I am puzzled by how they actually encoded the PNG as a String, I tried a couple of alternatives but I could not get binary data out of it so that it parsed successfully as PNG.
If I would have to encode binary data in JSON I would use Base64 encoding (but alternatives exist). > On 24 Apr 2017, at 20:36, Juraj Kubelka <juraj.kube...@icloud.com> wrote: > > Hi, > > I was playing with GitHub Gist API and I have queried the following Gist: > https://gist.github.com/mbostock/5503544 > I was interested how the PNG image is returned: > https://gist.github.com/mbostock/5503544#file-thumbnail-png > > I can obtain the whole Gist executing: > > STONJSON fromString: > (ZnClient new > url: 'https://api.github.com/gists/5503544'; > accept: 'application/vnd.github.v3+json'; > get). > > I can get PNG contents executing: > > pngData := (ZnEasy get: > ((((STONJSON fromString: > (ZnClient new > url: 'https://api.github.com/gists/5503544'; > accept: 'application/vnd.github.v3+json'; > get)) at: 'files') at: 'thumbnail.png') at: 'raw_url')) > contents. > PNGReadWriter formFromStream: rawPng readStream. > > But the PNG image is part of the Gist query and can be retrieved by: > > pngContent := ((((STONJSON fromString: > (ZnClient new > url: 'https://api.github.com/gists/5503544'; > accept: 'application/vnd.github.v3+json'; > get)) at: 'files') at: 'thumbnail.png') at: 'content'). > > "As pngContent is a WideString, I cannot use:" > PNGReadWriter formFromStream: pngContent readStream. > > How can I read the PNG image from the pngContent? Any idea? > And the reverse question: How can I send the PNG bytes using JSON format? > > Thanks! > Juraj >
