const { PACKET_TYPES } = require("./commons"); const withNativeBlob = typeof Blob === "function" || (typeof Blob !== "undefined" && Object.prototype.toString.call(Blob) === "[object BlobConstructor]"); const withNativeArrayBuffer = typeof ArrayBuffer === "function"; // ArrayBuffer.isView method is not defined in IE10 const isView = obj => { return typeof ArrayBuffer.isView === "function" ? ArrayBuffer.isView(obj) : obj && obj.buffer instanceof ArrayBuffer; }; const encodePacket = ({ type, data }, supportsBinary, callback) => { if (withNativeBlob && data instanceof Blob) { if (supportsBinary) { return callback(data); } else { return encodeBlobAsBase64(data, callback); } } else if ( withNativeArrayBuffer && (data instanceof ArrayBuffer || isView(data)) ) { if (supportsBinary) { return callback(data); } else { return encodeBlobAsBase64(new Blob([data]), callback); } } // plain string return callback(PACKET_TYPES[type] + (data || "")); }; const encodeBlobAsBase64 = (data, callback) => { const fileReader = new FileReader(); fileReader.onload = function() { const content = fileReader.result.split(",")[1]; callback("b" + content); }; return fileReader.readAsDataURL(data); }; module.exports = encodePacket;