Can’t report Unicode strings anymore

[tonsky]

I understand it’s because of this commit: 93067d1

I’m positive I’ve reported unicode messages before. What is the motivation behind this change? Why is exception so cryptic (“Dom Error 5” instead of “Can’t report unicode” or something)? What’s the recommended way to convert UTF-8 to ASCII from this point on?

[tonsky]

BTW I believe these lines:

* if (!window.btoa) window.btoa = yellerBase64.encode
* if (!window.atob) window.atob = yellerBase64.decode

Should probably be not in a comment, but in actual code (I think browser-provided atob/btoa are somewhat faster)

[tcrayford]

@tonsky dangit. I'm very sorry this has caused you problems.

That commit was introduced because Yeller was seeing errors where some browsers were sending invalid JSON to Yeller's servers. yeller.js uses a very gnarly transport mechanism - it creates an Image with the json payload as a url attribute. This is the only way (as far as I could tell from my research) of doing cross domain https requests across browsers.

As such all the characters it sends have to be url safe. I'll dig into diagnosing and fixing this, but it's a somewhat nasty problem.

[tonsky]

Hmm, interesting :) Sure, cross-domain requests are hard
JFYI, I patched it by replacing JSON.stringify with code from here: http://stackoverflow.com/a/4901205

function JSON_stringify(s, emit_unicode)
{
   var json = JSON.stringify(s);
   return emit_unicode ? json : json.replace(/[\u007f-\uffff]/g,
      function(c) { 
        return '\\u'+('0000'+c.charCodeAt(0).toString(16)).slice(-4);
      }
   );
}

Quick summary: JSON spec allows for escaping any character with \udddd sequence, which, if enabled, will emit ASCII-safe string for you. Sadly, browser’s JSON.stringify has no option to turn this on (JSON.parse understands it, but you probably don’t need it).

Not sure about its performance though.

[tcrayford]

@tonsky that might work. Performance of the encoding isn't too important for JS clients, the blobs are relatively small most of the time, and it's on the user's side.

[tonsky]

ping