Unable to determine a compatible waveformData format

[Grumpier]

I'm trying to serve a precomputed json waveform to Peaks.init using the waveformData option and get the above error message. i have no problem if I use dataUri to point to the same file on the server. Here's my code:

      const track_id = document.getElementById("track_id").dataset.id;
      async function getJson() {
        const wave = await fetch(${origin}/wave/${track_id});
        return wave.json();
      }
    
      (async function(Peaks) {
        const wave = await getJson();
        console.log(wave);
        var options = {
          containers: {
            zoomview: document.getElementById('zoomview-container'),
            overview: document.getElementById('overview-container') },
          zoomview: {waveformColor: 'rgba(0, 0, 255, 1)'},
          mediaElement: document.getElementById('audio'),
          waveformData: { json: wave },
          keyboard: true,
          pointMarkerColor: '#006eb0',
          showPlayheadTime: true,
          emitCueEvents: true
        };

Here's what the console.log of the waveform looks like:

Any ideas of what I'm doing wrong? Thanks!

[chrisn]

I don't see anything immediately wrong. The code that produces the error is here, does that suggest anything?

[Grumpier]

Thanks chrisn. This helped. The isObject(waveformData.json) test is failing because the wave value I am passing to options is apparently still wrapped in a promise. It's odd, because console.log(options.waveformData.json) properly displays it as a json object. I've tried wrapping all of the peaks function inside of getJson().then, since I thought the promise should then be unwrapped, but it still fails. I'm not a strong enough JS programmer to know exactly how to resolve this. Do you have any suggestion?

[chrisn]

I can only think that there's some difference between the code you posted here and what is in your project.

Because you're using const wave = await getJson(); then wave will contain the data after the promise resolves.

If options.waveformData.json were a promise, you would see a different error: WaveformData.create(): Unknown data format

[Grumpier]

You're right! The promise is being resolved. The problem was at the server end. I was using

fs.readFile( fileName, "utf-8", function(err, data) { res.json(data) })

which fails. I switched to a simple

res.sendFile (fileName)

and it now works. Thanks for your help!

[chrisn]

Thanks! It sounds like the data was being stringified as JSON too many times.