Resolve "Inline validation for user's name and username length"

4 files changed, 75 insertions, 37 deletions

diff --git a/app/assets/javascripts/emoji/no_emoji_validator.js b/app/assets/javascripts/emoji/no_emoji_validator.js
index 0fd4dd74953..384d62a133a 100644
--- a/app/assets/javascripts/emoji/no_emoji_validator.js
+++ b/app/assets/javascripts/emoji/no_emoji_validator.js
@@ -1,10 +1,11 @@
 import { __ } from '~/locale';
 import emojiRegex from 'emoji-regex';
+import InputValidator from '../validators/input_validator';
 
-const invalidInputClass = 'gl-field-error-outline';
-
-export default class NoEmojiValidator {
+export default class NoEmojiValidator extends InputValidator {
   constructor(opts = {}) {
+    super();
+
     const container = opts.container || '';
     this.noEmojiEmelents = document.querySelectorAll(`${container} .js-block-emoji`);
 
@@ -19,45 +20,14 @@ export default class NoEmojiValidator {
 
     const { value } = this.inputDomElement;
 
+    this.errorMessage = __('Invalid input, please avoid emojis');
+
     this.validatePattern(value);
     this.setValidationStateAndMessage();
   }
 
   validatePattern(value) {
     const pattern = emojiRegex();
-    this.hasEmojis = new RegExp(pattern).test(value);
-
-    if (this.hasEmojis) {
-      this.inputDomElement.setCustomValidity(__('Invalid input, please avoid emojis'));
-    } else {
-      this.inputDomElement.setCustomValidity('');
-    }
-  }
-
-  setValidationStateAndMessage() {
-    if (!this.inputDomElement.checkValidity()) {
-      this.setInvalidState();
-    } else {
-      this.clearFieldValidationState();
-    }
-  }
-
-  clearFieldValidationState() {
-    this.inputDomElement.classList.remove(invalidInputClass);
-    this.inputErrorMessage.classList.add('hide');
-  }
-
-  setInvalidState() {
-    this.inputDomElement.classList.add(invalidInputClass);
-    this.setErrorMessage();
-  }
-
-  setErrorMessage() {
-    if (this.hasEmojis) {
-      this.inputErrorMessage.innerHTML = this.inputDomElement.validationMessage;
-    } else {
-      this.inputErrorMessage.innerHTML = this.inputDomElement.title;
-    }
-    this.inputErrorMessage.classList.remove('hide');
+    this.invalidInput = new RegExp(pattern).test(value);
   }
 }
diff --git a/app/assets/javascripts/pages/sessions/new/index.js b/app/assets/javascripts/pages/sessions/new/index.js
index e1a3f42a71f..3f5a3e15c2c 100644
--- a/app/assets/javascripts/pages/sessions/new/index.js
+++ b/app/assets/javascripts/pages/sessions/new/index.js
@@ -1,4 +1,5 @@
 import $ from 'jquery';
+import LengthValidator from './length_validator';
 import UsernameValidator from './username_validator';
 import NoEmojiValidator from '../../../emoji/no_emoji_validator';
 import SigninTabsMemoizer from './signin_tabs_memoizer';
@@ -6,6 +7,7 @@ import OAuthRememberMe from './oauth_remember_me';
 import preserveUrlFragment from './preserve_url_fragment';
 
 document.addEventListener('DOMContentLoaded', () => {
+  new LengthValidator(); // eslint-disable-line no-new
   new UsernameValidator(); // eslint-disable-line no-new
   new SigninTabsMemoizer(); // eslint-disable-line no-new
   new NoEmojiValidator(); // eslint-disable-line no-new
diff --git a/app/assets/javascripts/pages/sessions/new/length_validator.js b/app/assets/javascripts/pages/sessions/new/length_validator.js
new file mode 100644
index 00000000000..3d687ca08cc
--- /dev/null
+++ b/app/assets/javascripts/pages/sessions/new/length_validator.js
@@ -0,0 +1,32 @@
+import InputValidator from '../../../validators/input_validator';
+
+const errorMessageClass = 'gl-field-error';
+
+export default class LengthValidator extends InputValidator {
+  constructor(opts = {}) {
+    super();
+
+    const container = opts.container || '';
+    const validateLengthElements = document.querySelectorAll(`${container} .js-validate-length`);
+
+    validateLengthElements.forEach(element =>
+      element.addEventListener('input', this.eventHandler.bind(this)),
+    );
+  }
+
+  eventHandler(event) {
+    this.inputDomElement = event.target;
+    this.inputErrorMessage = this.inputDomElement.parentElement.querySelector(
+      `.${errorMessageClass}`,
+    );
+
+    const { value } = this.inputDomElement;
+    const { maxLengthMessage, maxLength } = this.inputDomElement.dataset;
+
+    this.errorMessage = maxLengthMessage;
+
+    this.invalidInput = value.length > parseInt(maxLength, 10);
+
+    this.setValidationStateAndMessage();
+  }
+}
diff --git a/app/assets/javascripts/validators/input_validator.js b/app/assets/javascripts/validators/input_validator.js
new file mode 100644
index 00000000000..f37373977b8
--- /dev/null
+++ b/app/assets/javascripts/validators/input_validator.js
@@ -0,0 +1,34 @@
+const invalidInputClass = 'gl-field-error-outline';
+
+export default class InputValidator {
+  constructor() {
+    this.inputDomElement = {};
+    this.inputErrorMessage = {};
+    this.errorMessage = null;
+    this.invalidInput = null;
+  }
+
+  setValidationStateAndMessage() {
+    this.setValidationMessage();
+
+    const isInvalidInput = !this.inputDomElement.checkValidity();
+    this.inputDomElement.classList.toggle(invalidInputClass, isInvalidInput);
+    this.inputErrorMessage.classList.toggle('hide', !isInvalidInput);
+  }
+
+  setValidationMessage() {
+    if (this.invalidInput) {
+      this.inputDomElement.setCustomValidity(this.errorMessage);
+      this.inputErrorMessage.innerHTML = this.errorMessage;
+    } else {
+      this.resetValidationMessage();
+    }
+  }
+
+  resetValidationMessage() {
+    if (this.inputDomElement.validationMessage === this.errorMessage) {
+      this.inputDomElement.setCustomValidity('');
+      this.inputErrorMessage.innerHTML = this.inputDomElement.title;
+    }
+  }
+}