@zlooun/exceljs
Version:
Fixes the problem with writing a file using streams and not using RAM based on 'exeljs'
145 lines (142 loc) • 5.66 kB
JavaScript
"use strict";
function _typeof(obj) { "@babel/helpers - typeof"; return _typeof = "function" == typeof Symbol && "symbol" == typeof Symbol.iterator ? function (obj) { return typeof obj; } : function (obj) { return obj && "function" == typeof Symbol && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }, _typeof(obj); }
function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, _toPropertyKey(descriptor.key), descriptor); } }
function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); Object.defineProperty(Constructor, "prototype", { writable: false }); return Constructor; }
function _toPropertyKey(arg) { var key = _toPrimitive(arg, "string"); return _typeof(key) === "symbol" ? key : String(key); }
function _toPrimitive(input, hint) { if (_typeof(input) !== "object" || input === null) return input; var prim = input[Symbol.toPrimitive]; if (prim !== undefined) { var res = prim.call(input, hint || "default"); if (_typeof(res) !== "object") return res; throw new TypeError("@@toPrimitive must return a primitive value."); } return (hint === "string" ? String : Number)(input); }
// =======================================================================================================
// StreamConverter
//
// convert between encoding schemes in a stream
// Work in Progress - Will complete this at some point
var jconv;
var StreamConverter = /*#__PURE__*/function () {
function StreamConverter(inner, options) {
_classCallCheck(this, StreamConverter);
this.inner = inner;
options = options || {};
this.innerEncoding = (options.innerEncoding || 'UTF8').toUpperCase();
this.outerEncoding = (options.outerEncoding || 'UTF8').toUpperCase();
this.innerBOM = options.innerBOM || null;
this.outerBOM = options.outerBOM || null;
this.writeStarted = false;
}
_createClass(StreamConverter, [{
key: "convertInwards",
value: function convertInwards(data) {
if (data) {
if (typeof data === 'string') {
data = Buffer.from(data, this.outerEncoding);
}
if (this.innerEncoding !== this.outerEncoding) {
data = jconv.convert(data, this.outerEncoding, this.innerEncoding);
}
}
return data;
}
}, {
key: "convertOutwards",
value: function convertOutwards(data) {
if (typeof data === 'string') {
data = Buffer.from(data, this.innerEncoding);
}
if (this.innerEncoding !== this.outerEncoding) {
data = jconv.convert(data, this.innerEncoding, this.outerEncoding);
}
return data;
}
}, {
key: "addListener",
value: function addListener(event, handler) {
this.inner.addListener(event, handler);
}
}, {
key: "removeListener",
value: function removeListener(event, handler) {
this.inner.removeListener(event, handler);
}
}, {
key: "write",
value: function write(data, encoding, callback) {
if (encoding instanceof Function) {
callback = encoding;
encoding = undefined;
}
if (!this.writeStarted) {
// if inner encoding has BOM, write it now
if (this.innerBOM) {
this.inner.write(this.innerBOM);
}
// if outer encoding has BOM, delete it now
if (this.outerBOM) {
if (data.length <= this.outerBOM.length) {
if (callback) {
callback();
}
return;
}
var bomless = Buffer.alloc(data.length - this.outerBOM.length);
data.copy(bomless, 0, this.outerBOM.length, data.length);
data = bomless;
}
this.writeStarted = true;
}
this.inner.write(this.convertInwards(data), encoding ? this.innerEncoding : undefined, callback);
}
}, {
key: "read",
value: function read() {
// TBD
}
}, {
key: "pipe",
value: function pipe(destination, options) {
var reverseConverter = new StreamConverter(destination, {
innerEncoding: this.outerEncoding,
outerEncoding: this.innerEncoding,
innerBOM: this.outerBOM,
outerBOM: this.innerBOM
});
this.inner.pipe(reverseConverter, options);
}
}, {
key: "close",
value: function close() {
this.inner.close();
}
}, {
key: "on",
value: function on(type, callback) {
var _this = this;
switch (type) {
case 'data':
this.inner.on('data', function (chunk) {
callback(_this.convertOutwards(chunk));
});
return this;
default:
this.inner.on(type, callback);
return this;
}
}
}, {
key: "once",
value: function once(type, callback) {
this.inner.once(type, callback);
}
}, {
key: "end",
value: function end(chunk, encoding, callback) {
this.inner.end(this.convertInwards(chunk), this.innerEncoding, callback);
}
}, {
key: "emit",
value: function emit(type, value) {
this.inner.emit(type, value);
}
}]);
return StreamConverter;
}();
module.exports = StreamConverter;
//# sourceMappingURL=stream-converter.js.map