Merge branch 'modal-focus-trap' into 'dev'

Introduce useFocusTrap hook and refactor Modal & Alert components

See merge request turris/reforis/foris-js!237

src/bootstrap/Alert.js

@@ -5,10 +5,12 @@
  * See /LICENSE for more information.
  */
 
-import React from "react";
+import React, { useRef } from "react";
 
 import PropTypes from "prop-types";
 
+import { useFocusTrap } from "../utils/hooks";
+
 export const ALERT_TYPES = Object.freeze({
     PRIMARY: "primary",
     SECONDARY: "secondary",
@@ -37,11 +39,15 @@ Alert.defaultProps = {
 };
 
 function Alert({ type, onDismiss, children }) {
+    const alertRef = useRef();
+    useFocusTrap(alertRef, !!onDismiss);
     return (
         <div
+            ref={alertRef}
             className={`alert alert-${type} ${
                 onDismiss ? "alert-dismissible" : ""
             }`.trim()}
+            role="alert"
         >
             {onDismiss && (
                 <button

src/bootstrap/Modal.js

@@ -9,7 +9,7 @@ import React, { useRef, useEffect } from "react";
 
 import PropTypes from "prop-types";
 
-import { useClickOutside } from "../utils/hooks";
+import { useClickOutside, useFocusTrap } from "../utils/hooks";
 import Portal from "../utils/Portal";
 import "./Modal.css";
 
@@ -29,10 +29,11 @@ Modal.propTypes = {
 };
 
 export function Modal({ shown, setShown, scrollable, size, children }) {
-    const dialogRef = useRef();
+    const modalRef = useRef();
     let modalSize = "modal-";
 
-    useClickOutside(dialogRef, () => setShown(false));
+    useClickOutside(modalRef, () => setShown(false));
+    useFocusTrap(modalRef, shown);
 
     useEffect(() => {
         const handleEsc = (event) => {
@@ -65,11 +66,13 @@ export function Modal({ shown, setShown, scrollable, size, children }) {
     return (
         <Portal containerId="modal-container">
             <div
+                ref={modalRef}
                 className={`modal fade ${shown ? "show" : ""}`.trim()}
                 role="dialog"
+                aria-modal="true"
+                aria-labelledby="modal-title"
             >
                 <div
-                    ref={dialogRef}
                     className={`${modalSize.trim()} modal-dialog modal-dialog-centered ${
                         scrollable ? "modal-dialog-scrollable" : ""
                     }`.trim()}
@@ -90,7 +93,7 @@ ModalHeader.propTypes = {
 export function ModalHeader({ setShown, title }) {
     return (
         <div className="modal-header">
-            <h5 className="modal-title">{title}</h5>
+            <h1 className="modal-title fs-5">{title}</h1>
             <button
                 type="button"
                 className="btn-close"

src/common/__tests__/__snapshots__/RebootButton.test.js.snap

@@ -6,6 +6,8 @@ exports[`<RebootButton/> Render modal. 1`] = `
     id="modal-container"
   >
     <div
+      aria-labelledby="modal-title"
+      aria-modal="true"
       class="modal fade show"
       role="dialog"
     >
@@ -19,11 +21,11 @@ exports[`<RebootButton/> Render modal. 1`] = `
           <div
             class="modal-header"
           >
-            <h5
-              class="modal-title"
+            <h1
+              class="modal-title fs-5"
             >
               Warning!
-            </h5>
+            </h1>
             <button
               aria-label="Close"
               class="btn-close"

src/context/alertContext/__tests__/__snapshots__/AlertContext.test.js.snap

@@ -7,6 +7,7 @@ exports[`AlertContext should render alert 1`] = `
   >
     <div
       class="alert alert-danger alert-dismissible"
+      role="alert"
     >
       <button
         aria-label="Close"

src/utils/hooks.js

@@ -40,3 +40,40 @@ export function useClickOutside(element, callback) {
         };
     });
 }
+
+/* Trap focus inside element. */
+export function useFocusTrap(elementRef, condition = true) {
+    useEffect(() => {
+        if (!condition) {
+            return;
+        }
+        const currentElement = elementRef.current;
+        const focusableElements = currentElement.querySelectorAll(
+            'button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])'
+        );
+        const firstElement = focusableElements[0];
+        const lastElement = focusableElements[focusableElements.length - 1];
+
+        const handleTab = (event) => {
+            if (event.key === "Tab") {
+                if (event.shiftKey) {
+                    if (document.activeElement === firstElement) {
+                        lastElement.focus();
+                        event.preventDefault();
+                    }
+                } else if (document.activeElement === lastElement) {
+                    firstElement.focus();
+                    event.preventDefault();
+                }
+            }
+        };
+
+        currentElement.addEventListener("keydown", handleTab);
+
+        firstElement.focus();
+
+        return () => {
+            currentElement.removeEventListener("keydown", handleTab);
+        };
+    }, [elementRef, condition]);
+}