Make audio clip from DataURL

Cocos Creator
#1

in my case I want to play MP3 file by just drag and drop the file on Cocos Canvas.
after drop we can read file in various data type, for me i choose DataURL.
now i really can’t make clip by the read data.
here the existing code that doesn’t work:

let reader = new FileReader()
reader.onload = (data) => {
    let result = data.target.result
    cc.loader.load(result, (err, res) => {
        if (!err) {
            // don't know how to make make clip by res
            let clip = res
        } else {
            alert(err)
        }
    })
}
reader.readAsDataURL(file)

is there anyone ever try the case?
please give me the advise, thanks

#2

solved it by using ArrayBuffer instead

let reader = new FileReader()
reader.onload = (data) => {
    let result = data.target.result
    window.AudioContext = window.AudioContext || window.webkitAudioContext
    let context = new AudioContext()
    context.decodeAudioData(result, (buffer) => {
        audioSource.audio.mount(buffer)
    }, (error) => {
        console.log(error)
    })
}
reader.readAsArrayBuffer(file)