[JN-505] Save survey drafts to local storage (#495)

populate/lombok.config

@@ -1,3 +1,2 @@
 # This file is generated by the 'io.freefair.lombok' Gradle plugin
 config.stopBubbling = true
-lombok.extern.findbugs.addSuppressFBWarnings = true

ui-admin/src/forms/designer/modals/DiscardLocalDraftModal.test.tsx

@@ -0,0 +1,46 @@
+import React from 'react'
+import { render, screen } from '@testing-library/react'
+import userEvent from '@testing-library/user-event'
+import DiscardLocalDraftModal from './DiscardLocalDraftModal'
+
+describe('DiscardLocalDraftModal', () => {
+  test('allows discarding drafts on exit', async () => {
+    //Arrange
+    const user = userEvent.setup()
+    const FORM_DRAFT_KEY = 'surveyDraft_testForm_12'
+    render(<DiscardLocalDraftModal
+      formDraftKey={FORM_DRAFT_KEY}
+      onExit={() => jest.fn()}
+      onSaveDraft={() => jest.fn()}
+      onDismiss={() => jest.fn()}
+    />)
+
+    //Act
+    jest.spyOn(Storage.prototype, 'removeItem')
+    const exitAndDiscardButton = screen.getByText('Exit & discard draft')
+    await user.click(exitAndDiscardButton)
+
+    //Assert
+    expect(localStorage.removeItem).toHaveBeenCalledWith(FORM_DRAFT_KEY)
+  })
+
+  test('allows keeping drafts on exit', async () => {
+    //Arrange
+    const user = userEvent.setup()
+    const FORM_DRAFT_KEY = 'surveyDraft_testForm_12'
+    render(<DiscardLocalDraftModal
+      formDraftKey={FORM_DRAFT_KEY}
+      onExit={() => jest.fn()}
+      onSaveDraft={() => jest.fn()}
+      onDismiss={() => jest.fn()}
+    />)
+
+    //Act
+    jest.spyOn(Storage.prototype, 'removeItem')
+    const exitAndDiscardButton = screen.getByText('Exit & save draft')
+    await user.click(exitAndDiscardButton)
+
+    //Assert
+    expect(localStorage.removeItem).not.toHaveBeenCalled()
+  })
+})

ui-admin/src/forms/designer/modals/DiscardLocalDraftModal.tsx

@@ -0,0 +1,54 @@
+import { Modal, ModalFooter } from 'react-bootstrap'
+import { Button } from 'components/forms/Button'
+import React from 'react'
+import { deleteDraft } from '../utils/formDraftUtils'
+
+/**
+ * Modal presenting the user with the option to discard a local draft. Shown on Cancel if there is a local draft.
+ */
+const DiscardLocalDraftModal = ({ formDraftKey, onExit, onSaveDraft, onDismiss }: {
+  formDraftKey: string
+  onExit: () => void
+  onSaveDraft: () => void
+  onDismiss: () => void
+}) => {
+  return <Modal show={true} onHide={onDismiss}>
+    <Modal.Header>
+      <Modal.Title>Unsaved Changes</Modal.Title>
+    </Modal.Header>
+    <Modal.Body>
+      <p>Are you sure you want to cancel? You have an unsaved survey draft. You can save the
+        draft and return to edit it later, or discard the draft if it is no longer needed.</p>
+    </Modal.Body>
+    <ModalFooter>
+      <Button
+        variant="primary"
+        onClick={() => {
+          onSaveDraft()
+          onDismiss()
+          onExit()
+        }}
+      >
+        Exit & save draft
+      </Button>
+      <Button
+        variant="danger"
+        onClick={() => {
+          deleteDraft({ formDraftKey })
+          onDismiss()
+          onExit()
+        }}
+      >
+        Exit & discard draft
+      </Button>
+      <Button
+        variant="secondary"
+        onClick={onDismiss}
+      >
+        Cancel
+      </Button>
+    </ModalFooter>
+  </Modal>
+}
+
+export default DiscardLocalDraftModal

ui-admin/src/forms/designer/modals/LoadedLocalDraftModal.tsx

@@ -0,0 +1,32 @@
+import React from 'react'
+import Modal from 'react-bootstrap/Modal'
+import { Button } from 'components/forms/Button'
+
+/**
+ * Shown to the user if the form editor is opened and we detect a local draft.
+ */
+const LoadedLocalDraftModal = ({ onDismiss, lastUpdated }: {
+  onDismiss: () => void
+  lastUpdated: number | undefined
+}) => {
+  return <Modal show={true} onHide={onDismiss}>
+    <Modal.Header>
+      <Modal.Title>Survey Draft Loaded</Modal.Title>
+    </Modal.Header>
+    <Modal.Body>
+      <p>A previously unsaved survey draft was automatically loaded.
+        Be sure to save the survey in order to publish your changes.</p>
+      {lastUpdated && <span>This draft was last updated {new Date(lastUpdated).toLocaleString()}</span> }
+    </Modal.Body>
+    <Modal.Footer>
+      <Button
+        variant="primary"
+        onClick={onDismiss}
+      >
+        Continue
+      </Button>
+    </Modal.Footer>
+  </Modal>
+}
+
+export default LoadedLocalDraftModal

ui-admin/src/forms/designer/utils/formDraftUtils.tsx

@@ -0,0 +1,42 @@
+import { VersionedForm } from '@juniper/ui-core'
+
+export type FormDraft = {
+  content: string
+  date: number
+}
+
+/** returns a form draft key for local storage */
+export function getFormDraftKey({ form }: { form: VersionedForm }) {
+  return `formDraft_${form.stableId}_${form.version}`
+}
+
+/** returns a form draft from local storage, if there is one */
+export function getDraft({ formDraftKey }: { formDraftKey: string }): FormDraft | undefined {
+  const draft = localStorage.getItem(formDraftKey)
+  if (!draft) {
+    return undefined
+  } else {
+    const draftParsed: FormDraft = JSON.parse(draft)
+    return draftParsed
+  }
+}
+
+/** saves a form draft to local storage with the current timestamp, if there is one */
+export function saveDraft({ formDraftKey, draft, setSavingDraft }: {
+  formDraftKey: string,
+  draft: FormDraft
+  setSavingDraft: (saving: boolean) => void
+}) {
+  setSavingDraft(true)
+  localStorage.setItem(formDraftKey, JSON.stringify(draft))
+  //Saving a draft happens so quickly that the "Saving draft..." message isn't even visible to the user.
+  //Set a timeout to show it for 2 seconds so the user knows that their drafts are being saved.
+  setTimeout(() => {
+    setSavingDraft(false)
+  }, 2000)
+}
+
+/** deletes a form draft from local storage */
+export function deleteDraft({ formDraftKey }: { formDraftKey: string }) {
+  localStorage.removeItem(formDraftKey)
+}

ui-admin/src/study/surveys/SurveyEditorView.test.tsx

@@ -0,0 +1,52 @@
+import React from 'react'
+import { render, screen } from '@testing-library/react'
+import SurveyEditorView from './SurveyEditorView'
+import { getFormDraftKey } from '../../forms/designer/utils/formDraftUtils'
+import { VersionedForm } from '@juniper/ui-core'
+
+describe('SurveyEditorView', () => {
+  const mockForm: VersionedForm = {
+    id: 'testForm',
+    version: 12,
+    content: '{}',
+    stableId: 'testStableId',
+    name: '',
+    createdAt: 0,
+    lastUpdatedAt: 0
+  }
+
+  test('shows the user a LoadedLocalDraftModal when a draft is loaded', async () => {
+    //Arrange
+    const FORM_DRAFT_KEY = getFormDraftKey({ form: mockForm })
+    localStorage.setItem(FORM_DRAFT_KEY, JSON.stringify({}))
+
+    jest.spyOn(Storage.prototype, 'getItem')
+
+    render(<SurveyEditorView
+      currentForm={mockForm}
+      onCancel={jest.fn()}
+      onSave={jest.fn()}
+    />)
+
+    //Assert
+    const modalHeader = screen.getByText('Survey Draft Loaded')
+    expect(modalHeader).toBeInTheDocument()
+  })
+
+  test('checks local storage for a draft', async () => {
+    //Arrange
+    const FORM_DRAFT_KEY = getFormDraftKey({ form: mockForm })
+
+    jest.spyOn(Storage.prototype, 'getItem')
+
+    render(<SurveyEditorView
+      currentForm={mockForm}
+      onCancel={jest.fn()}
+      onSave={jest.fn()}
+    />)
+
+    //Assert
+    expect(localStorage.getItem).toHaveBeenCalledWith(FORM_DRAFT_KEY)
+    expect(screen.queryByText('Survey Draft Loaded')).not.toBeInTheDocument()
+  })
+})

ui-admin/src/study/surveys/SurveyEditorView.tsx

@@ -4,6 +4,10 @@ import { VersionedForm } from 'api/api'
 
 import { Button } from 'components/forms/Button'
 import { FormContentEditor } from 'forms/FormContentEditor'
+import LoadedLocalDraftModal from 'forms/designer/modals/LoadedLocalDraftModal'
+import DiscardLocalDraftModal from 'forms/designer/modals/DiscardLocalDraftModal'
+import { deleteDraft, FormDraft, getDraft, getFormDraftKey, saveDraft } from 'forms/designer/utils/formDraftUtils'
+import { useAutosaveEffect } from '@juniper/ui-core/build/autoSaveUtils'
 
 type SurveyEditorViewProps = {
   currentForm: VersionedForm
@@ -21,24 +25,62 @@ const SurveyEditorView = (props: SurveyEditorViewProps) => {
     onSave
   } = props
 
-  const [editedContent, setEditedContent] = useState<string>()
+  const FORM_DRAFT_KEY = getFormDraftKey({ form: currentForm })
+  const FORM_DRAFT_SAVE_INTERVAL = 10000
+
   const [isEditorValid, setIsEditorValid] = useState(true)
   const [saving, setSaving] = useState(false)
-  const isSaveEnabled = !!editedContent && isEditorValid && !saving
+  const [savingDraft, setSavingDraft] = useState(false)
+
+  //Let the user know if we loaded a draft from local storage when the component first renders. It's important
+  //for them to know if the version of the survey they're seeing are from a draft or are actually published.
+  const [showLoadedDraftModal, setShowLoadedDraftModal] = useState(!!getDraft({ formDraftKey: FORM_DRAFT_KEY }))
+  const [showDiscardDraftModal, setShowDiscardDraftModal] = useState(false)
+
+  const [draft, setDraft] = useState<FormDraft | undefined>(
+    !readOnly ? getDraft({ formDraftKey: FORM_DRAFT_KEY }) : undefined)
+
+  const isSaveEnabled = !!draft && isEditorValid && !saving
+
+  const saveDraftToLocalStorage = () => {
+    setDraft(currentDraft => {
+      if (currentDraft && currentDraft?.content !== getDraft({ formDraftKey: FORM_DRAFT_KEY })?.content) {
+        saveDraft({
+          formDraftKey: FORM_DRAFT_KEY,
+          draft: currentDraft,
+          setSavingDraft
+        })
+      }
+      return currentDraft
+    })
+  }
+
+  useAutosaveEffect(saveDraftToLocalStorage, FORM_DRAFT_SAVE_INTERVAL)
 
   const onClickSave = async () => {
     if (!isSaveEnabled) {
       return
     }
     setSaving(true)
     try {
-      await onSave({ content: editedContent })
-      setEditedContent(undefined)
+      await onSave({ content: draft?.content })
+      //Once we've persisted the form draft to the database, there's no need to keep it in local storage.
+      //Future drafts will have different FORM_DRAFT_KEYs anyway, as they're based on the form version number.
+      deleteDraft({ formDraftKey: FORM_DRAFT_KEY })
+      setDraft(undefined)
     } finally {
       setSaving(false)
     }
   }
 
+  const onClickCancel = () => {
+    if (draft) {
+      setShowDiscardDraftModal(true)
+    } else {
+      onCancel()
+    }
+  }
+
   return (
     <div className="SurveyView d-flex flex-column flex-grow-1 mx-1 mb-1">
       <div className="d-flex p-2 align-items-center">
@@ -47,12 +89,13 @@ const SurveyEditorView = (props: SurveyEditorViewProps) => {
             <span className="detail me-2 ms-2">version {currentForm.version}</span>
           </h5>
         </div>
+        { savingDraft && <span className="detail me-2 ms-2">Saving draft...</span> }
         {!readOnly && (
           <Button
             disabled={!isSaveEnabled}
             className="me-md-2"
             tooltip={(() => {
-              if (!editedContent) {
+              if (!draft) {
                 return 'Form is unchanged. Make changes to save.'
               }
               if (!isEditorValid) {
@@ -66,14 +109,31 @@ const SurveyEditorView = (props: SurveyEditorViewProps) => {
             Save
           </Button>
         )}
-        <button className="btn btn-secondary" type="button" onClick={onCancel}>Cancel</button>
+        <button className="btn btn-secondary" type="button"
+          onClick={onClickCancel}>Cancel</button>
+        { showLoadedDraftModal && draft &&
+            <LoadedLocalDraftModal
+              onDismiss={() => setShowLoadedDraftModal(false)}
+              lastUpdated={draft?.date}/>}
+        { showDiscardDraftModal && draft &&
+            <DiscardLocalDraftModal
+              formDraftKey={FORM_DRAFT_KEY}
+              onExit={() => onCancel()}
+              onSaveDraft={() =>
+                saveDraft({
+                  formDraftKey: FORM_DRAFT_KEY,
+                  draft,
+                  setSavingDraft
+                })}
+              onDismiss={() => setShowDiscardDraftModal(false)}
+            />}
       </div>
       <FormContentEditor
-        initialContent={currentForm.content}
+        initialContent={draft?.content || currentForm.content} //favor loading the draft, if we find one
         readOnly={readOnly}
         onChange={(isValid, newContent) => {
           if (isValid) {
-            setEditedContent(JSON.stringify(newContent))
+            setDraft({ content: JSON.stringify(newContent), date: Date.now() })
           }
           setIsEditorValid(isValid)
         }}

ui-core/src/autoSaveUtils.ts

@@ -0,0 +1,18 @@
+import { useEffect } from 'react'
+
+/** TODO JSdoc */
+export function useAutosaveEffect(saveFn: () => void, autoSaveInterval: number) {
+  useEffect(() => {
+    let timeoutHandle: number
+    // run saveFn at the specified interval
+    (function loop() {
+      timeoutHandle = window.setTimeout(() => {
+        saveFn()
+        loop()
+      }, autoSaveInterval)
+    })()
+    return () => {
+      window.clearTimeout(timeoutHandle)
+    }
+  }, [saveFn])
+}