Predefined queries

[drnextgis]

Hi! Could I ask for guidance regarding the following issue.

By default titiler-pgstac accepts an arbitrary search query for /mosaic/register endpoint but I want to do it more restrictive. Let's assume that for every request based on the information provided inside authorization token we can build our internal SearchQuery object and combine it with the one which is coming from a request using AND clause. Do you think it can be implemented in a general way that other users of titiler-pgstac can benefit from or it is very specific task which requires creation of a tailored application. Thanks!

[vincentsarago]

@drnextgis thanks for opening the discussion.

I don't think there is an easy solution other than for you to re-write https://github.com/stac-utils/titiler-pgstac/blob/master/titiler/pgstac/factory.py#L338-L366

[drnextgis]

I was thinking about something like this:

diff --git a/titiler/pgstac/factory.py b/titiler/pgstac/factory.py
index ac39511..0c54855 100644
--- a/titiler/pgstac/factory.py
+++ b/titiler/pgstac/factory.py
@@ -70,6 +70,8 @@ class MosaicTilerFactory(BaseTilerFactory):
 
     backend_options: Dict = field(default_factory=dict)
 
+    query_factory: Callable[..., SearchQuery] = None
+
     def register_routes(self) -> None:
         """This Method register routes to the router."""
         self._search_routes()
@@ -341,13 +343,18 @@ class MosaicTilerFactory(BaseTilerFactory):
         )
         def register_search(request: Request, body: SearchQuery):
             """Register a Search query."""
-            search = body.json(
+            search = body.dict(
                 exclude_none=True,
                 exclude={"metadata"},
                 by_alias=True,
             )
             metadata = body.metadata or {}
 
+            if self.query_factory is not None:
+                search = self.query_factory(request, search)
+
+            search = json.dumps(search)
+
             with request.app.state.dbpool.connection() as conn:
                 with conn.cursor() as cursor:
                     cursor.execute(

Then user can create custom query_factory function and pass it to MosaicTilerFactory constructor:

diff --git a/titiler/pgstac/main.py b/titiler/pgstac/main.py
index c38f143..6b2aba4 100644
--- a/titiler/pgstac/main.py
+++ b/titiler/pgstac/main.py
@@ -67,7 +67,19 @@ if settings.debug:
 else:
     optional_headers = []
 
-mosaic = MosaicTilerFactory(optional_headers=optional_headers)
+
+def query_factory(request, search):
+    if "filter" in search:
+        search["filter"] = {
+            "op": "and",
+            "args": [
+                {"op": ">", "args": [{"property": "eo:cloud_cover"}, 70]},
+                search["filter"]
+            ]
+        }
+    return search
+
+mosaic = MosaicTilerFactory(optional_headers=optional_headers, query_factory=query_factory)
 app.include_router(mosaic.router)
 
 tms = TMSFactory(supported_tms=TileMatrixSetName, tms_dependency=TMSParams)

[vincentsarago]

looks good to me, I think it will be fine if the factory was search_dependency was set to a default callable like https://github.com/developmentseed/titiler/blob/master/src/titiler/core/titiler/core/factory.py#L123

[drnextgis]

Thank you @vincentsarago! I've made a PR #41.