Checkbox Widget¶
Note: the checkbox widget isn’t registered for a field by default. You can use
the widgetFactory
argument of a IField
object if you construct fields
or set the custom widget factory on selected fields later.
The CheckBoxWidget
widget renders a checkbox input type field e.g. <input
type=”checkbox” />
>>> from zope.interface.verify import verifyClass
>>> from z3c.form import interfaces
>>> from z3c.form.browser import checkbox
The CheckboxWidget
is a widget:
>>> verifyClass(interfaces.IWidget, checkbox.CheckBoxWidget)
True
The widget can render a input field only by adapting a request:
>>> from z3c.form.testing import TestRequest
>>> request = TestRequest()
>>> widget = checkbox.CheckBoxWidget(request)
Set a name and id for the widget:
>>> widget.id = 'widget-id'
>>> widget.name = 'widget.name'
Such a field provides IWidget:
>>> interfaces.IWidget.providedBy(widget)
True
We also need to register the template for at least the widget and request:
>>> import os.path
>>> import zope.interface
>>> from zope.publisher.interfaces.browser import IDefaultBrowserLayer
>>> from zope.pagetemplate.interfaces import IPageTemplate
>>> import z3c.form.browser
>>> import z3c.form.widget
>>> template = os.path.join(os.path.dirname(z3c.form.browser.__file__),
... 'checkbox_input.pt')
>>> factory = z3c.form.widget.WidgetTemplateFactory(template)
>>> zope.component.provideAdapter(factory,
... (zope.interface.Interface, IDefaultBrowserLayer, None, None, None),
... IPageTemplate, name='input')
If we render the widget we only get the empty marker:
>>> print(widget.render())
<input name="widget.name-empty-marker" type="hidden" value="1" />
Let’s provide some values for this widget. We can do this by defining
a vocabulary providing ITerms
. This vocabulary uses descriminators
wich will fit for our setup.
>>> import zope.schema.interfaces
>>> from zope.schema.vocabulary import SimpleVocabulary
>>> import z3c.form.term
>>> class MyTerms(z3c.form.term.ChoiceTermsVocabulary):
... def __init__(self, context, request, form, field, widget):
... self.terms = SimpleVocabulary.fromValues(['yes', 'no'])
>>> zope.component.provideAdapter(z3c.form.term.BoolTerms,
... adapts=(zope.interface.Interface,
... interfaces.IFormLayer, zope.interface.Interface,
... zope.interface.Interface, interfaces.ICheckBoxWidget))
Now let’s try if we get widget values:
>>> widget.update()
>>> print(widget.render())
<span id="widget-id">
<span class="option">
<input type="checkbox" id="widget-id-0" name="widget.name:list"
class="checkbox-widget" value="true" />
<label for="widget-id-0">
<span class="label">yes</span>
</label>
</span><span class="option">
<input type="checkbox" id="widget-id-1" name="widget.name:list"
class="checkbox-widget" value="false" />
<label for="widget-id-1">
<span class="label">no</span>
</label>
</span>
</span>
<input name="widget.name-empty-marker" type="hidden" value="1" />
- The checkbox json_data representation:
>>> from pprint import pprint >>> pprint(widget.json_data()) {'error': '', 'id': 'widget-id', 'label': '', 'mode': 'input', 'name': 'widget.name', 'options': [{'checked': False, 'id': 'widget-id-0', 'label': 'yes', 'name': 'widget.name:list', 'value': 'true'}, {'checked': False, 'id': 'widget-id-1', 'label': 'no', 'name': 'widget.name:list', 'value': 'false'}], 'required': False, 'type': 'check', 'value': ()}
If we set the value for the widget to yes
, we can se that the checkbox
field get rendered with a checked flag:
>>> widget.value = 'true'
>>> widget.update()
>>> print(widget.render())
<span id="widget-id">
<span class="option">
<input type="checkbox" id="widget-id-0" name="widget.name:list"
class="checkbox-widget" value="true"
checked="checked" />
<label for="widget-id-0">
<span class="label">yes</span>
</label>
</span><span class="option">
<input type="checkbox" id="widget-id-1" name="widget.name:list"
class="checkbox-widget" value="false" />
<label for="widget-id-1">
<span class="label">no</span>
</label>
</span>
</span>
<input name="widget.name-empty-marker" type="hidden" value="1" />
- The checkbox json_data representation:
>>> from pprint import pprint >>> pprint(widget.json_data()) {'error': '', 'id': 'widget-id', 'label': '', 'mode': 'input', 'name': 'widget.name', 'options': [{'checked': True, 'id': 'widget-id-0', 'label': 'yes', 'name': 'widget.name:list', 'value': 'true'}, {'checked': False, 'id': 'widget-id-1', 'label': 'no', 'name': 'widget.name:list', 'value': 'false'}], 'required': False, 'type': 'check', 'value': 'true'}
Check HIDDEN_MODE:
>>> template = os.path.join(os.path.dirname(z3c.form.browser.__file__),
... 'checkbox_hidden.pt')
>>> factory = z3c.form.widget.WidgetTemplateFactory(template)
>>> zope.component.provideAdapter(factory,
... (zope.interface.Interface, IDefaultBrowserLayer, None, None, None),
... IPageTemplate, name='hidden')
>>> widget.value = 'true'
>>> widget.mode = interfaces.HIDDEN_MODE
>>> print(widget.render())
<span class="option">
<input type="hidden" id="widget-id-0" name="widget.name:list"
class="checkbox-widget" value="true" />
</span>
<input name="widget.name-empty-marker" type="hidden" value="1" />
- The checkbox json_data representation:
>>> from pprint import pprint >>> pprint(widget.json_data()) {'error': '', 'id': 'widget-id', 'label': '', 'mode': 'hidden', 'name': 'widget.name', 'options': [{'checked': True, 'id': 'widget-id-0', 'label': 'yes', 'name': 'widget.name:list', 'value': 'true'}, {'checked': False, 'id': 'widget-id-1', 'label': 'no', 'name': 'widget.name:list', 'value': 'false'}], 'required': False, 'type': 'check', 'value': 'true'}
Make sure that we produce a proper label when we have no title for a term and the value (which is used as a backup label) contains non-ASCII characters:
>>> terms = SimpleVocabulary.fromValues([b'yes\012', b'no\243'])
>>> widget.terms = terms
>>> widget.update()
>>> pprint(list(widget.items))
[{'checked': False,
'id': 'widget-id-0',
'label': 'yes\n',
'name': 'widget.name:list',
'value': 'yes\n'},
{'checked': False,
'id': 'widget-id-1',
'label': 'no',
'name': 'widget.name:list',
'value': 'no...'}]
Note: The “234” character is interpreted differently in Pytohn 2 and 3 here. (This is mostly due to changes int he SimpleVocabulary code.)
Single Checkbox Widget¶
Instead of using the checkbox widget as an UI component to allow multiple selection from a list of choices, it can be also used by itself to toggle a selection, effectively making it a binary selector. So in this case it lends itself well as a boolean UI input component.
The SingleCheckboxWidget
is a widget:
>>> verifyClass(interfaces.IWidget, checkbox.SingleCheckBoxWidget)
True
The widget can render a input field only by adapting a request:
>>> request = TestRequest()
>>> widget = checkbox.SingleCheckBoxWidget(request)
Set a name and id for the widget:
>>> widget.id = 'widget-id'
>>> widget.name = 'widget.name'
Such a widget provides the IWidget
interface:
>>> interfaces.IWidget.providedBy(widget)
True
For there to be a sensible output, we need to give the widget a label:
>>> widget.label = u'Do you want that?'
>>> widget.update()
>>> print(widget.render())
<span class="option" id="widget-id">
<input type="checkbox" id="widget-id-0"
name="widget.name:list"
class="single-checkbox-widget" value="selected" />
<label for="widget-id-0">
<span class="label">Do you want that?</span>
</label>
</span>
<input name="widget.name-empty-marker" type="hidden"
value="1" />
- The checkbox json_data representation:
>>> from pprint import pprint >>> pprint(widget.json_data()) {'error': '', 'id': 'widget-id', 'label': 'Do you want that?', 'mode': 'input', 'name': 'widget.name', 'options': [{'checked': False, 'id': 'widget-id-0', 'label': 'Do you want that?', 'name': 'widget.name:list', 'value': 'selected'}], 'required': False, 'type': 'check', 'value': ()}
Initially, the box is not checked. Changing the widget value to the selection value, …
>>> widget.value = ['selected']
will make the box checked:
>>> widget.update()
>>> print(widget.render())
<span class="option" id="widget-id">
<input type="checkbox" id="widget-id-0"
name="widget.name:list"
class="single-checkbox-widget" value="selected"
checked="checked" />
<label for="widget-id-0">
<span class="label">Do you want that?</span>
</label>
</span>
<input name="widget.name-empty-marker" type="hidden"
value="1" />
If you do not specify the label on the widget directly, it is taken from the field
>>> from zope.schema import Bool
>>> widget = checkbox.SingleCheckBoxWidget(request)
>>> widget.id = 'widget-id'
>>> widget.name = 'widget.name'
>>> widget.field = Bool(title=u"Do you REALLY want that?")
>>> widget.update()
>>> print(widget.render())
<span class="option" id="widget-id">
<input type="checkbox" id="widget-id-0"
name="widget.name:list"
class="single-checkbox-widget" value="selected" />
<label for="widget-id-0">
<span class="label">Do you REALLY want that?</span>
</label>
</span>
<input name="widget.name-empty-marker" type="hidden"
value="1" />
Check HIDDEN_MODE:
>>> template = os.path.join(os.path.dirname(z3c.form.browser.__file__),
... 'checkbox_hidden.pt')
>>> factory = z3c.form.widget.WidgetTemplateFactory(template)
>>> zope.component.provideAdapter(factory,
... (zope.interface.Interface, IDefaultBrowserLayer, None, None, None),
... IPageTemplate, name='hidden')
>>> widget.value = 'selected'
>>> widget.mode = interfaces.HIDDEN_MODE
>>> print(widget.render())
<span class="option">
<input type="hidden" id="widget-id-0"
name="widget.name:list"
class="single-checkbox-widget" value="selected" />
</span>
<input name="widget.name-empty-marker" type="hidden" value="1" />
Term with non ascii __str__¶
Check if a term which __str__ returns non ascii string does not crash the update method
>>> from zope.interface.verify import verifyClass
>>> from z3c.form import interfaces
>>> from z3c.form.browser import checkbox
>>> from z3c.form.testing import TestRequest
>>> request = TestRequest()
>>> widget = checkbox.CheckBoxWidget(request)
>>> widget.id = 'widget-id'
>>> widget.name = 'widget.name'
>>> import zope.schema.interfaces
>>> from zope.schema.vocabulary import SimpleVocabulary,SimpleTerm
>>> import z3c.form.term
>>> class ObjWithNonAscii__str__:
... def __str__(self):
... return 'héhé!'
>>> class MyTerms(z3c.form.term.ChoiceTermsVocabulary):
... def __init__(self, context, request, form, field, widget):
... self.terms = SimpleVocabulary([
... SimpleTerm(ObjWithNonAscii__str__(), 'one', 'One'),
... SimpleTerm(ObjWithNonAscii__str__(), 'two', 'Two'),
... ])
>>> zope.component.provideAdapter(MyTerms,
... adapts=(zope.interface.Interface,
... interfaces.IFormLayer, zope.interface.Interface,
... zope.interface.Interface, interfaces.ICheckBoxWidget))
>>> widget.update()
>>> print(widget.render())
<html>
<body>
<span id="widget-id">
<span class="option">
<input class="checkbox-widget" id="widget-id-0" name="widget.name:list" type="checkbox" value="one">
<label for="widget-id-0">
<span class="label">One</span>
</label>
</span>
<span class="option">
<input class="checkbox-widget" id="widget-id-1" name="widget.name:list" type="checkbox" value="two">
<label for="widget-id-1">
<span class="label">Two</span>
</label>
</span>
</span>
<input name="widget.name-empty-marker" type="hidden" value="1">
</body>
</html>