CheckBoxWidget

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 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>
<input name="widget.name-empty-marker" type="hidden" value="1" />

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 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>
<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 = '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><span class="option">
  <input type="hidden" id="widget-id-1" name="widget.name:list"
         class="checkbox-widget" value="false" />
</span>

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">
  <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" />

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">
  <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">
  <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 = 'true'
>>> 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>