Add sub-app to generate open api spec

aiohttp_pydantic/oas/view.py

@@ -0,0 +1,85 @@
+from aiohttp.web import json_response, Response
+
+from aiohttp_pydantic.oas.struct import OpenApiSpec3, OperationObject, PathItem
+from typing import Type
+
+from ..injectors import _parse_func_signature
+from ..view import PydanticView, is_pydantic_view
+
+
+JSON_SCHEMA_TYPES = {float: "number", str: "string", int: "integer"}
+
+
+def _add_http_method_to_oas(oas_path: PathItem, method: str, view: Type[PydanticView]):
+    method = method.lower()
+    mtd: OperationObject = getattr(oas_path, method)
+    handler = getattr(view, method)
+    path_args, body_args, qs_args, header_args = _parse_func_signature(handler)
+
+    if body_args:
+        mtd.request_body.content = {
+            "application/json": {"schema": next(iter(body_args.values())).schema()}
+        }
+
+    i = 0
+    for i, (name, type_) in enumerate(path_args.items()):
+        mtd.parameters[i].required = True
+        mtd.parameters[i].in_ = "path"
+        mtd.parameters[i].name = name
+        mtd.parameters[i].schema = {"type": JSON_SCHEMA_TYPES[type_]}
+
+    for i, (name, type_) in enumerate(qs_args.items(), i + 1):
+        mtd.parameters[i].required = False
+        mtd.parameters[i].in_ = "query"
+        mtd.parameters[i].name = name
+        mtd.parameters[i].schema = {"type": JSON_SCHEMA_TYPES[type_]}
+
+    for i, (name, type_) in enumerate(header_args.items(), i + 1):
+        mtd.parameters[i].required = False
+        mtd.parameters[i].in_ = "header"
+        mtd.parameters[i].name = name
+        mtd.parameters[i].schema = {"type": JSON_SCHEMA_TYPES[type_]}
+
+
+async def get_oas(request):
+    """
+    Generate Open Api Specification from PydanticView in application.
+    """
+    apps = request.app["apps to expose"]
+    oas = OpenApiSpec3()
+    for app in apps:
+        for resources in app.router.resources():
+            for resource_route in resources:
+                if is_pydantic_view(resource_route.handler):
+                    view: Type[PydanticView] = resource_route.handler
+                    info = resource_route.get_info()
+                    path = oas.paths[info.get("path", info.get("formatter"))]
+                    if resource_route.method == "*":
+                        for method_name in view.allowed_methods:
+                            _add_http_method_to_oas(path, method_name, view)
+                    else:
+                        _add_http_method_to_oas(path, resource_route.method, view)
+
+    return json_response(oas.spec)
+
+
+async def oas_ui(request):
+    """
+    View to serve the swagger-ui to read open api specification of application.
+    """
+    template = request.app["index template"]
+
+    static_url = request.app.router["static"].url_for(filename="")
+    spec_url = request.app.router["spec"].url_for()
+    host = request.url.origin()
+
+    return Response(
+        text=template.render(
+            {
+                "openapi_spec_url": host.with_path(str(spec_url)),
+                "static_url": host.with_path(str(static_url)),
+            }
+        ),
+        content_type="text/html",
+        charset="utf-8",
+    )