Add "None of these" and "or" divider to checkboxes

src/govuk/components/checkboxes/_index.scss

@@ -138,6 +138,19 @@
     opacity: .5;
   }
 
+  // =========================================================
+  // Dividers ('or')
+  // =========================================================
+
+  .govuk-checkboxes__divider {
+    $govuk-divider-size: $govuk-checkboxes-size !default;
+    @include govuk-font($size: 19);
+    @include govuk-text-colour;
+    width: $govuk-divider-size;
+    margin-bottom: govuk-spacing(2);
+    text-align: center;
+  }
+
   // =========================================================
   // Conditional reveals
   // =========================================================

src/govuk/components/checkboxes/checkboxes.js

@@ -86,6 +86,47 @@ Checkboxes.prototype.syncConditionalRevealWithInputState = function ($input) {
   }
 }
 
+/**
+ * Uncheck other checkboxes
+ *
+ * Find any other checkbox inputs with the same name value, and uncheck them.
+ * This is useful for when a “None of these" checkbox is checked.
+ */
+Checkboxes.prototype.unCheckAllInputsExcept = function ($input) {
+  var allInputsWithSameName = document.querySelectorAll('input[type="checkbox"][name="' + $input.name + '"]')
+
+  nodeListForEach(allInputsWithSameName, function ($inputWithSameName) {
+    var hasSameFormOwner = ($input.form === $inputWithSameName.form)
+    if (hasSameFormOwner && $inputWithSameName !== $input) {
+      $inputWithSameName.checked = false
+    }
+  })
+
+  this.syncAllConditionalReveals()
+}
+
+/**
+ * Uncheck exclusive inputs
+ *
+ * Find any checkbox inputs with the same name value and the 'exclusive' behaviour,
+ * and uncheck them. This helps prevent someone checking both a regular checkbox and a
+ * "None of these" checkbox in the same fieldset.
+ */
+Checkboxes.prototype.unCheckExclusiveInputs = function ($input) {
+  var allInputsWithSameNameAndExclusiveBehaviour = document.querySelectorAll(
+    'input[data-behaviour="exclusive"][type="checkbox"][name="' + $input.name + '"]'
+  )
+
+  nodeListForEach(allInputsWithSameNameAndExclusiveBehaviour, function ($exclusiveInput) {
+    var hasSameFormOwner = ($input.form === $exclusiveInput.form)
+    if (hasSameFormOwner) {
+      $exclusiveInput.checked = false
+    }
+  })
+
+  this.syncAllConditionalReveals()
+}
+
 /**
  * Click event handler
  *
@@ -97,12 +138,29 @@ Checkboxes.prototype.syncConditionalRevealWithInputState = function ($input) {
 Checkboxes.prototype.handleClick = function (event) {
   var $target = event.target
 
-  // If a checkbox with aria-controls, handle click
-  var isCheckbox = $target.getAttribute('type') === 'checkbox'
+  // Ignore clicks on things that aren't checkbox inputs
+  if ($target.type !== 'checkbox') {
+    return
+  }
+
+  // If the checkbox conditionally-reveals some content, sync the state
   var hasAriaControls = $target.getAttribute('aria-controls')
-  if (isCheckbox && hasAriaControls) {
+  if (hasAriaControls) {
     this.syncConditionalRevealWithInputState($target)
   }
+
+  // No further behaviour needed for unchecking
+  if (!$target.checked) {
+    return
+  }
+
+  // Handle 'exclusive' checkbox behaviour (ie "None of these")
+  var hasBehaviourExclusive = ($target.getAttribute('data-behaviour') === 'exclusive')
+  if (hasBehaviourExclusive) {
+    this.unCheckAllInputsExcept($target)
+  } else {
+    this.unCheckExclusiveInputs($target)
+  }
 }
 
 export default Checkboxes

src/govuk/components/checkboxes/checkboxes.test.js

@@ -121,3 +121,72 @@ describe('Checkboxes with conditional reveals', () => {
     })
   })
 })
+
+describe('Checkboxes with a None checkbox', () => {
+  describe('when JavaScript is available', () => {
+    it('unchecks other checkboxes when the None checkbox is checked', async () => {
+      await goToAndGetComponent('checkboxes', 'with-divider-and-None')
+
+      // Check the first 3 checkboxes
+      await page.click('#with-divider-and-none')
+      await page.click('#with-divider-and-none-2')
+      await page.click('#with-divider-and-none-3')
+
+      // Check the None checkbox
+      await page.click('#with-divider-and-none-5')
+
+      // Expect first 3 checkboxes to have been unchecked
+      const firstCheckboxIsUnchecked = await waitForVisibleSelector('[id="with-divider-and-none"]:not(:checked)')
+      expect(firstCheckboxIsUnchecked).toBeTruthy()
+
+      const secondCheckboxIsUnchecked = await waitForVisibleSelector('[id="with-divider-and-none-2"]:not(:checked)')
+      expect(secondCheckboxIsUnchecked).toBeTruthy()
+
+      const thirdCheckboxIsUnchecked = await waitForVisibleSelector('[id="with-divider-and-none-3"]:not(:checked)')
+      expect(thirdCheckboxIsUnchecked).toBeTruthy()
+    })
+
+    it('unchecks the None checkbox when any other checkbox is checked', async () => {
+      await goToAndGetComponent('checkboxes', 'with-divider-and-None')
+
+      // Check the None checkbox
+      await page.click('#with-divider-and-none-5')
+
+      // Check the first checkbox
+      await page.click('#with-divider-and-none')
+
+      // Expect the None checkbox to have been unchecked
+      const noneCheckboxIsUnchecked = await waitForVisibleSelector('[id="with-divider-and-none-5"]:not(:checked)')
+      expect(noneCheckboxIsUnchecked).toBeTruthy()
+    })
+  })
+})
+
+describe('Checkboxes with a None checkbox and conditional reveals', () => {
+  describe('when JavaScript is available', () => {
+    it('unchecks other checkboxes and hides conditional reveals when the None checkbox is checked', async () => {
+      const $ = await goToAndGetComponent('checkboxes', 'with-divider,-None-and-conditional-items')
+
+      // Check the 4th checkbox, which reveals an additional field
+      await page.click('#with-divider-and-none-and-conditional-items-4')
+
+      const $checkedInput = $('#with-divider-and-none-and-conditional-items-4')
+      const conditionalContentId = $checkedInput.attr('aria-controls')
+
+      // Expect conditional content to have been revealed
+      const isConditionalContentVisible = await waitForVisibleSelector(`[id="${conditionalContentId}"]`)
+      expect(isConditionalContentVisible).toBeTruthy()
+
+      // Check the None checkbox
+      await page.click('#with-divider-and-none-and-conditional-items-6')
+
+      // Expect the 4th checkbox to have been unchecked
+      const forthCheckboxIsUnchecked = await waitForVisibleSelector('[id="with-divider-and-none-and-conditional-items-4"]:not(:checked)')
+      expect(forthCheckboxIsUnchecked).toBeTruthy()
+
+      // Expect conditional content to have been hidden
+      const isConditionalContentHidden = await waitForHiddenSelector(`[id="${conditionalContentId}"]`)
+      expect(isConditionalContentHidden).toBeTruthy()
+    })
+  })
+})

src/govuk/components/checkboxes/checkboxes.yaml

@@ -70,6 +70,10 @@ params:
     required: false
     description: Provide hint to each checkbox item.
     isComponent: true
+  - name: divider
+    type: string
+    required: false
+    description: Divider text to separate checkbox items, for example the text "or".
   - name: checked
     type: boolean
     required: false
@@ -82,6 +86,10 @@ params:
     type: string
     required: false
     description: Provide content for the conditional reveal.
+  - name: behaviour
+    type: string
+    required: false
+    description: If set to `exclusive`, implements a "None of these" type behaviour via javascript when checkboxes are clicked
   - name: disabled
     type: boolean
     required: false
@@ -121,6 +129,52 @@ examples:
       - value: other
         text: Citizen of another country
 
+- name: with divider and None
+  data:
+    name: with-divider-and-none
+    fieldset:
+      legend:
+        text: Which types of waste do you transport regularly?
+        classes: govuk-fieldset__legend--l
+        isPageHeading: true
+    items:
+      - value: animal
+        text: Waste from animal carcasses
+      - value: mines
+        text: Waste from mines or quarries
+      - value: farm
+        text: Farm or agricultural waste
+      - divider: or
+      - value: none
+        text: None of these
+        behaviour: exclusive
+
+- name: with divider, None and conditional items
+  data:
+    name: with-divider-and-none-and-conditional-items
+    fieldset:
+      legend:
+        text: Do you have any access needs?
+        classes: govuk-fieldset__legend--l
+        isPageHeading: true
+    items:
+      - value: accessible-toilets
+        text: Accessible toilets available
+      - value: braille
+        text: Braille translation service available
+      - value: disabled-car-parking
+        text: Disabled car parking available
+      - value: another-access-need
+        text: Another access need
+        conditional:
+          html: |
+            <label class="govuk-label" for="other-access-needs">Other access needs</label>
+            <textarea class="govuk-textarea govuk-!-width-one-third" name="other-access-needs" id="other-access-needs"></textarea>
+      - divider: or
+      - value: none
+        text: None of these
+        behaviour: exclusive
+
 - name: with id and name
   data:
     name: with-id-and-name

src/govuk/components/checkboxes/template.njk

@@ -14,13 +14,6 @@
    {% set describedBy = params.fieldset.describedBy %}
 {% endif %}
 
-{% set isConditional = false %}
-{% for item in params.items %}
-  {% if item.conditional.html %}
-    {% set isConditional = true %}
-  {% endif %}
-{% endfor %}
-
 {#- fieldset is false by default -#}
 {% set hasFieldset = true if params.fieldset else false %}
 
@@ -51,7 +44,7 @@
 {% endif %}
   <div class="govuk-checkboxes {%- if params.classes %} {{ params.classes }}{% endif %}"
     {%- for attribute, value in params.attributes %} {{ attribute }}="{{ value }}"{% endfor %}
-    {%- if isConditional %} data-module="govuk-checkboxes"{% endif -%}>
+    data-module="govuk-checkboxes">
     {% for item in params.items %}
       {% if item %}
         {#- If the user explicitly sets an id, use this instead of the regular idPrefix -#}
@@ -67,38 +60,43 @@
         {%- endif -%}
         {% set name = item.name if item.name else params.name %}
         {% set conditionalId = "conditional-" + id %}
-        {% set hasHint = true if item.hint.text or item.hint.html %}
-        {% set itemHintId = id + "-item-hint" if hasHint else "" %}
-        {% set itemDescribedBy = describedBy if not hasFieldset else "" %}
-        {% set itemDescribedBy = (itemDescribedBy + " " + itemHintId) | trim %}
-        <div class="govuk-checkboxes__item">
-          <input class="govuk-checkboxes__input" id="{{ id }}" name="{{ name }}" type="checkbox" value="{{ item.value }}"
-          {{-" checked" if item.checked }}
-          {{-" disabled" if item.disabled }}
-          {%- if item.conditional.html %} data-aria-controls="{{ conditionalId }}"{% endif -%}
-          {%- if itemDescribedBy %} aria-describedby="{{ itemDescribedBy }}"{% endif -%}
-          {%- for attribute, value in item.attributes %} {{ attribute }}="{{ value }}"{% endfor -%}>
-          {{ govukLabel({
-            html: item.html,
-            text: item.text,
-            classes: 'govuk-checkboxes__label' + (' ' + item.label.classes if item.label.classes),
-            attributes: item.label.attributes,
-            for: id
-          }) | indent(6) | trim }}
-          {% if hasHint %}
-          {{ govukHint({
-            id: itemHintId,
-            classes: 'govuk-checkboxes__hint' + (' ' + item.hint.classes if item.hint.classes),
-            attributes: item.hint.attributes,
-            html: item.hint.html,
-            text: item.hint.text
-          }) | indent(6) | trim }}
-          {% endif %}
-        </div>
-        {% if item.conditional.html %}
-          <div class="govuk-checkboxes__conditional{% if not item.checked %} govuk-checkboxes__conditional--hidden{% endif %}" id="{{ conditionalId }}">
-            {{ item.conditional.html | safe }}
+        {%- if item.divider %}
+          <div class="govuk-checkboxes__divider">{{ item.divider }}</div>
+        {%- else %}
+          {% set hasHint = true if item.hint.text or item.hint.html %}
+          {% set itemHintId = id + "-item-hint" if hasHint else "" %}
+          {% set itemDescribedBy = describedBy if not hasFieldset else "" %}
+          {% set itemDescribedBy = (itemDescribedBy + " " + itemHintId) | trim %}
+          <div class="govuk-checkboxes__item">
+            <input class="govuk-checkboxes__input" id="{{ id }}" name="{{ name }}" type="checkbox" value="{{ item.value }}"
+            {{-" checked" if item.checked }}
+            {{-" disabled" if item.disabled }}
+            {%- if item.conditional.html %} data-aria-controls="{{ conditionalId }}"{% endif -%}
+            {%- if item.behaviour %} data-behaviour="{{ item.behaviour }}"{% endif -%}
+            {%- if itemDescribedBy %} aria-describedby="{{ itemDescribedBy }}"{% endif -%}
+            {%- for attribute, value in item.attributes %} {{ attribute }}="{{ value }}"{% endfor -%}>
+            {{ govukLabel({
+              html: item.html,
+              text: item.text,
+              classes: 'govuk-checkboxes__label' + (' ' + item.label.classes if item.label.classes),
+              attributes: item.label.attributes,
+              for: id
+            }) | indent(6) | trim }}
+            {% if hasHint %}
+            {{ govukHint({
+              id: itemHintId,
+              classes: 'govuk-checkboxes__hint' + (' ' + item.hint.classes if item.hint.classes),
+              attributes: item.hint.attributes,
+              html: item.hint.html,
+              text: item.hint.text
+            }) | indent(6) | trim }}
+            {% endif %}
           </div>
+          {% if item.conditional.html %}
+            <div class="govuk-checkboxes__conditional{% if not item.checked %} govuk-checkboxes__conditional--hidden{% endif %}" id="{{ conditionalId }}">
+              {{ item.conditional.html | safe }}
+            </div>
+          {% endif %}
         {% endif %}
       {% endif %}
     {% endfor %}

src/govuk/components/checkboxes/template.test.js

@@ -47,6 +47,21 @@ describe('Checkboxes', () => {
     expect($items.length).toEqual(2)
   })
 
+  it('render example with a divider and ‘None’ checkbox with exclusive behaviour', () => {
+    const $ = render('checkboxes', examples['with divider and None'])
+
+    const $component = $('.govuk-checkboxes')
+
+    const $divider = $component.find('.govuk-checkboxes__divider').first()
+    expect($divider.text().trim()).toEqual('or')
+
+    const $items = $component.find('.govuk-checkboxes__item')
+    expect($items.length).toEqual(4)
+
+    const $orItemInput = $items.last().find('input').first()
+    expect($orItemInput.attr('data-behaviour')).toEqual('exclusive')
+  })
+
   it('render additional label classes', () => {
     const $ = render('checkboxes', examples['with label classes'])