Validation api

demo/radio-group-demos.html

@@ -20,11 +20,12 @@ <h3>Radio Group</h3>
     <h3>Radio Group Disabled</h3>
     <vaadin-demo-snippet id="radio-group-demos-radio-group-disabled">
       <template preserve-content>
-        <vaadin-radio-group disabled>
+        <vaadin-radio-group label="Mark" disabled>
           <vaadin-radio-button>1</vaadin-radio-button>
           <vaadin-radio-button>2</vaadin-radio-button>
           <vaadin-radio-button>3</vaadin-radio-button>
           <vaadin-radio-button>4</vaadin-radio-button>
+          <vaadin-radio-button>5</vaadin-radio-button>
         </vaadin-radio-group>
       </template>
     </vaadin-demo-snippet>
@@ -45,16 +46,16 @@ <h3>Radio Group with Value</h3>
       </template>
     </vaadin-demo-snippet>
 
-    <h3>Radio Group with Iron Form</h3>
+    <h3>Radio Group with Validation in Iron Form</h3>
     <vaadin-demo-snippet id="radio-group-demos-radio-group-with-iron-form">
       <template preserve-content>
         <iron-form id="test-form">
           <form>
-            <vaadin-radio-group>
-              <vaadin-radio-button name="radio-group-first">1</vaadin-radio-button>
-              <vaadin-radio-button name="radio-group-second">2</vaadin-radio-button>
-              <vaadin-radio-button name="radio-group-third">3</vaadin-radio-button>
-              <vaadin-radio-button name="radio-group-fourth">4</vaadin-radio-button>
+            <vaadin-radio-group label="Complexity Level" required error-message="Please select an option">
+              <vaadin-radio-button name="complexity-one">1</vaadin-radio-button>
+              <vaadin-radio-button name="complexity-two">2</vaadin-radio-button>
+              <vaadin-radio-button name="complexity-three">3</vaadin-radio-button>
+              <vaadin-radio-button name="complexity-four">4</vaadin-radio-button>
             </vaadin-radio-group>
             <vaadin-button id="submit-button">Submit</vaadin-button>
           </form>
@@ -77,16 +78,16 @@ <h3>Radio Group with Iron Form</h3>
       </template>
     </vaadin-demo-snippet>
 
-    <h3>Radio Group with Iron Form with custom value</h3>
+    <h3>Radio Group with Custom Value Name in Iron Form</h3>
     <vaadin-demo-snippet id="radio-group-demos-radio-group-with-iron-form-with-custom-value">
       <template preserve-content>
         <iron-form id="test-form-custom-value">
           <form>
-            <vaadin-radio-group>
-              <vaadin-radio-button name="radio-group" value="first">1</vaadin-radio-button>
-              <vaadin-radio-button name="radio-group" value="second">2</vaadin-radio-button>
-              <vaadin-radio-button name="radio-group" value="third">3</vaadin-radio-button>
-              <vaadin-radio-button name="radio-group" value="fourth">4</vaadin-radio-button>
+            <vaadin-radio-group label="Complexity Level" required error-message="Please select an option">
+              <vaadin-radio-button name="complexity" value="1">1</vaadin-radio-button>
+              <vaadin-radio-button name="complexity" value="2">2</vaadin-radio-button>
+              <vaadin-radio-button name="complexity" value="3">3</vaadin-radio-button>
+              <vaadin-radio-button name="complexity" value="4">4</vaadin-radio-button>
             </vaadin-radio-group>
             <vaadin-button id="submit-button-custom-value">Submit</vaadin-button>
           </form>

src/vaadin-radio-group.html

@@ -43,8 +43,12 @@
         <slot id="slot"></slot>
       </div>
 
+      <div part="error-message"
+        id="[[_errorId]]"
+        aria-live="assertive"
+        aria-hidden$="[[_getErrorMessageAriaHidden(invalid, errorMessage, _errorId)]]"
+      >[[errorMessage]]</div>
     </div>
-
   </template>
 
   <script>
@@ -73,7 +77,9 @@
        *
        * Attribute  | Description | Part name
        * -----------|-------------|------------
-       * `disabled` | Set when the radio group and its children are disabled. | :host
+       * `disabled`   | Set when the radio group and its children are disabled. | :host
+       * `readonly` | Set to a readonly text field | :host
+       * `invalid` | Set when the element is invalid | :host
        * `has-label` | Set when the element has a label | :host
        *
        * See [ThemableMixin – how to apply styles for shadow parts](https://github.com/vaadin/vaadin-themable-mixin/wiki)
@@ -99,6 +105,45 @@
               observer: '_disabledChanged'
             },
 
+            /**
+             * This attribute indicates that the user cannot modify the value of the control.
+             */
+            readonly: {
+              type: Boolean,
+              reflectToAttribute: true,
+              observer: '_readonlyChanged'
+            },
+
+            /**
+             * This property is set to true when the value is invalid.
+             */
+            invalid: {
+              type: Boolean,
+              reflectToAttribute: true,
+              notify: true,
+              value: false
+            },
+
+            /**
+             * Specifies that the user must fill in a value.
+             */
+            required: {
+              type: Boolean,
+              reflectToAttribute: true
+            },
+
+            /**
+             * Error to show when the input value is invalid.
+             */
+            errorMessage: {
+              type: String,
+              value: ''
+            },
+
+            _errorId: {
+              type: String
+            },
+
             _checkedButton: {
               type: Object,
               observer: '_checkedButtonChanged'
@@ -160,6 +205,11 @@
           }
 
           this.setAttribute('role', 'radiogroup');
+
+          this.addEventListener('focusout', e => this.validate());
+
+          const uniqueId = RadioGroupElement._uniqueId = 1 + RadioGroupElement._uniqueId || 0;
+          this._errorId = `${this.constructor.is}-error-${uniqueId}`;
         }
 
         get _radioButtons() {
@@ -173,17 +223,31 @@
 
         _disabledChanged(disabled) {
           this.setAttribute('aria-disabled', disabled);
+          this._updateDisableButtons();
+        }
+
+        _updateDisableButtons() {
+          this._radioButtons.forEach(button => {
+            if (this.disabled) {
+              button.disabled = true;
+            } else if (this.readonly) {
+              // it's not possible to set readonly to radio buttons, but we can
+              // unchecked ones instead.
+              button.disabled = button !== this._checkedButton && this.readonly;
+            } else {
+              button.disabled = false;
+            }
+          });
+        }
 
-          this._radioButtons.forEach(button => button.disabled = disabled);
+        _readonlyChanged(newV, oldV) {
+          (newV || oldV) && this._updateDisableButtons();
         }
 
         _addActiveListeners() {
           this.addEventListener('keydown', e => {
             // if e.target is vaadin-radio-group then assign to checkedRadioButton currently checked radio button
             var checkedRadioButton = (e.target == this) ? this._checkedButton : e.target;
-            if (this.disabled) {
-              return;
-            }
 
             // LEFT, UP - select previous radio button
             if (e.keyCode === 37 || e.keyCode === 38) {
@@ -216,6 +280,7 @@
           return this.contains(activeElement);
         }
 
+
         _hasEnabledButtons() {
           return !this._radioButtons.every((button) => button.disabled);
         }
@@ -250,14 +315,14 @@
 
         _changeSelectedButton(button) {
           this._checkedButton = button;
-
+          this.readonly && this._updateDisableButtons();
           this._setFocusable(this._radioButtons.indexOf(button));
         }
 
         _checkedButtonChanged(checkedButton) {
           this._radioButtons.forEach(button => button.checked = button === checkedButton);
-
           this.value = checkedButton.value;
+          this.validate();
         }
 
         _valueChanged(newV, oldV) {
@@ -270,6 +335,30 @@
               console.warn(`No <vaadin-radio-button> with value ${newV} found.`);
             }
           }
+
+          if (newV !== '' && newV != null) {
+            this.setAttribute('has-value', '');
+          } else {
+            this.removeAttribute('has-value');
+          }
+        }
+
+        /**
+         * Returns true if `value` is valid.
+         * `<iron-form>` uses this to check the validity or all its elements.
+         *
+         * @return {boolean} True if the value is valid.
+         */
+        validate() {
+          return !(this.invalid = !this.checkValidity());
+        }
+
+        /**
+         * Returns true if the current input value satisfies all constraints (if any)
+         * @returns {boolean}
+         */
+        checkValidity() {
+          return !this.required || !!this.value;
         }
 
         _setFocusable(idx) {
@@ -285,6 +374,13 @@
           }
         }
 
+        _getActiveErrorId(invalid, errorMessage, errorId) {
+          return errorMessage && invalid ? errorId : undefined;
+        }
+
+        _getErrorMessageAriaHidden(invalid, errorMessage, errorId) {
+          return (!this._getActiveErrorId(invalid, errorMessage, errorId)).toString();
+        }
       }
 
       customElements.define(RadioGroupElement.is, RadioGroupElement);

test/vaadin-radio-group.html

@@ -35,12 +35,23 @@
 
   <script>
     describe('vaadin-radio-group', () => {
-      var vaadinRadioButtonGroup, vaadinRadioButtonList,
+
+      function blur(e) {
+        e.dispatchEvent(new CustomEvent('focusout', {bubbles: true, composed: true}));
+      }
+
+      function visible(e) {
+        const rect = e.getBoundingClientRect();
+        return !!(rect.width && rect.height);
+      }
+
+      var vaadinRadioButtonGroup, vaadinRadioButtonList, errorElement,
         buttonsListWithDisabled, groupWithDisabledButton;
 
       beforeEach(() => {
         vaadinRadioButtonGroup = fixture('default');
         vaadinRadioButtonList = vaadinRadioButtonGroup.querySelectorAll('vaadin-radio-button');
+        errorElement = vaadinRadioButtonGroup.shadowRoot.querySelector('[part="error-message"]');
 
         groupWithDisabledButton = fixture('with-disabled-button');
         buttonsListWithDisabled = groupWithDisabledButton.querySelectorAll('vaadin-radio-button');
@@ -107,6 +118,29 @@
         expect(vaadinRadioButtonList[2].checked).to.be.false;
       });
 
+      it('should check radio button with keyboard if not disabled or readonly', () => {
+        vaadinRadioButtonList[1].checked = true;
+
+        MockInteractions.keyDownOn(vaadinRadioButtonGroup, 39);
+        expect(vaadinRadioButtonList[2].checked).to.be.true;
+      });
+
+      it('should not check radio button with keyboard if disabled', () => {
+        vaadinRadioButtonList[1].checked = true;
+        vaadinRadioButtonGroup.disabled = true;
+
+        MockInteractions.keyDownOn(vaadinRadioButtonGroup, 39);
+        expect(vaadinRadioButtonList[2].checked).to.be.false;
+      });
+
+      it('should not check radio button with keyboard if readonly', () => {
+        vaadinRadioButtonList[1].checked = true;
+        vaadinRadioButtonGroup.readonly = true;
+
+        MockInteractions.keyDownOn(vaadinRadioButtonGroup, 39);
+        expect(vaadinRadioButtonList[2].checked).to.be.false;
+      });
+
       it('previous/last radio button should be focused and checked after left/up', () => {
         vaadinRadioButtonList[1].checked = true;
 
@@ -215,6 +249,94 @@
         expect(vaadinRadioButtonGroup.label).to.be.equal('foo');
       });
 
+      it('should disable unchecked buttons when readonly', () => {
+        vaadinRadioButtonGroup.readonly = true;
+        expect(vaadinRadioButtonList[0].disabled).to.be.true;
+        expect(vaadinRadioButtonList[1].disabled).to.be.true;
+        expect(vaadinRadioButtonList[2].disabled).to.be.true;
+
+        vaadinRadioButtonGroup.value = '2';
+        expect(vaadinRadioButtonList[0].disabled).to.be.true;
+        expect(vaadinRadioButtonList[1].disabled).to.be.false;
+        expect(vaadinRadioButtonList[2].disabled).to.be.true;
+
+        vaadinRadioButtonGroup.readonly = false;
+        expect(vaadinRadioButtonList[0].disabled).to.be.false;
+        expect(vaadinRadioButtonList[1].disabled).to.be.false;
+        expect(vaadinRadioButtonList[2].disabled).to.be.false;
+      });
+
+      it('should not have the has-value attribute by default', () => {
+        expect(vaadinRadioButtonGroup.hasAttribute('has-value')).to.be.false;
+      });
+
+      it('should change the has-value attribute on value', () => {
+        vaadinRadioButtonGroup.value = '2';
+        expect(vaadinRadioButtonGroup.hasAttribute('has-value')).to.be.true;
+
+        vaadinRadioButtonGroup.value = '';
+        expect(vaadinRadioButtonGroup.hasAttribute('has-value')).to.be.false;
+      });
+
+      it('should pass validation when field is not required', () => {
+        expect(vaadinRadioButtonGroup.checkValidity()).to.be.true;
+        expect(vaadinRadioButtonGroup.invalid).to.be.false;
+      });
+
+      it('should not set invalid when field is required and user has not blurred yet', () => {
+        vaadinRadioButtonGroup.required = true;
+        expect(vaadinRadioButtonGroup.checkValidity()).to.be.false;
+        expect(vaadinRadioButtonGroup.invalid).to.be.false;
+      });
+
+      it('validate method should set invalid', () => {
+        vaadinRadioButtonGroup.required = true;
+        vaadinRadioButtonGroup.validate();
+        expect(vaadinRadioButtonGroup.invalid).to.be.true;
+      });
+
+      it('should validate after changing selected option', () => {
+        vaadinRadioButtonGroup.required = true;
+        vaadinRadioButtonGroup.validate();
+
+        vaadinRadioButtonList[1].checked = true;
+        expect(vaadinRadioButtonGroup.invalid).to.be.false;
+      });
+
+      it('should pass validation and set invalid when field is required and user blurs', () => {
+        vaadinRadioButtonGroup.required = true;
+        blur(vaadinRadioButtonGroup);
+        expect(vaadinRadioButtonGroup.checkValidity()).to.be.false;
+        expect(vaadinRadioButtonGroup.invalid).to.be.true;
+      });
+
+      it('error should have appropriate aria attributes and id', () => {
+        expect(errorElement.getAttribute('aria-live')).to.be.equal('assertive');
+        expect(errorElement.getAttribute('aria-hidden')).to.be.equal('true');
+        expect(/^vaadin-radio-group-error-\d+$/.test(errorElement.id)).to.be.true;
+      });
+
+      it('should remove aria-hidden when error is shown', () => {
+        vaadinRadioButtonGroup.errorMessage = 'Bad input!';
+        vaadinRadioButtonGroup.invalid = true;
+        expect(errorElement.getAttribute('aria-hidden')).to.be.equal('false');
+      });
+
+      it('should hide error message by default', () => {
+        vaadinRadioButtonGroup.errorMessage = 'Bad input!';
+        expect(visible(errorElement)).to.be.false;
+      });
+
+      it('should show error message on invalid', done => {
+        vaadinRadioButtonGroup.required = true;
+        vaadinRadioButtonGroup.errorMessage = 'Bad input!';
+        blur(vaadinRadioButtonGroup);
+
+        Polymer.Base.async(() => {
+          expect(visible(errorElement)).to.be.true;
+          done();
+        }, 100);
+      });
     });
   </script>
 </body>