieldsets: [
        {
            id: 'default',
            title: 'History-Entry',
            fields: [
                'historydate',
                'historytopic',
                'historyversion',
                'historyauthor',
            ],
        },
    ],
    required: [],
};

const HistoryWidget = (props) => {
    return (
        <ObjectListWidget
            schema={ItemSchema}
            {...props}
            value={props.value?.items || props.default?.items || []}
            onChange={(id, value) => props.onChange(id, { items: value })}
        />
    );
};

export default HistoryWidget;

Keeping this example as simple as possible we skipped the localization. Please see Volto documentation for details.

Register this widget for the backend field of your choice in your apps configuration config.js. The following config code registers the custom Plone HistoryWidget for Plone Classic fields with widget "history_widget".

import { HistoryWidget } from '@rohberg/voltotestsomevoltothings/components';

// All your imports required for the config here BEFORE this line
import '@plone/volto/config';

export default function applyConfig(config) {
    config.settings = {
        ...config.settings,
        supportedLanguages: ['en', 'de', 'it'],
        defaultLanguage: 'en',
    };
    config.widgets.widget.history_widget = HistoryWidget;

    return config;
}

Please be sure to use plone.restapi version >= 7.3.0. If you cannot upgrade plone.restapi then a registration per field id instead of a registration per field widget name is needed.

export default function applyConfig(config) {
  config.widgets.id.history_field = HistoryWidget;
  return config;
}

The user can now edit the values of the new field history_field.

Thats what you did to accomplish this:

You added a new field of type JSONField with widget "history_widget" and default schema to your content type schema.
You registered the custom Plone widget for widget name "history_widget".

A view (ExampleView) of the content type integrates a component to display the values of the field history_field.

import React from 'react';
import moment from 'moment';
import { Container, Table } from 'semantic-ui-react';

const MyHistory = ({ history }) => {
    return (
        _CLIENT__ && (
        <Table celled className="history_list">
            <Table.Header>
            <Table.Row>
                <Table.HeaderCell>Date</Table.HeaderCell>
                <Table.HeaderCell>What</Table.HeaderCell>
                <Table.HeaderCell>Version</Table.HeaderCell>
                <Table.HeaderCell>Who</Table.HeaderCell>
            </Table.Row>
            </Table.Header>

            <Table.Body>
            {history?.items?.map((item) => (
                <Table.Row>
                <Table.Cell>
                    {item.historydate && moment(item.historydate).format('L')}
                </Table.Cell>
                <Table.Cell>{item.historytopic}</Table.Cell>
                <Table.Cell>{item.historyversion}</Table.Cell>
                <Table.Cell>{item.historyauthor}</Table.Cell>
                </Table.Row>
            ))}
            </Table.Body>
        </Table>
        )
    );
};

const ExampleView = ({ content }) => {
    return (
        <Container>
        <h2>I am an ExampleView</h2>
        <h3>History</h3>
        <MyHistory history={content.history_field} />
        </Container>
    );
 };

 export default ExampleView;

Et voilà.

22.6. Widgets¶

22.7. Directives¶

Directives can be placed anywhere in the class body (annotations are made directly on the class). By convention they are kept next to the fields they apply to.

For example, here is a schema that omits a field:

from plone.autoform import directives
from plone.supermodel import model
from zope import schema


class ISampleSchema(model.Schema):

    title = schema.TextLine(title='Title')

    directives.omitted('additionalInfo')
    additionalInfo = schema.Bytes()

You can also handle multiple fields with one directive:

directives.omitted('field_1', 'field_2')

With the directive "mode" you can set fields to 'input', 'display' or 'hidden'.

directives.mode(additionalInfo='hidden')

You can apply directives to certain forms only. Here we drop a field from the add-form, it will still show up in the edit-form.

from z3c.form.interfaces import IAddForm

class ITask(model.Schema):

    title = schema.TextLine(title='Title')

    directives.omitted(IAddForm, 'done')
    done = schema.Bool(
        title='Done',
        required=False,
    )

The same works for custom forms.

With the directive widget() you can not only change the widget used for a field. With pattern_options you can pass additional parameters to the widget. Here, we configure the datetime widget powered by the JavaScript library pickadate by adding options that are used by it. Plone passes the options to the library.

class IMeeting(model.Schema):

    meeting_date = schema.Datetime(
        title='Date and Time',
        required=False,
    )
    directives.widget(
        'meeting_date',
        DatetimeFieldWidget,
        pattern_options={
            'time': {'interval': 60, 'min': [7, 0], 'max': [19, 0]}},
    )

22.7.1. Validation and default values¶

In the following example we add a validator and a default value.

from zope.interface import Invalid
import datetime


def future_date(value):
    if value and not value.date() >= datetime.date.today():
        raise Invalid('Meeting date can not be before today.')
    return True


def meeting_date_default_value():
    return datetime.datetime.today() + datetime.timedelta(7)


class IMeeting(model.Schema):

    meeting_date = schema.Datetime(
        title='Date and Time',
        required=False,
        constraint=future_date,
        defaultFactory=meeting_date_default_value,
    )

Validators and defaults can be also be made aware of the context (i.e. to check against the values of other fields).

For context aware defaults you need to use a IContextAwareDefaultFactory. It will be passed the container for which the add form is being displayed:

from zope.interface import provider
from zope.schema.interfaces import IContextAwareDefaultFactory


@provider(IContextAwareDefaultFactory)
def get_container_id(context):
    return context.id.upper()


class IMySchema(model.Schema):

    parent_id = schema.TextLine(
        title='Parent ID',
        required=False,
        defaultFactory=get_container_id,
    )

For context-aware validators you need to use invariant():

from zope.interface import Invalid
from zope.interface import invariant
from zope.schema.interfaces import IContextAwareDefaultFactory


class IMyEvent(model.Schema):

    start = schema.Datetime(
        title='Start date',
        required=False,
    )

    end = schema.Datetime(
        title='End date',
        required=False,
    )

    @invariant
    def validate_start_end(data):
        if data.start is not None and data.end is not None:
            if data.start > data.end:
                raise Invalid('Start must be before the end.')

Plone Training 2021 documentation