Implement FileReader.readAsArrayBuffer
Smarticles101 opened this issue · comments
Description
FileReader.readAsArrayBuffer
is not implemented.
Reproducible Demo
https://github.com/facebook/react-native/blob/master/Libraries/Blob/FileReader.js#L83-L85
I plan on working towards implementing this if approved.
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Hi! I need readAsArrayBuffer implementation too, is there any workaround to use this with expo? I'm using expo to avoid using a mac in the development process.
Thanks!
Hello,
I manage to make it work by using readAsDataURL
:
FileReader.prototype.readAsArrayBuffer = function (blob) {
if (this.readyState === this.LOADING) throw new Error("InvalidStateError");
this._setReadyState(this.LOADING);
this._result = null;
this._error = null;
const fr = new FileReader();
fr.onloadend = () => {
const content = atob(fr.result.substr("data:application/octet-stream;base64,".length));
const buffer = new ArrayBuffer(content.length);
const view = new Uint8Array(buffer);
view.set(Array.from(content).map(c => c.charCodeAt(0)));
this._result = buffer;
this._setReadyState(this.DONE);
};
fr.readAsDataURL(blob);
}
// from: https://stackoverflow.com/questions/42829838/react-native-atob-btoa-not-working-without-remote-js-debugging
const chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=';
const atob = (input = '') => {
let str = input.replace(/=+$/, '');
let output = '';
if (str.length % 4 == 1) {
throw new Error("'atob' failed: The string to be decoded is not correctly encoded.");
}
for (let bc = 0, bs = 0, buffer, i = 0;
buffer = str.charAt(i++);
~buffer && (bs = bc % 4 ? bs * 64 + buffer : buffer,
bc++ % 4) ? output += String.fromCharCode(255 & bs >> (-2 * bc & 6)) : 0
) {
buffer = chars.indexOf(buffer);
}
return output;
}
Is there a way to re-open this issue or do we have to create a new issue?