hide ugliness of tile url function

We basically do the same hacky trick in two different places, so maybe
we should put it into a separate function, test it, and if a better
implementation arises, swap it.

4 files changed, 42 insertions, 28 deletions

diff --git a/fietsboek/jinja2.py b/fietsboek/jinja2.py
index a3ca7d8..f5ae7d7 100644
--- a/fietsboek/jinja2.py
+++ b/fietsboek/jinja2.py
@@ -9,6 +9,8 @@ from jinja2.runtime import Context
 from markupsafe import Markup
 from pyramid.request import Request
 
+from . import util
+
 
 @jinja2.pass_context
 def filter_format_decimal(ctx: Context, value: float) -> str:
@@ -94,12 +96,7 @@ def global_embed_tile_layers(request: Request) -> Markup:
     else:
 
         def _url(source):
-            return (
-                request.route_url("tile-proxy", provider=source.layer_id, x="{x}", y="{y}", z="{z}")
-                .replace("%7Bx%7D", "{x}")
-                .replace("%7By%7D", "{y}")
-                .replace("%7Bz%7D", "{z}")
-            )
+            return util.tile_url(request, "tile-proxy", provider=source.layer_id)
 
     return Markup(
         json.dumps(
diff --git a/fietsboek/util.py b/fietsboek/util.py
index d6d0aea..c507cf1 100644
--- a/fietsboek/util.py
+++ b/fietsboek/util.py
@@ -322,6 +322,33 @@ def read_localized_resource(
     return f"{locale_name}:{path}"
 
 
+def tile_url(request: Request, route_name: str, **kwargs: str) -> str:
+    """Generates a URL for tiles.
+
+    This is basically :meth:`request.route_url`, but it keeps the
+    ``{x}``/``{y}``/``{z}`` placeholders intact for consumption by Leaflet.
+
+    Expects that the URL takes a ``x``, ``y`` and ``z`` parameter.
+
+    :param request: The Pyramid request.
+    :param route_name: The name of the route.
+    :param kwargs: Remaining route parameters. Will be passed to ``route_url``.
+    :return: The route URL, with intact placeholders.
+    """
+    # This feels hacky (because it is), but I don't see a better way. The route
+    # generation is basically a closure that fills the placeholders
+    # all-or-none, and there is no way to get a "structured" representation of
+    # the URL without re-parsing it.
+    # Using {x} triggers the urlquoting, so we need to do some .replace() calls
+    # in the end anyway. Might as well use something that looks a bit better,
+    # and not %7Bx%7D.
+    kwargs["x"] = "__x__"
+    kwargs["y"] = "__y__"
+    kwargs["z"] = "__z__"
+    route = request.route_url(route_name, **kwargs)
+    return route.replace("__x__", "{x}").replace("__y__", "{y}").replace("__z__", "{z}")
+
+
 def secure_filename(filename: str) -> str:
     r"""Pass it a filename and it will return a secure version of it.  This
     filename can then safely be stored on a regular file system and passed
diff --git a/fietsboek/views/profile.py b/fietsboek/views/profile.py
index 9f68d2f..4d23ae4 100644
--- a/fietsboek/views/profile.py
+++ b/fietsboek/views/profile.py
@@ -132,6 +132,7 @@ def profile(request: Request) -> dict:
     total.moving_time = round_to_seconds(total.moving_time)
     total.stopped_time = round_to_seconds(total.stopped_time)
 
+    user_id = request.context.id
     heatmap_url = None
     tilehunt_url = None
     try:
@@ -140,29 +141,9 @@ def profile(request: Request) -> dict:
         pass
     else:
         if user_dir.heatmap_path().is_file():
-            heatmap_url = request.route_url(
-                "user-tile",
-                user_id=request.context.id,
-                map="heatmap",
-                z="ZZZ",
-                x="XXX",
-                y="YYY",
-            )
-            heatmap_url = (
-                heatmap_url.replace("ZZZ", "{z}").replace("XXX", "{x}").replace("YYY", "{y}")
-            )
+            heatmap_url = util.tile_url(request, "user-tile", user_id=user_id, map="heatmap")
         if user_dir.tilehunt_path().is_file():
-            tilehunt_url = request.route_url(
-                "user-tile",
-                user_id=request.context.id,
-                map="tilehunt",
-                z="ZZZ",
-                x="XXX",
-                y="YYY",
-            )
-            tilehunt_url = (
-                tilehunt_url.replace("ZZZ", "{z}").replace("XXX", "{x}").replace("YYY", "{y}")
-            )
+            tilehunt_url = util.tile_url(request, "user-tile", user_id=user_id, map="tilehunt")
 
     return {
         "user": request.context,
diff --git a/tests/unit/test_util.py b/tests/unit/test_util.py
index b35f218..949acb5 100644
--- a/tests/unit/test_util.py
+++ b/tests/unit/test_util.py
@@ -82,3 +82,12 @@ def test_tour_metadata(gpx_file):
 @pytest.mark.parametrize('mps, kph', [(1, 3.6), (10, 36)])
 def test_mps_to_kph(mps, kph):
     assert util.mps_to_kph(mps) == pytest.approx(kph, 0.1)
+
+
+def test_tile_url(app_request):
+    route_url = util.tile_url(app_request, "tile-proxy", provider="bobby")
+
+    assert "{x}" in route_url
+    assert "{y}" in route_url
+    assert "{z}" in route_url
+    assert "bobby" in route_url