[dart-misc] How do I url-encode in Dart in the format that the Twitter API expects?

[Danny Tuppeny]

(Also on StackOverflow if that's your thing
<http://stackoverflow.com/q/38526408/25124>...)

I wrote some code
<https://blog.dantup.com/2016/07/simplest-csharp-code-to-post-a-tweet-using-oauth/> to
post tweets in C#. One of the things that tripped me up was the
url-encoding of data since there seemed to be many options:


var input = "Hello Ladies + Gentlemen, a signed OAuth request!";var expected = "Hello%20Ladies%20%2B%20Gentlemen%2C%20a%20signed%20OAuth%20request%21";
Console.WriteLine(WebUtility.UrlEncode(input) == expected); // FalseConsole.WriteLine(Uri.EscapeUriString(input) == expected); // FalseConsole.WriteLine(Uri.EscapeDataString(input) == expected); // True


I'm now trying to do the same thing in Dart. I've tried all the encode
methods in the Uri class, but none seem to output the same.


Code: (DartPad
<https://dartpad.dartlang.org/a8874dae0de40be353dace32512becfc>)

print(Uri.encodeQueryComponent("Hello Ladies + Gentlemen, a signed OAuth request!"));
print(Uri.encodeFull("Hello Ladies + Gentlemen, a signed OAuth request!"));
print(Uri.encodeComponent("Hello Ladies + Gentlemen, a signed OAuth request!"));


Output:

Hello+Ladies+%2B+Gentlemen%2C+a+signed+OAuth+request%21Hello%20Ladies%20+%20Gentlemen,%20a%20signed%20OAuth%20request!Hello%20Ladies%20%2B%20Gentlemen%2C%20a%20signed%20OAuth%20request!


The last one (encodeComponent) seems the closest, just the exclamation mark
is wrong.


Is there an existing method that does this encoding as I require (the same
as C#'s EscapeDataString)?