Loading local soundFont file

[marriusco]

Am I doing it right.

I am trying to open a local sound font file. It looks like is not being applied.
I will step trough the code anyway but I am asking first.

   var t = this;
      var a = document.createElement("input");

      a.type = "file", a.accept = ".sf2", a.onchange = function() {
           1 === a.files.length && a.openFile(a.files[0]);
      }, document.body.appendChild(a),
         a.click(),
         document.body.removeChild(a),
         a.openFile=function(e){
            a = new FileReader;
            a.onload=function(e){
                var mob = $("#mobile").length;
                const bytes = new Uint8Array([0]);
                api.settings.player.soundFont = bytes;
//                api.loadSoundFont(bytes); 

                api.updateSettings();
                api.render();
            };
            a.readAsArrayBuffer(e);
        }

[Danielku15]

There are quite some risky and problematic things in your code you likely need to clean:

• Reusing a for the link and later for the FileReader is risky.
• const bytes = new Uint8Array([0]); is wrong. You are creating here a new byte array with one byte (value=0). You need to access .result of the FileReader to get the read array buffer.
• I think it is also wrong to pass e into readAsArrayBuffer this function needs the Blob or File object which you want to read as buffer. I recommend building first an example where you are sure you have a proper ArrayBuffer or Uint8Array before proceeding with forwarding it to alphaTab. If you have problems there, I recommend StackOverflow to get guidance.
• According to the docs the settings.player.soundFont needs to be a URL. It will not work. But your commented approach should work then as loadSoundFont supports bytes. It's a bit an inconvenience which I might consider to improve that also ArrayBuffer or Uint8Array can be directly set on the player.soundFont settings object.

[marriusco]

Hi,
Thank for the prompt response. Yes I noticed that. I used a function I had before to open local tabs,
and I paste it and mess it up. [0].. where it came from ?
I am not a JS guy at all, but... Is fixed and works fine. Here is the final version for reference.

function open_local_sf(api)
{
      var t = this;
      var a = document.createElement("input");

      a.type = "file", a.accept = ".sf2", a.onchange = function() {
           1 === a.files.length && a.openFile(a.files[0]);
      }, document.body.appendChild(a),
         a.click(),
         document.body.removeChild(a),
         a.openFile=function(e){
            a = new FileReader;
            a.onload=function(e){
                const bytes = new Uint8Array(e.target.result);
                api.loadSoundFont(bytes);
                api.render();
            };
            a.readAsArrayBuffer(e);
        }
}