Add Option to configure renderers in Django settings [follow-on to #158…

…] (#163)

* Add Option to configure renderers in Django settings

* Run precommit hook on all files

* Incorporate the review feedback

- Add output_file_extension attribute to the Renderer class
- Use PYINSTRUMENT_PROFILE_DIR_RENDERER setting variable

* Update pyinstrument/middleware.py

* Remove exit condition and use html renderer when render is missing

* Tidy up, raise error on misconfig

* pre-commit fixes

Co-authored-by: Kracekumar <me@kracekumar.com>
Co-authored-by: pre-commit <pre-commit@example.com>

docs/guide.md

@@ -122,6 +122,10 @@ def custom_show_pyinstrument(request):
 PYINSTRUMENT_SHOW_CALLBACK = "%s.custom_show_pyinstrument" % __name__
 ```
 
+You can configure the profile output type using setting's variable `PYINSTRUMENT_PROFILE_DIR_RENDERER`.
+Default value is `pyinstrument.renderers.HTMLRenderer`. The supported renderers are
+`pyinstrument.renderers.JSONRenderer`, `pyinstrument.renderers.HTMLRenderer`.
+
 ### Profile a web request in Flask
 
 A simple setup to profile a Flask application is the following:

pyinstrument/middleware.py

@@ -8,6 +8,7 @@
 from django.utils.module_loading import import_string
 
 from pyinstrument import Profiler
+from pyinstrument.renderers import Renderer
 from pyinstrument.renderers.html import HTMLRenderer
 
 try:
@@ -16,6 +17,23 @@
     MiddlewareMixin = object
 
 
+def get_renderer(path) -> Renderer:
+    """Return the renderer instance."""
+    if path:
+        try:
+            renderer = import_string(path)()
+        except ImportError as exc:
+            print("Unable to import the class: %s" % path)
+            raise exc
+
+        if not isinstance(renderer, Renderer):
+            raise ValueError(f"Renderer should subclass: {Renderer}")
+
+        return renderer
+    else:
+        return HTMLRenderer()
+
+
 class ProfilerMiddleware(MiddlewareMixin):  # type: ignore
     def process_request(self, request):
         profile_dir = getattr(settings, "PYINSTRUMENT_PROFILE_DIR", None)
@@ -41,8 +59,10 @@ def process_response(self, request, response):
         if hasattr(request, "profiler"):
             profile_session = request.profiler.stop()
 
-            renderer = HTMLRenderer()
-            output_html = renderer.render(profile_session)
+            configured_renderer = getattr(settings, "PYINSTRUMENT_PROFILE_DIR_RENDERER", None)
+            renderer = get_renderer(configured_renderer)
+
+            output = renderer.render(profile_session)
 
             profile_dir = getattr(settings, "PYINSTRUMENT_PROFILE_DIR", None)
 
@@ -55,10 +75,11 @@ def process_response(self, request, response):
                 path = path.replace("?", "_qs_")
 
             if profile_dir:
-                filename = "{total_time:.3f}s {path} {timestamp:.0f}.html".format(
+                filename = "{total_time:.3f}s {path} {timestamp:.0f}.{ext}".format(
                     total_time=profile_session.duration,
                     path=path,
                     timestamp=time.time(),
+                    ext=renderer.output_file_extension,
                 )
 
                 file_path = os.path.join(profile_dir, filename)
@@ -67,10 +88,15 @@ def process_response(self, request, response):
                     os.mkdir(profile_dir)
 
                 with open(file_path, "w", encoding="utf-8") as f:
-                    f.write(output_html)
+                    f.write(output)
 
             if getattr(settings, "PYINSTRUMENT_URL_ARGUMENT", "profile") in request.GET:
-                return HttpResponse(output_html)
+                if isinstance(renderer, HTMLRenderer):
+                    return HttpResponse(output)
+                else:
+                    renderer = HTMLRenderer()
+                    output = renderer.render(profile_session)
+                    return HttpResponse(output)
             else:
                 return response
         else:

pyinstrument/renderers/base.py

@@ -29,6 +29,10 @@ class Renderer:
     Dictionary containing processor options, passed to each processor.
     """
 
+    output_file_extension: str = "txt"
+    """Renderer output file extension with out dot prefix. The default value is `txt`
+    """
+
     def __init__(
         self,
         show_all: bool = False,

pyinstrument/renderers/html.py

@@ -20,6 +20,8 @@ class HTMLRenderer(Renderer):
     Renders a rich, interactive web page, as a string of HTML.
     """
 
+    output_file_extension = "html"
+
     def __init__(self, **kwargs: Any):
         super().__init__(**kwargs)
 

pyinstrument/renderers/jsonrenderer.py

@@ -25,6 +25,8 @@ class JSONRenderer(Renderer):
     Outputs a tree of JSON, containing processed frames.
     """
 
+    output_file_extension = "json"
+
     def __init__(self, **kwargs: Any):
         super().__init__(**kwargs)