Class UriPatcher

Workarounds for some unfortunate behaviors in the .NET Framework's implementation of System.Uri

Inheritance
object
UriPatcher
Inherited Members
Namespace: Google.Apis.Util
Assembly: Google.Apis.Core.dll
Syntax
public static class UriPatcher
Remarks

UriPatcher lets us work around some unfortunate behaviors in the .NET Framework's implementation of System.Uri.

== Problem 1: Slashes and dots

Prior to .NET 4.5, System.Uri would always unescape "%2f" ("/") and "%5c" ("\"). Relative path components were also compressed.

As a result, this: "http://www.example.com/.%2f.%5c./" ... turned into this: "http://www.example.com/"

This breaks API requests where slashes or dots appear in path parameters. Such requests arise, for example, when these characters appear in the name of a GCS object.

== Problem 2: Fewer unreserved characters

Unless IDN/IRI parsing is enabled -- which it is not, by default, prior to .NET 4.5 -- Uri.EscapeDataString uses the set of "unreserved" characters from RFC 2396 instead of the newer, smaller list from RFC 3986. We build requests using URI templating as described by RFC 6570, which specifies that the latter definition (RFC 3986) should be used.

This breaks API requests with parameters including any of: !*'()

== Solutions

Though the default behaviors changed in .NET 4.5, these "quirks" remain for compatibility unless the application explicitly targets the new runtime. Usually, that means adding a TargetFrameworkAttribute to the entry assembly.

Applications running on .NET 4.0 or later can also set "DontUnescapePathDotsAndSlashes" and enable IDN/IRI parsing using app.config or web.config.

As a class library, we can't control app.config or the entry assembly, so we can't take either approach. Instead, we resort to reflection trickery to try to solve these problems if we detect they exist. Sorry.

Methods

PatchUriQuirks()

Patch URI quirks in System.Uri. See class summary for details.

Declaration
public static void PatchUriQuirks()