1 files changed, 167 insertions, 0 deletions
diff --git a/app/assets/javascripts/gl_field_errors.js.es6 b/app/assets/javascripts/gl_field_errors.js.es6
new file mode 100644
index 00000000000..8657e7b4abf
--- /dev/null
+++ b/app/assets/javascripts/gl_field_errors.js.es6
@@ -0,0 +1,167 @@
+((global) => {
+  /*
+   * This class overrides the browser's validation error bubbles, displaying custom
+   * error messages for invalid fields instead. To begin validating any form, add the
+   * class `show-gl-field-errors` to the form element, and ensure error messages are
+   * declared in each inputs' title attribute.
+   *
+   * Example:
+   *
+   * <form class='show-gl-field-errors'>
+   *  <input type='text' name='username' title='Username is required.'/>
+   *</form>
+   *
+    * */
+
+  const errorMessageClass = 'gl-field-error';
+  const inputErrorClass = 'gl-field-error-outline';
+
+  class GlFieldError {
+    constructor({ input, formErrors }) {
+      this.inputElement = $(input);
+      this.inputDomElement = this.inputElement.get(0);
+      this.form = formErrors;
+      this.errorMessage = this.inputElement.attr('title') || 'This field is required.';
+      this.fieldErrorElement = $(`<p class='${errorMessageClass} hide'>${ this.errorMessage }</p>`);
+
+      this.state = {
+        valid: false,
+        empty: true
+      };
+
+      this.initFieldValidation();
+    }
+
+    initFieldValidation() {
+      // hidden when injected into DOM
+      this.inputElement.after(this.fieldErrorElement);
+      this.inputElement.off('invalid').on('invalid', this.handleInvalidSubmit.bind(this));
+      this.scopedSiblings = this.safelySelectSiblings();
+    }
+
+    safelySelectSiblings() {
+      // Apply `ignoreSelector` in markup to siblings whose visibility should not be toggled with input validity
+      const ignoreSelector = '.validation-ignore';
+      const unignoredSiblings = this.inputElement.siblings(`p:not(${ignoreSelector})`);
+      const parentContainer = this.inputElement.parent('.form-group');
+
+      // Only select siblings when they're scoped within a form-group with one input
+      const safelyScoped = parentContainer.length && parentContainer.find('input').length === 1;
+
+      return safelyScoped ? unignoredSiblings : this.fieldErrorElement;
+    }
+
+    renderValidity() {
+      this.renderClear();
+
+      if (this.state.valid) {
+        return this.renderValid();
+      }
+
+      if (this.state.empty) {
+        return this.renderEmpty();
+      }
+
+      if (!this.state.valid) {
+        return this.renderInvalid();
+      }
+
+    }
+
+    handleInvalidSubmit(event) {
+      event.preventDefault();
+      const currentValue = this.accessCurrentValue();
+      this.state.valid = false;
+      this.state.empty = currentValue === '';
+
+      this.renderValidity();
+      this.form.focusOnFirstInvalid.apply(this.form);
+      // For UX, wait til after first invalid submission to check each keyup
+      this.inputElement.off('keyup.field_validator')
+        .on('keyup.field_validator', this.updateValidity.bind(this));
+
+    }
+
+    /* Get or set current input value */
+    accessCurrentValue(newVal) {
+      return newVal ? this.inputElement.val(newVal) : this.inputElement.val();
+    }
+
+    getInputValidity() {
+      return this.inputDomElement.validity.valid;
+    }
+
+    updateValidity() {
+      const inputVal = this.accessCurrentValue();
+      this.state.empty = !inputVal.length;
+      this.state.valid = this.getInputValidity();
+      this.renderValidity();
+    }
+
+    renderValid() {
+      return this.renderClear();
+    }
+
+    renderEmpty() {
+      return this.renderInvalid();
+    }
+
+    renderInvalid() {
+      this.inputElement.addClass(inputErrorClass);
+      this.scopedSiblings.hide();
+      return this.fieldErrorElement.show();
+    }
+
+    renderClear() {
+      const inputVal = this.accessCurrentValue();
+      if (!inputVal.split(' ').length) {
+        const trimmedInput = inputVal.trim();
+        this.accessCurrentValue(trimmedInput);
+      }
+      this.inputElement.removeClass(inputErrorClass);
+      this.scopedSiblings.hide();
+      this.fieldErrorElement.hide();
+    }
+  }
+
+  const customValidationFlag = 'no-gl-field-errors';
+
+  class GlFieldErrors {
+    constructor(form) {
+      this.form = $(form);
+      this.state = {
+        inputs: [],
+        valid: false
+      };
+      this.initValidators();
+    }
+
+    initValidators () {
+      // select all non-hidden inputs in form
+      this.state.inputs = this.form.find(':input:not([type=hidden])').toArray()
+        .filter((input) => !input.classList.contains(customValidationFlag))
+        .map((input) => new GlFieldError({ input, formErrors: this }));
+
+      this.form.on('submit', this.catchInvalidFormSubmit);
+    }
+
+    /* Neccessary to prevent intercept and override invalid form submit
+     * because Safari & iOS quietly allow form submission when form is invalid
+     * and prevents disabling of invalid submit button by application.js */
+
+    catchInvalidFormSubmit (event) {
+      if (!event.currentTarget.checkValidity()) {
+        event.preventDefault();
+        event.stopPropagation();
+      }
+    }
+
+    focusOnFirstInvalid () {
+      const firstInvalid = this.state.inputs.filter((input) => !input.inputDomElement.validity.valid)[0];
+      firstInvalid.inputElement.focus();
+    }
+  }
+
+  global.GlFieldErrors = GlFieldErrors;
+
+})(window.gl || (window.gl = {}));