ABC class for JobMiddleware

Author: davegaeddert

plain-jobs/plain/jobs/__init__.py

@@ -1,4 +1,5 @@
 from .jobs import Job
+from .middleware import JobMiddleware
 from .registry import register_job
 
-__all__ = ["Job", "register_job"]
+__all__ = ["Job", "JobMiddleware", "register_job"]

plain-jobs/plain/jobs/middleware.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+from abc import ABC, abstractmethod
 from collections.abc import Callable
 from typing import TYPE_CHECKING
 
@@ -9,11 +10,32 @@
     from .models import JobProcess, JobResult
 
 
-class AppLoggerMiddleware:
-    def __init__(self, run_job: Callable[[JobProcess], JobResult]) -> None:
+class JobMiddleware(ABC):
+    """
+    Abstract base class for job middleware.
+
+    Subclasses must implement process_job() to handle the job execution cycle.
+
+    Example:
+        class MyJobMiddleware(JobMiddleware):
+            def process_job(self, job: JobProcess) -> JobResult:
+                # Pre-processing
+                result = self.run_job(job)
+                # Post-processing
+                return result
+    """
+
+    def __init__(self, run_job: Callable[[JobProcess], JobResult]):
         self.run_job = run_job
 
-    def __call__(self, job: JobProcess) -> JobResult:
+    @abstractmethod
+    def process_job(self, job: JobProcess) -> JobResult:
+        """Process the job and return a result. Must be implemented by subclasses."""
+        ...
+
+
+class AppLoggerMiddleware(JobMiddleware):
+    def process_job(self, job: JobProcess) -> JobResult:
         with app_logger.include_context(
             job_request_uuid=str(job.job_request_uuid), job_process_uuid=str(job.uuid)
         ):

plain-jobs/plain/jobs/workers.py

@@ -327,7 +327,7 @@ def middleware_chain(job: JobProcess) -> JobResult:
         for middleware_path in reversed(settings.JOBS_MIDDLEWARE):
             middleware_class = import_string(middleware_path)
             middleware_instance = middleware_class(middleware_chain)
-            middleware_chain = middleware_instance
+            middleware_chain = middleware_instance.process_job
 
         job_result = middleware_chain(job_process)