Enable server to alternatively output response ctx as JSON, for debugging and testing...

[plomtask] / plomtask / http.py

diff --git a/plomtask/http.py b/plomtask/http.py
index 26c8b719fec481e4106d66073a85844a1d16491a..d602f07b9baf3c18df19fa88435928d2a33845d6 100644 (file)
--- a/plomtask/http.py
+++ b/plomtask/http.py
@@ -1,11 +1,12 @@
 """Web server stuff."""
 from __future__ import annotations
 from dataclasses import dataclass
-from typing import Any, Callable, Mapping
+from typing import Any, Callable
 from base64 import b64encode, b64decode
 from http.server import BaseHTTPRequestHandler
 from http.server import HTTPServer
 from urllib.parse import urlparse, parse_qs
+from json import dumps as json_dumps
 from os.path import split as path_split
 from jinja2 import Environment as JinjaEnv, FileSystemLoader as JinjaFSLoader
 from plomtask.dating import date_in_n_days
@@ -16,6 +17,7 @@ from plomtask.db import DatabaseConnection, DatabaseFile
 from plomtask.processes import Process, ProcessStep, ProcessStepsNode
 from plomtask.conditions import Condition
 from plomtask.todos import Todo
+from plomtask.db import BaseModel
 
 TEMPLATES_DIR = 'templates'
 
@@ -27,7 +29,37 @@ class TaskServer(HTTPServer):
                  *args: Any, **kwargs: Any) -> None:
         super().__init__(*args, **kwargs)
         self.db = db_file
-        self.jinja = JinjaEnv(loader=JinjaFSLoader(TEMPLATES_DIR))
+        self.headers: list[tuple[str, str]] = []
+        self._render_mode = 'html'
+        self._jinja = JinjaEnv(loader=JinjaFSLoader(TEMPLATES_DIR))
+
+    def set_json_mode(self) -> None:
+        """Make server send JSON instead of HTML responses."""
+        self._render_mode = 'json'
+        self.headers += [('Content-Type', 'application/json')]
+
+    @staticmethod
+    def ctx_to_json(ctx: dict[str, object]) -> str:
+        """Render ctx into JSON string."""
+        def walk_ctx(node: object) -> Any:
+            if isinstance(node, BaseModel):
+                return node.as_dict
+            if isinstance(node, (list, tuple)):
+                return [walk_ctx(x) for x in node]
+            if isinstance(node, HandledException):
+                return str(node)
+            return node
+        for k, v in ctx.items():
+            ctx[k] = walk_ctx(v)
+        return json_dumps(ctx)
+
+    def render(self, ctx: dict[str, object], tmpl_name: str = '') -> str:
+        """Render ctx according to self._render_mode.."""
+        tmpl_name = f'{tmpl_name}.{self._render_mode}'
+        if 'html' == self._render_mode:
+            template = self._jinja.get_template(tmpl_name)
+            return template.render(ctx)
+        return self.__class__.ctx_to_json(ctx)
 
 
 class InputsParser:
@@ -106,16 +138,18 @@ class TaskHandler(BaseHTTPRequestHandler):
     _form_data: InputsParser
     _params: InputsParser
 
-    def _send_html(self,
+    def _send_page(self,
+                   ctx: dict[str, Any],
                    tmpl_name: str,
-                   ctx: Mapping[str, object],
-                   code: int = 200) -> None:
+                   code: int = 200
+                   ) -> None:
         """Send HTML as proper HTTP response."""
-        tmpl = self.server.jinja.get_template(tmpl_name)
-        html = tmpl.render(ctx)
+        body = self.server.render(ctx, tmpl_name)
         self.send_response(code)
+        for header_tuple in self.server.headers:
+            self.send_header(*header_tuple)
         self.end_headers()
-        self.wfile.write(bytes(html, 'utf-8'))
+        self.wfile.write(bytes(body, 'utf-8'))
 
     @staticmethod
     def _request_wrapper(http_method: str, not_found_msg: str
@@ -148,7 +182,7 @@ class TaskHandler(BaseHTTPRequestHandler):
                         assert hasattr(cls, 'empty_cache')
                         cls.empty_cache()
                     ctx = {'msg': error}
-                    self._send_html('msg.html', ctx, error.http_code)
+                    self._send_page(ctx, 'msg', error.http_code)
                 finally:
                     self.conn.close()
             return wrapper
@@ -158,11 +192,11 @@ class TaskHandler(BaseHTTPRequestHandler):
     def do_GET(self, handler: Callable[[], str | dict[str, object]]
                ) -> str | None:
         """Render page with result of handler, or redirect if result is str."""
-        tmpl_name = f'{self._site}.html'
-        ctx_or_redir = handler()
-        if isinstance(ctx_or_redir, str):
-            return ctx_or_redir
-        self._send_html(tmpl_name, ctx_or_redir)
+        tmpl_name = f'{self._site}'
+        ctx_or_redir_target = handler()
+        if isinstance(ctx_or_redir_target, str):
+            return ctx_or_redir_target
+        self._send_page(ctx_or_redir_target, tmpl_name)
         return None
 
     @_request_wrapper('POST', 'Unknown POST target')