JavaScript - convert blob to text (from UTF-8 bytes)

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function readText(blob, callback) {
    if (window.FileReader) {
        var reader = new FileReader();
        reader.onload = function() {
            callback(reader.result, null);
        };
        reader.onerror = function() {
            callback(null, 'Incorrect blob or file object.');
        };
        reader.readAsText(blob, 'UTF-8');
    } else {
        callback(null, 'File API is not supported.');
    }
}


// Usage example:

const blob = ...  // Hint: File is Blob so we can convert read file as text.

readText(blob, function(text, error) {
    if (!error) {
        // Put `text` variable usage here ...
    }
});


// See also:
//
//     1. https://dirask.com/snippets/JavaScript-convert-text-to-Blob-text-plain-and-UTF-8-encoding-DlBN4j