Fix background assembly waiting after task result expiration

docassemble/AssemblyLine/data/questions/al_document.yml

@@ -139,13 +139,48 @@
 ---
 ############## Background document assembly #################
 ---
+# Use these saved completion variables in interview order blocks. Celery's
+# task.ready() becomes False again when its result expires (normally one day).
+# Error callbacks also save durable state. While waiting, check completed tasks
+# for failures from before these callbacks existed. failed() can block, so it
+# must only be called after ready(). Neither is needed when a saved result exists.
 generic object: ALDocumentBundle
 code: |
+  x.generate_downloads_task
+  if not defined(x.attr_name("_downloadable_files")):
+    if defined(x.attr_name("_download_error")) or (
+      x.generate_downloads_task.ready() and x.generate_downloads_task.failed()
+    ):
+      x.downloads_error_screen
+    al_download_waiting_screen
+  x.downloads_ready = True
+---
+generic object: ALDocumentBundle
+code: |
+  x.generate_downloads_with_docx_task
+  if not defined(x.attr_name("_downloadable_files")):
+    if defined(x.attr_name("_download_error")) or (
+      x.generate_downloads_with_docx_task.ready() and x.generate_downloads_with_docx_task.failed()
+    ):
+      x.downloads_error_screen
+    al_download_waiting_screen
+  x.downloads_with_docx_ready = True
+---
+generic object: ALDocumentBundle
+code: |
+  undefine(
+    x.attr_name("_downloadable_files"),
+    x.attr_name("_download_error"),
+    x.attr_name("downloads_ready"),
+    x.attr_name("downloads_with_docx_ready"),
+    x.attr_name("generate_downloads_with_docx_task"),
+  )
   x.generate_downloads_task = background_action(x.attr_name("create_downloads"))
 ---
 generic object: ALDocumentBundle
 event: x.create_downloads
 code: |
+  background_error_action(x.attr_name("save_download_error"))
   download_response = x.get_cacheable_documents(
     key="final", pdf=True, include_full_pdf=True
   )
@@ -155,13 +190,21 @@
 ---
 generic object: ALDocumentBundle
 code: |
+  undefine(
+    x.attr_name("_downloadable_files"),
+    x.attr_name("_download_error"),
+    x.attr_name("downloads_ready"),
+    x.attr_name("downloads_with_docx_ready"),
+    x.attr_name("generate_downloads_task"),
+  )
   x.generate_downloads_with_docx_task = background_action(
     x.attr_name("create_downloads_with_docx")
   )
 ---
 generic object: ALDocumentBundle
 event: x.create_downloads_with_docx
 code: |
+  background_error_action(x.attr_name("save_download_error"))
   download_response = x.get_cacheable_documents(
     key="final", pdf=True, docx=True, include_full_pdf=True
   )
@@ -176,13 +219,37 @@
 
   background_response()
 ---
+generic object: ALDocumentBundle
+event: x.save_download_error
+code: |
+  x._download_error = True
+  background_response()
+---
+generic object: ALDocumentBundle
+event: x.downloads_error_screen
+id: background downloads error screen
+question: |
+  We could not make your documents
+subquestion: |
+  Your answers have been saved. You can try again.
+
+  ${ action_button_html(url_action(x.attr_name('retry_downloads')), label='Try again') }
+---
+generic object: ALDocumentBundle
+event: x.retry_downloads
+code: |
+  if defined(x.attr_name("generate_downloads_with_docx_task")):
+    reconsider(x.attr_name("generate_downloads_with_docx_task"))
+  else:
+    reconsider(x.attr_name("generate_downloads_task"))
+---
 id: waiting screen
 question: |
   Please wait while we make your documents
 subquestion: |
   This can take a few minutes.
 
   <div class="spinner-border text-primary d-flex justify-content-center" role="status">
       <span class="sr-only visually-hidden">Making documents...</span>
   </div>
 event: al_download_waiting_screen
@@ -192,11 +259,28 @@
 ---
 generic object: ALDocumentBundle
 code: |
+  x.generate_preview_task
+  if not defined(x.attr_name("_preview_file")):
+    if defined(x.attr_name("_preview_error")) or (
+      x.generate_preview_task.ready() and x.generate_preview_task.failed()
+    ):
+      x.preview_error_screen
+    al_preview_waiting_screen
+  x.preview_ready = True
+---
+generic object: ALDocumentBundle
+code: |
+  undefine(
+    x.attr_name("_preview_file"),
+    x.attr_name("_preview_error"),
+    x.attr_name("preview_ready"),
+  )
   x.generate_preview_task = background_action(x.attr_name("generate_preview_event"))
 ---
 generic object: ALDocumentBundle
 event: x.generate_preview_event
 code: |
+  background_error_action(x.attr_name("save_preview_error"))
   preview_response = x.as_pdf(key="preview")
   background_response_action(
     x.attr_name("save_preview"), preview_response=preview_response
@@ -208,13 +292,34 @@
   x._preview_file = action_argument("preview_response")
   background_response()
 ---
+generic object: ALDocumentBundle
+event: x.save_preview_error
+code: |
+  x._preview_error = True
+  background_response()
+---
+generic object: ALDocumentBundle
+event: x.preview_error_screen
+id: background preview error screen
+question: |
+  We could not generate a preview of your document
+subquestion: |
+  Your answers have been saved. You can try again.
+
+  ${ action_button_html(url_action(x.attr_name('retry_preview')), label='Try again') }
+---
+generic object: ALDocumentBundle
+event: x.retry_preview
+code: |
+  reconsider(x.attr_name("generate_preview_task"))
+---
 id: preview waiting screen
 question: |
   Please wait while we generate a preview of your document
 subquestion: |
   This can take a few minutes.
 
   <div class="spinner-border text-primary d-flex justify-content-center" role="status">
       <span class="sr-only visually-hidden">Generating preview...</span>
   </div>
 event: al_preview_waiting_screen

docassemble/AssemblyLine/data/questions/test_aldocument_background_assembly.yml

@@ -8,12 +8,10 @@ metadata:
 mandatory: True
 code: |
   intro_screen
-  if not al_user_bundle.generate_preview_task.ready():
-    al_preview_waiting_screen
+  al_user_bundle.preview_ready
   preview_screen
-  # if not al_user_bundle.generate_downloads_task.ready(): # Without DOCX
-  if not al_user_bundle.generate_downloads_with_docx_task.ready():  # With DOCX
-    al_download_waiting_screen
+  # Use al_user_bundle.downloads_ready for PDF-only downloads.
+  al_user_bundle.downloads_with_docx_ready
   download_screen
 ---
 id: intro-screen
@@ -40,6 +38,15 @@ subquestion: |
   Your documents are ready for download.
 
   ${ al_user_bundle.download_list_html(use_previously_cached_files=True, include_full_pdf=True) }
+
+  ${ action_button_html(url_action('regenerate_downloads'), label='Regenerate documents') }
+---
+# Use this action after collecting any changed attachment inputs. Starting the
+# task clears its old saved files and completion gate; the order block waits for
+# the replacement files. Do not reconsider the task on every mandatory pass.
+event: regenerate_downloads
+code: |
+  reconsider("al_user_bundle.generate_downloads_with_docx_task")
 ---
 objects:
   - al_user_bundle: ALDocumentBundle.using(