read-blob
Version:
Read file blobs easily
71 lines (58 loc) • 2.21 kB
JavaScript
(function(f){if(typeof exports==="object"&&typeof module!=="undefined"){module.exports=f()}else if(typeof define==="function"&&define.amd){define([],f)}else{var g;if(typeof window!=="undefined"){g=window}else if(typeof global!=="undefined"){g=global}else if(typeof self!=="undefined"){g=self}else{g=this}g.readBlob = f()}})(function(){var define,module,exports;return (function e(t,n,r){function s(o,u){if(!n[o]){if(!t[o]){var a=typeof require=="function"&&require;if(!u&&a)return a(o,!0);if(i)return i(o,!0);var f=new Error("Cannot find module '"+o+"'");throw f.code="MODULE_NOT_FOUND",f}var l=n[o]={exports:{}};t[o][0].call(l.exports,function(e){var n=t[o][1][e];return s(n?n:e)},l,l.exports,e,t,n,r)}return n[o].exports}var i=typeof require=="function"&&require;for(var o=0;o<r.length;o++)s(r[o]);return s})({1:[function(require,module,exports){
/* global FileReader, Blob */
var methods = {
arraybuffer: 'readAsArrayBuffer',
dataurl: 'readAsDataURL',
text: 'readAsText'
};
function readBlob (blob, type, cb) {
var promise;
if (typeof type !== 'string') {
cb = type;
type = 'arraybuffer';
}
if (!(blob instanceof Blob)) {
var err = new Error('first argument is not a blob');
if (cb) {
cb(err);
return;
} else {
return Promise.reject(err);
}
}
if (!cb) {
promise = new Promise(function (resolve, reject) {
cb = function (err, result) {
if (err) reject(err);
else resolve(result);
};
});
}
var method = methods[type.toLowerCase()];
var reader = new FileReader();
reader.addEventListener('loadend', function onend (e) {
reader.removeEventListener('loadend', onend);
if (e.error) {
cb(e.error);
} else {
cb(null, reader.result);
}
});
if (method) {
reader[method](blob);
} else {
// assume the output value is a text encoding
reader.readAsText(blob, type);
}
return promise;
}
module.exports = readBlob;
// add arraybuffer, dataurl, and text methods
// as aliases to their options counterpart
Object.keys(methods).forEach(function (type) {
readBlob[type] = function (blob, cb) {
return readBlob(blob, type, cb);
};
});
},{}]},{},[1])(1)
});