z3c.form

z3c.form provides an implementation for both HTML and JSON forms and according widgets. Its goal is to provide a simple API but with the ability to easily customize any data or steps.

There are currently two maintained branches:

• master with the latest changes
• 3.x without the object widget overhaul and still including the ObjectSubForm and the SubformAdapter.

Documentation on this implementation and its API can be found at

Changelog

5.1 (2023-07-19)

• HTMLFormElement.attributes: Allow to extend HTML attributes programmatically.

5.0 (2023-07-17)

• Add support for Python 3.11.
• Drop support for Python 2.7, 3.5, 3.6.
• Drop deprecated support for python setup.py test.
• HTMLFormElement.addClass: Improve removal of duplicates. It's now possible to add multiple classes as whitespace separated string and still detect class duplicates.

4.3 (2022-03-24)

• Add support for Python 3.10.
• Update tests to lxml > 4.7, thus requiring at least that version. (#107)
• Remove unused ISubformFactory. (#110 <>`_) [petschki]

4.2 (2021-07-29)

• Fix MultiConverter.toFieldValue tuple typed field support (when field._type is a tuple of types, not a single type).
• Add Python 3.9 compatibility and testing.
• Apply zopefoundation.meta config
• Fix tests for the zope.schema.Bool required default change.
• Fix tests for the zope.interface repr() change.
• Fix compatibility with changed repeat syntax. Fixes issue 94.
• Some fixes in spanish translation. [erral]
• Drop support for Python 3.4.
• Add support for Python 3.8b4.
• Try to fix the buggy hidden mode behaviour of checkbox widgets. Fixes issue 89.

4.1.2 (2019-03-04)

• Fix an edge case when field missing_value is not `None but a custom value that works as None. That ended up calling zope.i18n NumberFormat.format with None` what then failed.

4.1.1 (2018-11-26)

• Fix FieldWidgets.copy(). It was broken since SelectionManager was reimplemented using OrderedDict.

4.1.0 (2018-11-15)

• Add support for Python 3.7.
• Deal with items with same name but different values in ordered field widget. [rodfersou]
• Move homegrown Manager implementation to OrderedDict. [tomgross]
• Adapt tests to lxml >= 4.2, zope.configuration >= 4.3 and zope.schema >= 4.7.

4.0.0 (2017-12-20)

• Upgrade the major version 4 to reflect the breaking changes in 3.3.0. (Version 3.6 will be a re-release of 3.2.x not containing the changes since 3.3.0 besides cherry-picks.) Fixes:

• Host documentation at

3.5.0 (2017-09-19)

• Add support for Python 3.6.
• Drop support for Python 3.3.
• Avoid duplicated IDs when using a non-required field with z3c.formwidget.query.widget.QuerySourceRadioWidget. [pgrunewald]

3.4.0 (2016-11-15)

• Drop support for Python 2.6.
• Support Python 3.5 officially.
• Fix TypeError: object of type 'generator' has no len(). Happens with z3c.formwidget.query. [maurits]
• Turned items into a property again on all widgets. For the select widget it was a method since 2.9.0. For the radio and checkbox widgets it was a method since 3.2.10. For orderedselect and multi it was always a property. Fixes [maurits]
• Fix handling of missing terms in collections. (See version 2.9 describing this feature.)
• Fix orderedselect_input.js resource to be usable on browser layers which do not extend zope.publisher.interfaces.browser.IDefaultBrowserLayer.

3.3.0 (2016-03-09)

• MAJOR overhaul of ObjectWidget:
  • low level unittests passed, but high level was not tops basic rule is that widgets want RAW values and all conversion must be done in ObjectConverter
  • ObjectSubForm and SubformAdapter is removed, it was causing more problems than good
  • added high level integration tests
• Removed z3c.coverage from test extra. [gforcada, maurits]

3.2.10 (2016-03-09)

• RadioWidget items are better determined when they are needed [agroszer]
• CheckBoxWidget items are better determined when they are needed [agroszer]
• Bugfix: The ChoiceTerms adapter blindly assumed that the passed in field is unbound, which is not necessarily the case in interesting ObjectWidget scenarios. Not it checks for a non-None field context first. [srichter]

3.2.9 (2016-02-01)

• Correctly handled noValueToken in RadioWidget. This avoids a LookupError: --NOVALUE--. [gaudenz,ale-rt]
• Added json method for forms and json_data method for widgets. [mmilkin]
• Change javascript for updating ordered select widget hidden structure so it works again on IE11 and doesn't send back an empty list that deletes all selections on save. Fixes [fredvd]
• Started on Dutch translations. [maurits]

3.2.8 (2015-11-09)

• Standardized namespace __init__. [agroszer]

3.2.7 (2015-09-20)

• Remove "cannot move farther up/down" messages in ordered select widget. [esteele]
• Updated Traditional Chinese translation. [l34marr]

3.2.6 (2015-09-10)

• Fixed warnings in headers of locales files. Checked with msgfmt -c. [maurits]
• Added Finnish translation. [petri]
• Added Traditional Chinese translation. [l34marr]

3.2.5 (2015-09-09)

• Fixed error on Python 3: NameError: global name 'basestring' is not defined. This fixes a bug introduced in version 3.2.1. [maurits]

3.2.4 (2015-07-18)

• Fix ordered select input widget not working. [vangheem]
• ReSt fix. [timo]

3.2.3 (2015-03-21)

• 3.2.2 was a brown bag release. Fix MANIFEST.in to include the js file that has been added in 3.2.2. [timo]

3.2.2 (2015-03-21)

• move js to separate file to prevent escaped entities in Plone 5. [pbauer]

3.2.1 (2014-06-09)

• Add DataExtractedEvent, which is thrown after data and errors are extracted from widgets. Fixes

• Remove spaces at start and end of text field values.

• Explicitly hide span in orderedselect_input.pt. This only contains hidden inputs, but Internet Explorer 10 was showing them anyway. Fixes

3.2.0 (2014-03-18)

• Feature: Added text and password widget HTML5 attributes required by plone.login.

3.1.1 (2014-03-02)

• Feature: Added a consistent id on single checkbox and multi checkbox widgets.

3.1.0 (2013-12-02)

• Feature: Added a consistent id on ordered selection widget.
• Feature: Added a hidden template for the textlines widget.
• Feature: added an API to render each radio button separately.

3.0.5 (2013-10-09)

• Bug: Remove errors for cases where the key field of a dict field uses a sequence widget (most notably choices). The sequence widget always returns lists as widget values, which are not hashable. We convert those lists to tuples now within the dict support.

3.0.4 (2013-10-06)

• Feature: Moved registration of translation directories to a separate ZCML file.
• Bug: Fixed a typo in German translations.

3.0.3 (2013-09-06)

• Feature: Version 2.9 introduced a solution for missing terms in vocabularies. Adapted sources to this solution, too.

3.0.2 (2013-08-14)

• Bug: Fix unicode decode error in weird cases in checkbox.CheckboxWidget.update() and radio.RadioWidget.update() (eg: when term.value is an Plone Archetype ATFile)

3.0.1 (2013-06-25)

• Bug: The alpha slipped out as 3.0.0, removed ZODB-4.0.0dev.tar.gz to reduce damage
• Bug: Fixed a bug in widget.py def wrapCSSClass

3.0.0 (2013-06-24)

• Feature: Added support for IDict field in MultiWidget.
• Bug: Only add the 'required' CSS class to widgets when they are in input mode.
• Bug: Catch bug where if a select value was set as from hidden input or through a rest url as a single value, it won't error out when trying to remove from ignored list. Probably not the 100% right fix but it catches core dumps and is sane anyways.

3.0.0a3 (2013-04-08)

• Feature: Updated pt_BR translation.
• Bug: Fixed a bug where file input value was interpeted as UTF-8.

3.0.0a2 (2013-02-26)

• Bug: The 3.0.0a1 release was missing some files (e.g. locales) due to an incomplete MANIFEST.in.

3.0.0a1 (2013-02-24)

• Feature: Removed several parts to be installed by default, since some packages are not ported yet.
• Feature: Added support for Python 3.3.
• Feature: Replaced deprecated zope.interface.implements usage with equivalent zope.interface.implementer decorator.
• Feature: Dropped support for Python 2.4 and 2.5.
• Bug: Make sure the call to the method that returns the default value is made with a field which has its context bound.

2.9.1 (2012-11-27)

• Feautre: The updateWidgets method has received an argument prefix which allows setting the prefix of the field widgets adapter.

  This allows updating the common widgets prefix before the individual widgets are updated, useful for situations where neither a form, nor a widgets prefix is desired.

• Bug: Capitalize the messages 'no value' and 'select a value'. This change has been applied also to the existing translations (where applicable).

• Bug: TextLinesConverter: Do not ignore newlines at the end of the inputted string, thus do not eat blank items

• Bug: TextLinesConverter: toFieldValue(), convert conversion exceptions to FormatterValidationError, for cases like got a string instead of int.

2.9.0 (2012-09-17)

• Feature: Missing terms in vocabularies: this was a pain until now. Now it's possible to have the same (missing) value unchanged on the object with an EditForm after save as it was before editing. That brings some changes with it:
  • MAJOR: unchanged values/fields do not get validated anymore (unless they are empty or are FileUploads)
  • A temporary SimpleTerm gets created for the missing value Title is by default "Missing: ${value}". See MissingTermsMixin.
• Feature: Split configure.zcml
• Bug: SequenceWidget DISPLAY_MODE: silently ignore missing tokens, because INPUT_MODE and HIDDEN_MODE does that too.

2.8.2 (2012-08-17)

• Feature: Added IForm.ignoreRequiredOnValidation, IWidgets.ignoreRequiredOnValidation, IWidget.ignoreRequiredOnValidation. Those enable extract and extractData to return without errors in case a required field is not filled. That also means the usual "Missing value" error will not get displayed. But the required-info (usually the *) yes. This is handy to store partial state.

2.8.1 (2012-08-06)

• Fixed broken release, my python 2.7 windows setup didn't release the new widget.zcml, widget_layout.pt and widget_layout_hidden.pt files. After enhance the pattern in MANIFEST.in everything seems fine. That's probably because I patched my python version with the *build exclude pattern patch. And yes, the new files where added to the svn repos! After deep into this again, it seems that only previous added *.txt, *.pt files get added to the release. A fresh checkout sdist release only contains the *.py and *.mo files. Anyway the enhanced MANIFEST.in file solved the problem.

2.8.0 (2012-08-06)

• Feature: Implemented widget layout concept similar to z3c.pagelet. The new layout concept allows to register layout templates additional to the widget templates. Such a layout template only get used if a widget get called. This enhacement is optional and compatible with all previous z3c.form versions and doesn't affect existing code and custom implementations except if you implemented a own __call__ method for widgets which wasn't implemented in previous versions. The new __call__ method will lookup and return a layout template which supports additional HTML code used as a wrapper for the HTML code returned from the widget render method. This concept allows to define additional HTML construct provided for all widget and render specific CSS classes arround the widget per context, view, request, etc discriminators. Such a HTML constuct was normaly supported in form macros which can't get customized on a per widget, view or context base.

  Summary; the new layout concept allows us to define a wrapper CSS elements for the widget element (label, widget, error) on a per widgte base and skip the generic form macros offered from z3c.formui.

  Note; you only could get into trouble if you define a widget in tal without to prefix them with nocall: e.g. tal:define="widget view/widgets/foo" Just add a nocall like tal:define="widget nocall:view/widgets/foo" if your rendering engine calls the __call__method by default. Also note that the following will also call the __call__ method tal:define="widget myWidget".

• Fixed content type extraction test which returned different values. This probably depends on a newer version of guess_content_type. Just allow image/x-png and image/pjpeg as valid values.

2.7.0 (2012-07-11)

• Remove zope34 extra, use an older version of z3c.form if you need to support pre-ZTK versions.
• Require at least zope.app.container 3.7 for adding support.
• Avoid dependency on ZODB3.
• Added IField.showDefault and IWidget.showDefault That controls whether the widget should look for field default values to display. This can be really helpful in EditForms, where you don't want to have default values instead of actual (missing) values. By default it is True to provide backwards compatibility.

2.6.1 (2012-01-30)

• Fixed a potential problem where a non-ascii vocabulary/source term value could cause the checkbox and readio widget to crash.
• Fixed a problem with the datetime.timedelta converter, which failed to convert back to the field value, when the day part was missing.

2.6.0 (2012-01-30)

• Remove ":list" from radio inputs, since radio buttons can be only one value by definition. See LP580840.
• Changed radio button and checkbox widget labels from token to value (wrapped by a unicode conversion) to make it consistent with the parent SequenceWidget class. This way, edit and display views of the widgets show the same label. See LP623210.
• Remove dependency on zope.site.hooks, which was moved to zope.component in 3.8.0 (present in ZTK 1.0 and above).
• Make zope.container dependency more optional (it is only used in tests)
• Properly escape JS code in script tag for the ordered-select widget. See LP829484.
• Cleaned whitespace in page templates.
• Fix IGroupForm interface and actually use it in the GroupForm class. See LP580839.
• Added Spanish translation.
• Added Hungarian translation.

2.5.1 (2011-11-26)

• Better compatibility with Chameleon 2.x.
• Added *.mo files missing in version 2.5.0.
• Pinned minimum version of test dependency z3c.template.

2.5.0 (2011-10-29)

• Fixed coverage report generator script buildout setup.

• Note: z3c.pt and chameleon are not fully compatible right now with TAL. Traversing the repeat wrapper is not done the same way. ZPT uses the following pattern: <tal:block condition="not:repeat/value/end">, </tal:block>

  Chameleon only supports python style traversing: <tal:block condition="not:python:repeat['value'].end">, </tal:block>

• Upgrade to chameleon 2.0 template engine and use the newest z3c.pt and z3c.ptcompat packages adjusted to work with chameleon 2.0.

  See the notes from the z3c.ptcompat package:

  Update z3c.ptcompat implementation to use component-based template engine configuration, plugging directly into the Zope Toolkit framework.

  The z3c.ptcompat package no longer provides template classes, or ZCML directives; you should import directly from the ZTK codebase.

  Also, note that the PREFER_Z3C_PT environment option has been rendered obsolete; instead, this is now managed via component configuration.

  Attention: You need to include the configure.zcml file from z3c.ptcompat for enable the z3c.pt template engine. The configure.zcml will plugin the template engine. Also remove any custom built hooks which will import z3c.ptcompat in your tests or other places.

  You can directly use the BoundPageTemplate and ViewPageTempalteFile from zope.browserpage.viewpagetemplatefile if needed. This templates will implicit use the z3c.pt template engine if the z3c.ptcompat configure.zcml is loaded.

2.4.4 (2011-07-11)

• Remove unneeded dependency on deprecated zope.app.security.
• Fixed ButtonActions.update() to correctly remove actions when called again, after the button condition become false.

2.4.3 (2011-05-20)

• Declare TextLinesFieldWidget as an IFieldWidget implementer.
• Clarify MultiWidget.extract(), when there are zero items, this is now [] instead of <NO_VALUE>
• Some typos fixed
• Fixed test failure due to change in floating point representation in Python 2.7.
• Ensure at least min_length widgets are rendered for a MultiWidget in input mode.
• Added Japanese translation.
• Added base of Czech translation.
• Added Portuguese Brazilian translation.

2.4.2 (2011-01-22)

• Adjust test for the contentprovider feature to not depend on the ContentProviderBase class that was introduced in zope.contentprovider 3.5.0. This restores compatibility with Zope 2.10.
• Security issue, removed IBrowserRequest from IFormLayer. This prevents to mixin IBrowserRequest into non IBrowserRequest e.g. IJSONRPCRequest. This should be compatible since a browser request using z3c.form already provides IBrowserRequest and the IFormLayer is only a marker interface used as skin layer.
• Add English translation (generated from translation template using msgen z3c.form.pot > en/LC_MESSAGES/z3c.form.po).
• Added Norwegian translation, thanks to Helge Tesdal and Martijn Pieters.
• Updated German translation.

2.4.1 (2010-07-18)

• Since version 2.3.4 applyChanges required that the value exists when the field had a DictionaryField data manager otherwise it broke with an AttributeError. Restored previous behavior that values need not to be exist before applyChanges was called by using datamanager.query() instead of datamanager.get() to get the previous value.
• Added missing dependency on zope.contentprovider.
• No longer using deprecated zope.testing.doctest by using python's built-in doctest module.

2.4.0 (2010-07-01)

• Feature: mix fields and content providers in forms. This allow to enrich the form by interlacing html snippets produced by content providers. Adding html outside the widgets avoids the systematic need of subclassing or changing the full widget rendering.
• Bug: Radio widget was not treating value as a list in hidden mode.

2.3.4 (2010-05-17)

• Bugfix: applyChanges should not try to compare old and new values if the old value can not be accessed.
• Fix DictionaryField to conform to the IDataManager spec: get() should raise an exception if no value can be found.

2.3.3 (2010-04-20)

• The last discriminator of the 'message' IValue adapter used in the ErrorViewSnippet is called 'content', but it was looked up as the error view itself. It is now looked up on the form's context.
• Don't let util.getSpecification() generate an interface more than once. This causes strange effects when used in value adapters: if two adapters use e.g. ISchema['some_field'] as a "discriminator" for 'field', with one adapter being more specific on a discriminator that comes later in the discriminator list (e.g. 'form' for an ErrorViewMessage), then depending on the order in which these two were set up, the adapter specialisation may differ, giving unexpected results that make it look like the adapter registry is picking the wrong adapter.
• Fix trivial test failures on Python 2.4 stemming from differences in pprint's sorting of dicts.
• Don't invoke render() when publishing the form as a view if the HTTP status code has been set to one in the 3xx range (e.g. a redirect or not-modified response) - the response body will be ignored by the browser anyway.
• Handle Invalid exceptions from constraints and field validators.
• Don't create unnecessary self.items in update() method of SelectWidget in DISPLAY_MODE. Now items is a property.
• Add hidden widget templates for radio buttons and checkboxes.

2.3.2 (2010-01-21)

• Reverted changes made in the previous release as the getContent method can return anything it wants to as long as a data manager can map the fields to it. So context should be used for group instantiation. In cases where context is not wanted, the group can be instantiated in the update method of its parent group or form. See also

  (So version 2.3.2 is the same as version 2.3.0.)

2.3.1 (2010-01-18)

• GroupForm and Group now use getContent method when instantiating group classes instead of directly accessing self.context.

2.3.0 (2009-12-28)

Refactoring

• Removed deprecated zpkg slug and ZCML slugs.
• Adapted tests to zope.schema 3.6.0.
• Avoid to use zope.testing.doctestunit as it is now deprecated.

Update

• Updated German translations.

2.2.0 (2009-10-27)

• Feature: Add z3c.form.error.ComputedErrorViewMessage factory for easy creation of dynamically computed error messages.
• Bug: <div class="error"> was generated twice for MultiWidget and ObjectWidget in input mode.
• Bug: Replace dots with hyphens when generating form id from its name.
• Refactored OutputChecker to its own module to allow using z3c.form.testing without needing to depend on lxml.
• Refactored: Folded duplicate code in z3c.form.datamanager.AttributeField into a single property.

2.1.0 (2009-07-22)

• Feature: The DictionaryFieldManager now allows all mappings (zope.interface.common.mapping.IMapping), even persistent.mapping.PersistentMapping and persistent.dict.PersistentDict. By default, however, the field manager is only registered for dict, because it would otherwise get picked up in undesired scenarios.
• Bug: Updated code to pass all tests on the latest package versions.
• Bug: Completed the Zope 3.4 backwards-compatibility. Also created a buidlout configuration file to test the Zope 3.4 compatibility. Note: You must use the 'latest' or 'zope34' extra now to get all required packages. Alternatively, you can specify the packages listed in either of those extras explicitely in your product's required packages.

2.0.0 (2009-06-14)

Features

• KGS 3.4 compatibility. This is a real hard thing, because z3c.form tests use lxml >= 2.1.1 to check test output, but KGS 3.4 has lxml` 1.3.6. Therefore we agree on that if tests pass with all package versions nailed by KGS 3.4 butlxmloverridden to 2.1.1 then thez3c.form`` package works with a plain KGS 3.4.

• Removed hard z3c.ptcompat and thus z3c.pt dependency. If you have z3c.ptcompat on the Python path it will be used.

• Added nested group support. Groups are rendered as fieldsets. Nested fieldsets are very useful when designing forms.

  WARNING: If your group did have an applyChanges() (or any added(?)) method the new one added by this change might not match the signature.

• Added labelRequired and requiredInfo form attributes. This is useful for conditional rendering a required info legend in form templates. The requiredInfo label depends by default on a given labelRequired message id and will only return the label if at least one widget field is required.

• Add support for refreshing actions after their execution. This is useful when button action conditions are changing as a result of action execution. All you need is to set the refreshActions flag of the form to True in your action handler.

• Added support for using sources. Where it was previosly possible to use a vocabulary it is now also possible to use a source. This works both for basic and contextual sources.

  IMPORTANT: The ChoiceTerms and CollectionTerms in z3c.form.term` are now simple functions that query for realITermsadapters for field'ssourceorvalue_typerespectively. So if your code inherits the oldChoiceTermsandCollectionTermsclasses, you'll need to review and adapt it. See thez3c.form.term`` module and its documentation.

• The new z3c.form.interfaces.NOT_CHANGED special value is available to signal that the current value should be left as is. It's currently handled in the z3c.form.form.applyChanges() function.

• When no file is specified in the file upload widget, instead of overwriting the value with a missing one, the old data is retained. This is done by returning the new NOT_CHANGED special value from the FileUploadDataConvereter.

• Preliminary support for widgets for the schema.IObject field has been added. However, there is a big caveat, please read the object-caveat.txt document inside the package.

  A new objectWidgetTemplate ZCML directive is provided to register widget templates for specific object field schemas.

• Implemented the MultiWidget widget. This widget allows you to use simple fields like ITextLine, IInt, IPassword, etc. in a IList or ITuple sequence.

• Implemented TextLinesWidget widget. This widget offers a text area element and splits lines in sequence items. This is usfull for power user interfaces. The widget can be used for sequence fields (e.g. IList) that specify a simple value type field (e.g. ITextLine or IInt).

• Added a new flag ignoreContext to the form field, so that one can individually select which fields should and which ones should not ignore the context.

• Allow raw request values of sequence widgets to be non-sequence values, which makes integration with Javascript libraries easier.

• Added support in the file upload widget's testing flavor to specify 'base64'-encoded strings in the hidden text area, so that binary data can be uploaded as well.

• Allow overriding the required widget attribute using IValue adapter just like it's done for label and name attributes.

• Add the prompt attribute of the SequenceWidget to the list of adaptable attributes.

• Added benchmarking suite demonstrating performance gain when using z3c.pt.

• Added support for z3c.pt. Usage is switched on via the "PREFER_Z3C_PT" environment variable or via z3c.ptcompat.config.[enable/diable]().

• The TypeError message used when a field does not provide IFormUnicode now also contains the type of the field.

• Add support for internationalization of z3c.form messages. Added Russian, French, German and Chinese translations.

• Sphinx documentation for the package can now be created using the new docs script.

• The widget for fields implementing IChoice is now looked up by querying for an adapter for (field, field.vocabulary, request) so it can be differentiated according to the type of the source used for the field.

• Move formErrorsMessage attribute from AddForm and EditForm to the z3c.form.form.Form base class as it's very common validation status message and can be easily reused (especially when translations are provided).

Refactoring

• Removed compatibility support with Zope 3.3.
• Templates now declare XML namespaces.
• HTML output is now compared using a modified version of the XML-aware output checker provided by lxml.
• Remove unused imports, adjust buildout dependencies in setup.py.
• Use the z3c.ptcompat template engine compatibility layer.

Fixed Bugs

• IMPORTANT - The signature of z3c.form.util.extractFileName function changed because of spelling mistake fix in argument name. The allowEmtpyPostFix is now called allowEmptyPostfix (note Empty instead of Emtpy and Postfix instead of PostFix).
• IMPORTANT - The z3c.form.interfaces.NOVALUE special value has been renamed to z3c.form.interfaces.NO_VALUE to follow the common naming style. The backward-compatibility NOVALUE name is still in place, but the repr output of the object has been also changed, thus it may break your doctests.
• When dealing with Bytes fields, we should do a null conversion when going to its widget value.
• FieldWidgets update method were appending keys and values within each update call. Now the util.Manager uses a UniqueOrderedKeys implementation which will ensure that we can't add duplicated manager keys. The implementation also ensures that we can't override the UniqueOrderedKeys instance with a new list by using a decorator. If this UniqueOrderedKeys implementation doesn't fit for all use cases, we should probably use a customized UserList implementation. Now we can call widgets.update() more then one time without any side effect.
• ButtonActions update where appending keys and values within each update call. Now we can call actions.update() more then one time without any side effect.
• The CollectionSequenceDataConverter no longer throws a TypeError: 'NoneType' object is not iterable when passed the value of a non-required field (which in the case of a List field is None).
• The SequenceDataConverter and CollectionSequenceDataConverter converter classes now ignore values that are not present in the terms when converting to a widget value.
• Use nocall: modifier in orderedselect_input.pt to avoid calling list entry if it is callable.
• SingleCheckBoxFieldWidget doesn't repeat the label twice (once in <div class="label">, and once in the <label> next to the checkbox).
• Don't cause warnings in Python 2.6.
• validator.SimpleFieldValidator is now able to handle interfaces.NOT_CHANGED. This value is set for file uploads when the user does not choose a file for upload.

1.9.0 (2008-08-26)

• Feature: Use the query() method in the widget manager to try extract a value. This ensures that the lookup is never failing, which is particularly helpful for dictionary-based data managers, where dictionaries might not have all keys.
• Feature: Changed the get() method of the data manager to throw an error when the data for the field cannot be found. Added query() method to data manager that returns a default value, if no value can be found.
• Feature: Deletion of widgets from field widget managers is now possible.
• Feature: Groups now produce detailed ObjectModifiedEvent descriptions like regular edit forms do. (Thanks to Carsten Senger for providing a patch.)
• Feature: The widget manager's extract() method now supports an optional setErrors (default value: True) flag that allows one to not set errors on the widgets and widget manager during data extraction. Use case: You want to inspect the entered data and handle errors manually.
• Bug: The ignoreButtons flag of the z3c.form.form.extends() method was not honored. (Thanks to Carsten Senger for providing a patch.)
• Bug: Group classes now implement IGroup. This also helps with the detection of group instantiation. (Thanks to Carsten Senger for providing a patch.)
• Bug: The list of changes in a group were updated incorrectly, since it was assumed that groups would modify mutually exclusive interfaces. Instead of using an overwriting dictionary update() method, a purely additive merge is used now. (Thanks to Carsten Senger for providing a patch.)
• Bug: Added a widget for IDecimal field in testing setup.
• Feature: The z3c.form.util module has a new function, createCSSId() method that generates readable ids for use with css selectors from any unicode string.
• Bug: The applyChanges() method in group forms did not return a changes dictionary, but simply a boolean. This is now fixed and the group form changes are now merged with the main form changes.
• Bug: Display widgets did not set the style attribute if it was available, even though the input widgets did set the style attribute.

1.8.2 (2008-04-24)

• Bug: Display Widgets added spaces (due to code indentation) to the displayed values, which in some cases, like when displaying Python source code, caused the appearance to be incorrect.
• Bug: Prevent to call __len__ on ITerms and use is None for check for existence. Because __len__ is not a part of the ITerms API and not widget.terms will end in calling __len__ on existing terms.

1.8.1 (2008-04-08)

• Bug: Fixed a bug that prohibited groups from having different contents than the parent form. Previously, the groups contents were not being properly updated. Added new documentation on how to use groups to generate object-based sub-forms. Thanks to Paul Carduner for providing the fix and documentation.

1.8.0 (2008-01-23)

• Feature: Implemented IDisplayForm interface.
• Feature: Added integration tests for form interfaces. Added default class attribute called widgets in form class with default value None. This helps to pass the integration tests. Now, the widgets attribute can also be used as a indicator for updated forms.
• Feature: Implemented additional createAndAdd hook in AddForm. This allows you to implement create and add in a single method. It also supports graceful abortion of a create and add process if we do not return the new object. This means it can also be used as a hook for custom error messages for errors happen during create and add.
• Feature: Add a hidden widget template for the ISelectWidget.
• Feature: Arrows in the ordered select widget replaced by named entities.
• Feature: Added CollectionSequenceDataConverter to setupFormDefaults.
• Feature: Templates for the CheckBox widget are now registered in checkbox.zcml.
• Feature: If a value cannot be converted from its unicode representation to a field value using the field's IFromUnicode interface, the resulting type error now shows the field name, if available.
• Bug: createId could not handle arbitrary unicode input. Thanks to Andreas Reuleaux for reporting the bug and a patch for it. (Added descriptive doctests for the function in the process.)
• Bug: Interface invariants where not working when not all fields needed for computing the invariant are in the submitted form.
• Bug: Ordered select didn't submit selected values.
• Bug: Ordered select lists displayed tokens instead of value,
• Bug: SequenceWidget displayed tokens instead of value.

1.7.0 (2007-10-09)

• Feature: Implemented ImageButton, ImageAction, ImageWidget, and ImageFieldWidget to support imge submit buttons.
• Feature: The AttributeField data manager now supports adapting the content to the fields interface when the content doesn't implement this interface.
• Feature: Implemented single checkbox widget that can be used for boolean fields. They are not available by default but can be set using the widgetFactory attribute.
• Bug: More lingual issues have been fixed in the documentation. Thanks to Martijn Faassen for doing this.
• Bug: When an error occurred during processing of the request the widget ended up being security proxied and the system started throwing TraversalError-'s trying to access the label attribute of the widget. Declared that the widgets require the zope.Public permission in order to access these attributes.
• Bug: When rendering a widget the style attribute was not honored. Thanks to Andreas Reuleaux for reporting.
• Bug: When an error occurred in the sub-form, the status message was not set correctly. Fixed the code and the incorrect test. Thanks to Markus Kemmerling for reporting.
• Bug: Several interfaces had the self argument in the method signature. Thanks to Markus Kemmerling for reporting.

1.6.0 (2007-08-24)

• Feature: An event handler for ActionErrorOccurred events is registered to merge the action error into the form's error collectors, such as form.widgets.errors and form.widgets['name'].error (if applicable). It also sets the status of the form. (Thanks to Herman Himmelbauer, who requested the feature, for providing use cases.)
• Feature: Action can now raise ActionExecutionError exceptions that will be handled by the framework. These errors wrap the original error. If an error is specific to a widget, then the widget name is passed to a special WidgetActionExecutionError error. (Thanks to Herman Himmelbauer, who requested the feature, for providing use cases.)
• Feature: After an action handler has been executed, an action executed event is sent to the system. If the execution was successful, the event is ActionSuccessfull event is sent. If an action execution error was raised, the ActionErrorOccurred event is raised. (Thanks to Herman Himmelbauer, who requested the feature, for providing use cases.)
• Feature: The applyChanges() function now returns a dictionary of changes (grouped by interface) instead of a boolean. This allows us to generate a more detailed object-modified event. If no changes are applied, an empty dictionary is returned. The new behavior is compatible with the old one, so no changes to your code are required. (Thanks to Darryl Cousins for the request and implementation.)
• Feature: A new InvalidErrorViewSnippet class provides an error view snippet for zope.interface.Invalid exceptions, which are frequently used for invariants.
• Feature: When a widget is required, HTML-based widgets now declare a "required" class.
• Feature: The validation data wrapper now knows about the context of the validation, which provides a hook for invariants to access the environment.
• Feature: The BoolTerms term tokens are now cosntants and stay the same, even if the label has changed. The choice for the token is "true" and "false". By default it used to be "yes" and "no", so you probably have to change some unit tests. Functional tests are still okay, because you select by term title.
• Feature: BoolTerms now expose the labels for the true and false values to the class. This makes it a matter of doing trivial sub-classing to change the labels for boolean terms.
• Feature: Exposed several attributes of the widget manager to the form for convenience. The attributes are: mode, ignoreContext, ignoreRequest, ignoreReadonly.
• Feature: Provide more user-friendly error messages for number formatting.
• Refactoring: The widget specific class name was in camel-case. A converntion that later developed uses always dash-based naming of HTML/CSS related variables. So for example, the class name "textWidget" is now "text-widget". This change will most likely require some changes to your CSS declarations!
• Documentation: The text of field.txt has been reviewed linguistically.
• Documentation: While reviewing the form.txt with some people, several unclear and incomplete statements were discovered and fixed.
• Bug (IE): In Internet Explorer, when a label for a radio input field is only placed around the text describing the choice, then only the text is surrounded by a dashed box. IE users reported this to be confusing, thus we now place the label around the text and the input element so that both are surrounded by the dashed border. In Firefox and KHTML (Safari) only the radio button is surrounded all the time.
• Bug: When extracting and validating data in the widget manager, invariant errors were not converted to error view snippets.
• Bug: When error view snippets were not widget-specific -- in other words, the widget attribute was None -- rendering the template would fail.

1.5.0 (2007-07-18)

• Feature: Added a span around values for widgets in display mode. This allows for easier identification widget values in display mode.
• Feature: Added the concept of widget events and implemented a particular "after widget update" event that is called right after a widget is updated.
• Feature: Restructured the approach to customize button actions, by requiring the adapter to provide a new interface IButtonAction. Also, an adapter is now provided by default, still allowing cusotmization using the usual methods though.
• Feature: Added button widget. While it is not very useful without Javascript, it still belongs into this package for completion.
• Feature: All IFieldWidget instances that are also HTML element widgets now declare an additional CSS class of the form "<fieldtype.lower()>-field".
• Feature: Added addClass() method to HTML element widgets, so that adding a new CSS class is simpler.
• Feature: Renamed "css" attribute of the widget to "klass", because the class of an HTML element is a classification, not a CSS marker.
• Feature: Reviewed all widget attributes. Added all available HTML attributes to the widgets.
• Documentation: Removed mentioning of widget's "hint" attribute, since it does not exist.
• Optimization: The terms for a sequence widget were looked up multiple times among different components. The widget is now the canonical source for the terms and other components, such as the converter uses them. This avoids looking up the terms multiple times, which can be an expensive process for some applications.
• Bug/Feature: Correctly create labels for radio button choices.
• Bug: Buttons did not honor the name given by the schema, if created within one, because we were too anxious to give buttons a name. Now name assignment is delayed until the button is added to the button manager.
• Bug: Button actions were never updated in the actions manager.
• Bug: Added tests for textarea widget.

1.4.0 (2007-06-29)

• Feature: The select widget grew a new prompt flag, which allows you to explicitely request a selection prompt as the first option in the selection (even for required fields). When set, the prompt message is shown. Such a prompt as option is common in Web-UIs.
• Feature: Allow "no value message" of select widgets to be dynamically changed using an attribute value adapter.
• Feature: Internationalized data conversion for date, time, date/time, integer, float and decimal. Now the locale data is used to format and parse those data types to provide the bridge to text-based widgets. While those features require the latest zope.i18n package, backward compatibility is provided.
• Feature: All forms now have an optional label that can be used by the UI.
• Feature: Implemented groups within forms. Groups allow you to combine a set of fields/widgets into a logical unit. They were designed with ease of use in mind.
• Feature: Button Actions -- in other words, the widget for the button field -- can now be specified either as the "actionFactory" on the button field or as an adapter.
• Bug: Recorded all public select-widget attributes in the interface.

1.3.0 (2007-06-22)

• Feature: In an edit form applying the data and generating all necessary messages was all done within the "Apply" button handler. Now the actual task of storing is factored out into a new method called "applyChanges(data)", which returns whether the data has been changed. This is useful for forms not dealing with objects.
• Feature: Added support for hidden fields. You can now use the hidden mode for widgets which should get rendered as <input type="hidden">. Note: Make sure you use the new formui templates which will avoid rendering
  labels for hidden widgets or adjust your custom form macros.
• Feature: Added missing_value support to data/time converters
• Feature: Added named vocabulary lookup in ChoiceTerms and CollectionTerms.
• Feature: Implemented support for FileUpload in FileWidget.

  • Added helper for handling FileUpload widgets:

    • extractContentType(form, id)

      Extracts the content type if IBytes/IFileWidget was used.

    • extractFileName(form, id, cleanup=True, allowEmtpyPostFix=False)

      Extracts a filename if IBytes/IFileWidget was used.

      Uploads from win/IE need some cleanup because the filename includes also the path. The option cleanup=True will do this for you. The option allowEmtpyPostFix allows you to pass a filename without extensions. By default this option is set to False and will raise a ValueError if a filename doesn't contain an extension.

  • Created afile upload data converter registered for IBytes/IFileWidget ensuring that the converter will only be used for fiel widgets. The file widget is now the default for the bytes field. If you need to use a text area widget for IBytes, you have to register a custom widget in the form using:

    fields['foobar'].widgetFactory = TextWidget
    

• Feature: Originally, when an attribute access failed in Unauthorized or ForbiddenAttribute exceptions, they were ignored as if the attribute would have no value. Now those errors are propagated and the system will fail providing the developer with more feedback. The datamanager also grew a new query() method that returns always a default and the get() method propagates any exceptions.
• Feature: When writing to a field is forbidden due to insufficient priviledges, the resulting widget mode will be set to "display". This behavior can be overridden by explicitely specifying the mode on a field.
• Feature: Added an add form implementation against IAdding. While this is not an encouraged method of adding components, many people still use this API to extend the ZMI.
• Feature: The IFields class' select() and omit() method now support two ketword arguments "prefix" and "interface" that allow the selection and omission of prefixed fields and still specify the short name. Thanks to Nikolay Kim for the idea.
• Feature: HTML element ids containing dots are not very good, because then the "element#id" CSS selector does not work and at least in Firefox the attribute selector ("element[attr=value]") does not work for the id either. Converted the codebase to use dashes in ids instead.
• Bug/Feature: The IWidgets component is now an adapter of the form content and not the form context. This guarantees that vocabulary factories receive a context that is actually useful.
• Bug: The readonly flag within a field was never honored. When a field is readonly, it is displayed in "display" mode now. This can be overridden by the widget manager's "ignoreReadonly" flag, which is necessary for add forms.
• Bug: The mode selection made during the field layout creation was not honored and the widget manager always overrode the options providing its value. Now the mode specified in the field is more important than the one from the widget manager.
• Bug: It sometimes happens that the sequence widget has the no-value token as one element. This caused displayValue() to fail, since it tried to find a term for it. For now we simply ignore the no-value token.
• Bug: Fixed the converter when the incoming value is an empty string. An empty string really means that we have no value and it is thus missing, returning the missing value.
• Bug: Fix a slightly incorrect implementation. It did not cause any harm in real-world forms, but made unit testing much harder, since an API expectation was not met correctly.
• Bug: When required selections where not selected in radio and checkbox widgets, then the conversion did not behave correctly. This also revealed some issues with the converter code that have been fixed now.
• Bug: When fields only had a vocabulary name, the choice terms adaptation would fail, since the field was not bound. This has now been corrected.
• Documentation: Integrated English language and content review improvements by Roy Mathew in form.txt.

1.2.0 (2007-05-30)

• Feature: Added ability to change the button action title using an IValue adapter.

1.1.0 (2007-05-30)

• Feature: Added compatibility for Zope 3.3 and thus Zope 2.10.

1.0.0 (2007-05-24)

• Initial Release