Use non-optional Celery for PDF generation

aleksis/core/util/pdf.py

 import glob
 import os
 import subprocess  # noqa
-from typing import Union
 
 from django.http.request import HttpRequest
 from django.http.response import HttpResponse
@@ -11,21 +10,16 @@ from django.utils.translation import gettext as _
 
 from celery_progress.backend import ProgressRecorder
 
+from aleksis.core.celery import app
 from aleksis.core.settings import MEDIA_ROOT, MEDIA_URL, STATIC_ROOT
-from aleksis.core.util.core_helpers import (
-    DummyRecorder,
-    celery_optional,
-    celery_optional_progress,
-    is_celery_enabled,
-    make_temp_file,
-    path_and_rename,
-)
-
-
-@celery_optional_progress
-def generate_pdf(recorder: Union[ProgressRecorder, DummyRecorder], html_code: str, pdf_path: str):
+from aleksis.core.util.celery_progress import recorded_task
+from aleksis.core.util.core_helpers import make_temp_file, path_and_rename
+
+
+@recorded_task
+def generate_pdf(html_code: str, pdf_path: str, recorder: ProgressRecorder):
     """Generate a PDF file by rendering the HTML code using electron-pdf."""
-    recorder.total = 1
+    recorder.set_progress(0, 1)
 
     # Replace /static with STATIC_ROOT to get local file system paths
     html_code = html_code.replace("/static", STATIC_ROOT)
@@ -37,13 +31,17 @@ def generate_pdf(recorder: Union[ProgressRecorder, DummyRecorder], html_code: st
 
     # Start a X framebuffer and run electron-pdf
     os.environ["DISPLAY"] = ":99.0"
-    xfvb_process= subprocess.Popen(["Xvfb", ":99", "-screen", "0", "1024x768x24"], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+    xfvb_process = subprocess.Popen(  # noqa
+        ["Xvfb", ":99", "-screen", "0", "1024x768x24"],
+        stdout=subprocess.DEVNULL,
+        stderr=subprocess.DEVNULL,
+    )
     subprocess.run(["electron-pdf", path, pdf_path])  # noqa
     xfvb_process.terminate()
 
     os.remove(path)
 
-    recorder.set_progress(1)
+    recorder.set_progress(1, 1)
 
 
 def render_pdf(request: HttpRequest, template_name: str, context: dict = None) -> HttpResponse:
@@ -61,34 +59,30 @@ def render_pdf(request: HttpRequest, template_name: str, context: dict = None) -
 
     html_template = render_to_string(template_name, context)
 
-    if is_celery_enabled():
-        result = generate_pdf(html_template, os.path.join(MEDIA_ROOT, pdf_path))
-
-        context = {
-            "title": _("Progress: Generate PDF file"),
-            "back_url": context.get("back_url", "index"),
-            "progress": {
-                "task_id": result.task_id,
-                "title": _("Generating PDF file …"),
-                "success": _("The PDF file has been generated successfully."),
-                "error": _("There was a problem while generating the PDF file."),
-                "redirect_on_success": MEDIA_URL + pdf_path,
-            },
-            "additional_button": {
-                "href": MEDIA_URL + pdf_path,
-                "caption": _("Download PDF"),
-                "icon": "picture_as_pdf",
-            },
-        }
-
-        # Render progress view
-        return render(request, "core/pages/progress.html", context)
-    else:
-        # Render PaperCSS view if Celery isn't enabled
-        return render(request, template_name, context)
-
-
-@celery_optional
+    result = generate_pdf.delay(html_template, os.path.join(MEDIA_ROOT, pdf_path))
+
+    context = {
+        "title": _("Progress: Generate PDF file"),
+        "back_url": context.get("back_url", "index"),
+        "progress": {
+            "task_id": result.task_id,
+            "title": _("Generating PDF file …"),
+            "success": _("The PDF file has been generated successfully."),
+            "error": _("There was a problem while generating the PDF file."),
+            "redirect_on_success": MEDIA_URL + pdf_path,
+        },
+        "additional_button": {
+            "href": MEDIA_URL + pdf_path,
+            "caption": _("Download PDF"),
+            "icon": "picture_as_pdf",
+        },
+    }
+
+    # Render progress view
+    return render(request, "core/pages/progress.html", context)
+
+
+@app.task
 def clean_up_pdf_directory() -> None:
     """Clean up directory with generated PDF files."""
     files = glob.glob(os.path.join(MEDIA_ROOT, "pdfs", "*.pdf"))