Wrong/missing charset on JSON response

[FabulousGee]

I had some issues with Umlauts and so I double-checked everything on my side. All fine.
But when I checked the header-handling in atk I found a possible bug. When I set the charset on termination myself, it gets omitted.

I use the following line of code to output my JSON:

$this->_app->terminate(json_encode($data), ['Cache-Control' => 'no-transform,public,max-age=300,s-maxage=900', 'content-type' => 'application/json; charset=utf-8', 'Status' => ''.$code]);

Note the "charset=utf-8" to set the encoding (which should be standard on JSON but isn't necessary to set by HTTP guidelines)

When I now look at \atk4\ui\src\App.php I saw the content-type being hardcoded:

private function outputResponseJson($data, array $headers = []): void
    {
        if (!is_string($data)) {
            $data = $this->encodeJson($data);
        }
        $this->outputResponse(
            $data,
            array_merge($this->normalizeHeaders($headers), ['content-type' => 'application/json'])
        );
    }

I think it should be considered to either hardcode it to "['content-type' => 'application/json; charset=utf-8']" or check the original content-type more properly and reapply any attached strings again

[FabulousGee]

@DarkSide666 @mvorisek regarding the discussion on my pull request, I want to continue the discussion about it here. The PR was just my first idea, I am sure there could be a better way. For example it would suffice to check, if the content-type has already been set and just skip it then (to let the user override it if they want to)

I am not into all of these things really, but I read a lot about it the last days and e.g. in this StackOverflow thread they mention that the charset (encoding) isn't implied as a default but furthermore should always be explicitely stated.
Also, there is a deeper conversation with some serious sources (like some HTTP specs) about the topic on the libraries page on GitHub as well: dart-lang/http#175 (comment)

So I still think a change on atk side should really be considered, no matter which way is preferred

[mvorisek]

Which browser/client does detect the encoding wrongly?

PS: your PR is for JSON mime, which should be defaulted to UTF-8. HTML5 has UTF-8 encoding as default too.

[FabulousGee]

It's the HTTP library which I use in dart (Flutter) - I linked the issue above. Did you read through the post on their tracker? They describe very well which defaults apply and which do not.

I really understand your point, it doesn't seem necessary to set something which should be considered as default but actually it isn't (as described here )

And even if you insist on this being default behaviour, I don't agree with the way it's handled on atk4.
If I want to set my own charset, I am currently not able to do it in combination with the JSON output. If you take my first post again, IMHO the termination should use the charset I provide and not just delete my settings (that's how it's handled currently!)

[mvorisek]

You can extend App class and override the output/normalize headers method.

For me, it looks like an issue in Dart/Flutter. If you think is should be fixed in atk, please provide some data from major API libs/providers.