Add Data Save Functionality

[kylemath]

buttons to save csv files

[korymath]

Here is the easy way to do it:
https://github.com/urish/eeg-explorer/blob/master/src/app/recorder/recorder.component.ts#L41

https://github.com/urish/eeg-explorer/blob/90d5b730a4331dcf40438959a23c7ece99551f04/src/app/recorder/recorder.component.ts#L41

This requires the whole data set to be stored in the browser.

The other option, and the one that might reduce latency, is to publish the data to a Pub/Sub service, or a server that is running to store the data asynchronously from the client code.

Store to bigtable: https://cloud.google.com/bigtable/docs/samples-nodejs-hello

[kylemath]

question becomes, what to record,
then the question becomes, let the user decide,
so have a chart of raw data
then a toggle for filter with input points for cutoffs
they can record at any time and record what is currently being plotted through the pipes

then we have spectra, that is probably a scroll down, but it is useful to watch the spectra and raw data coincidentally and view the changes as filters are introduced,

then the spectra has options to modify the parameters of the fft, and whatever is being shown can be recorded

Then we divide into 5 bins of frequency and show the bar graphs, those can be recorded

lets start with the first one, raw data

[korymath]

I will work on the minimum viable product of a client saving their data in the front end. We do not want to store THIER data on our servers, so we can keep it all client side for now.

[korymath]

Building a csv data array and then downloading with: https://www.npmjs.com/package/react-csv

[korymath]

StreamSaver: https://www.npmjs.com/package/streamsaver

window.onunload = () => {
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  // also possible to call abort on the writer you got from `getWriter()`
  writer.abort()
}
 
window.onbeforeunload = evt => {
  if (!done) {
    evt.returnValue = `Are you sure you want to leave?`;
  }
}

[korymath]

This can be closed with the merging of #77