added keys to components when added to an array so react knows what was added and removed correctly w/ burnettk (#1180)

Co-authored-by: jasquat <jasquat@users.noreply.github.com>

spiffworkflow-frontend/src/helpers.tsx

@@ -1,6 +1,6 @@
 import { Buffer } from 'buffer';
 
-import { ProcessInstance } from './interfaces';
+import { ElementForArray, ProcessInstance } from './interfaces';
 
 export const DEFAULT_PER_PAGE = 50;
 export const DEFAULT_PAGE = 1;
@@ -300,3 +300,13 @@ export const isURL = (str: string) => {
     /^(?:(?:(?:https?|ftp):)?\/\/)(?:\S+(?::\S*)?@)?(?:(?!(?:10|127)(?:\.\d{1,3}){3})(?!(?:169\.254|192\.168)(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[a-z\u00a1-\uffff]{2,})))(?::\d{2,5})?(?:[/?#]\S*)?$/i;
   return urlRegex.test(str);
 };
+
+// this will help maintain order when using an array of elements.
+// React needs to have a key for each component to ensure correct elements are added
+// and removed when that array is changed.
+// https://stackoverflow.com/questions/46735483/error-do-not-use-array-index-in-keys/46735689#46735689
+export const renderElementsForArray = (elements: ElementForArray[]) => {
+  return elements.map((element: any) => (
+    <div key={element.key}>{element.component}</div>
+  ));
+};

spiffworkflow-frontend/src/interfaces.ts

@@ -1,3 +1,5 @@
+import { ReactElement } from 'react';
+
 export interface User {
   id: number;
   username: string;
@@ -496,3 +498,8 @@ export interface SpiffTableHeader {
   tooltip_text?: string;
   text: string;
 }
+
+export interface ElementForArray {
+  key: string;
+  component: ReactElement | null;
+}

spiffworkflow-frontend/src/routes/TaskShow.tsx

@@ -10,10 +10,12 @@ import {
   doNothing,
   modifyProcessIdentifierForPathParam,
   recursivelyChangeNullAndUndefined,
+  renderElementsForArray,
   setPageTitle,
 } from '../helpers';
 import {
   BasicTask,
+  ElementForArray,
   ErrorForDisplay,
   EventDefinition,
   HotCrumbItem,
@@ -446,7 +448,7 @@ export default function TaskShow() {
     );
   };
 
-  const pageElements = [];
+  const pageElements: ElementForArray[] = [];
   if (basicTask) {
     let statusString = '';
     if (basicTask.state !== 'READY') {
@@ -457,28 +459,38 @@ export default function TaskShow() {
       !('allowGuest' in basicTask.extensions) ||
       basicTask.extensions.allowGuest !== 'true'
     ) {
-      pageElements.push(<ProcessBreadcrumb hotCrumbs={hotCrumbs} />);
+      pageElements.push({
-      pageElements.push(
+        key: 'process-breadcrumb',
+        component: <ProcessBreadcrumb hotCrumbs={hotCrumbs} />,
+      });
+      pageElements.push({
+        key: 'task-name',
+        component: (
           <h3>
             Task: {basicTask.name_for_display} (
             {basicTask.process_model_display_name}){statusString}
           </h3>
-      );
+        ),
+      });
     }
   }
 
   if (guestConfirmationText) {
-    pageElements.push(
+    pageElements.push({
+      key: 'guest-confirmation-text',
+      component: (
         <MarkdownRenderer linkTarget="_blank" source={guestConfirmationText} />
-    );
+      ),
+    });
   } else if (basicTask && taskData) {
-    pageElements.push(<InstructionsForEndUser task={taskWithTaskData} />);
+    pageElements.push({
-    pageElements.push(formElement());
+      key: 'instructions-for-end-user',
+      component: <InstructionsForEndUser task={taskWithTaskData} />,
+    });
+    pageElements.push({ key: 'main-form', component: formElement() });
   } else if (!atLeastOneTaskFetchHasError) {
-    pageElements.push(getLoadingIcon());
+    pageElements.push({ key: 'loading-icon', component: getLoadingIcon() });
   }
 
-  // typescript gets angry if we return an array of elements not in a tag
+  return <>{renderElementsForArray(pageElements)}</>;
-  // eslint-disable-next-line react/jsx-no-useless-fragment
-  return <>{pageElements}</>;
 }