datasette.urls methods will not apply base_url prefix twice, refs #1026

datasette/url_builder.py

@@ -1,4 +1,4 @@
-from .utils import path_with_format, HASH_LENGTH
+from .utils import path_with_format, HASH_LENGTH, PrefixedUrlString
 import urllib
 
 
@@ -7,12 +7,13 @@ class Urls:
         self.ds = ds
 
     def path(self, path, format=None):
-        if path.startswith("/"):
-            path = path[1:]
-        path = self.ds.config("base_url") + path
+        if not isinstance(path, PrefixedUrlString):
+            if path.startswith("/"):
+                path = path[1:]
+            path = self.ds.config("base_url") + path
         if format is not None:
             path = path_with_format(path=path, format=format)
-        return path
+        return PrefixedUrlString(path)
 
     def instance(self, format=None):
         return self.path("", format=format)
@@ -40,19 +41,19 @@ class Urls:
         path = "{}/{}".format(self.database(database), urllib.parse.quote_plus(table))
         if format is not None:
             path = path_with_format(path=path, format=format)
-        return path
+        return PrefixedUrlString(path)
 
     def query(self, database, query, format=None):
         path = "{}/{}".format(self.database(database), urllib.parse.quote_plus(query))
         if format is not None:
             path = path_with_format(path=path, format=format)
-        return path
+        return PrefixedUrlString(path)
 
     def row(self, database, table, row_path, format=None):
         path = "{}/{}".format(self.table(database, table), row_path)
         if format is not None:
             path = path_with_format(path=path, format=format)
-        return path
+        return PrefixedUrlString(path)
 
     def row_blob(self, database, table, row_path, column):
         return self.table(database, table) + "/{}.blob?_blob_column={}".format(

datasette/utils/__init__.py

@@ -1010,3 +1010,26 @@ async def initial_path_for_datasette(datasette):
     else:
         path = datasette.urls.instance()
     return path
+
+
+class PrefixedUrlString(str):
+    def __add__(self, other):
+        return type(self)(super().__add__(other))
+
+    def __getattribute__(self, name):
+        if name in dir(str):
+
+            def method(self, *args, **kwargs):
+                value = getattr(super(), name)(*args, **kwargs)
+                if isinstance(value, str):
+                    return type(self)(value)
+                elif isinstance(value, list):
+                    return [type(self)(i) for i in value]
+                elif isinstance(value, tuple):
+                    return tuple(type(self)(i) for i in value)
+                else:
+                    return value
+
+            return method.__get__(self)
+        else:
+            return super().__getattribute__(name)