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papaparse.js
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papaparse.js
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/* @license
Papa Parse
v5.3.2
https://github.com/mholt/PapaParse
License: MIT
*/
(function(root, factory)
{
/* globals define */
if (typeof define === 'function' && define.amd)
{
// AMD. Register as an anonymous module.
define([], factory);
}
else if (typeof module === 'object' && typeof exports !== 'undefined')
{
// Node. Does not work with strict CommonJS, but
// only CommonJS-like environments that support module.exports,
// like Node.
module.exports = factory();
}
else
{
// Browser globals (root is window)
root.Papa = factory();
}
// in strict mode we cannot access arguments.callee, so we need a named reference to
// stringify the factory method for the blob worker
// eslint-disable-next-line func-name
}(this, function moduleFactory()
{
'use strict';
var global = (function() {
// alternative method, similar to `Function('return this')()`
// but without using `eval` (which is disabled when
// using Content Security Policy).
if (typeof self !== 'undefined') { return self; }
if (typeof window !== 'undefined') { return window; }
if (typeof global !== 'undefined') { return global; }
// When running tests none of the above have been defined
return {};
})();
function getWorkerBlob() {
var URL = global.URL || global.webkitURL || null;
var code = moduleFactory.toString();
return Papa.BLOB_URL || (Papa.BLOB_URL = URL.createObjectURL(new Blob(["var global = (function() { if (typeof self !== 'undefined') { return self; } if (typeof window !== 'undefined') { return window; } if (typeof global !== 'undefined') { return global; } return {}; })(); global.IS_PAPA_WORKER=true; ", '(', code, ')();'], {type: 'text/javascript'})));
}
var IS_WORKER = !global.document && !!global.postMessage,
IS_PAPA_WORKER = global.IS_PAPA_WORKER || false;
var workers = {}, workerIdCounter = 0;
var Papa = {};
Papa.parse = CsvToJson;
Papa.unparse = JsonToCsv;
Papa.RECORD_SEP = String.fromCharCode(30);
Papa.UNIT_SEP = String.fromCharCode(31);
Papa.BYTE_ORDER_MARK = '\ufeff';
Papa.BAD_DELIMITERS = ['\r', '\n', '"', Papa.BYTE_ORDER_MARK];
Papa.WORKERS_SUPPORTED = !IS_WORKER && !!global.Worker;
Papa.NODE_STREAM_INPUT = 1;
// Configurable chunk sizes for local and remote files, respectively
Papa.LocalChunkSize = 1024 * 1024 * 10; // 10 MB
Papa.RemoteChunkSize = 1024 * 1024 * 5; // 5 MB
Papa.DefaultDelimiter = ','; // Used if not specified and detection fails
// Exposed for testing and development only
Papa.Parser = Parser;
Papa.ParserHandle = ParserHandle;
Papa.NetworkStreamer = NetworkStreamer;
Papa.FileStreamer = FileStreamer;
Papa.StringStreamer = StringStreamer;
Papa.ReadableStreamStreamer = ReadableStreamStreamer;
if (typeof PAPA_BROWSER_CONTEXT === 'undefined') {
Papa.DuplexStreamStreamer = DuplexStreamStreamer;
}
if (global.jQuery)
{
var $ = global.jQuery;
$.fn.parse = function(options)
{
var config = options.config || {};
var queue = [];
this.each(function(idx)
{
var supported = $(this).prop('tagName').toUpperCase() === 'INPUT'
&& $(this).attr('type').toLowerCase() === 'file'
&& global.FileReader;
if (!supported || !this.files || this.files.length === 0)
return true; // continue to next input element
for (var i = 0; i < this.files.length; i++)
{
queue.push({
file: this.files[i],
inputElem: this,
instanceConfig: $.extend({}, config)
});
}
});
parseNextFile(); // begin parsing
return this; // maintains chainability
function parseNextFile()
{
if (queue.length === 0)
{
if (isFunction(options.complete))
options.complete();
return;
}
var f = queue[0];
if (isFunction(options.before))
{
var returned = options.before(f.file, f.inputElem);
if (typeof returned === 'object')
{
if (returned.action === 'abort')
{
error('AbortError', f.file, f.inputElem, returned.reason);
return; // Aborts all queued files immediately
}
else if (returned.action === 'skip')
{
fileComplete(); // parse the next file in the queue, if any
return;
}
else if (typeof returned.config === 'object')
f.instanceConfig = $.extend(f.instanceConfig, returned.config);
}
else if (returned === 'skip')
{
fileComplete(); // parse the next file in the queue, if any
return;
}
}
// Wrap up the user's complete callback, if any, so that ours also gets executed
var userCompleteFunc = f.instanceConfig.complete;
f.instanceConfig.complete = function(results)
{
if (isFunction(userCompleteFunc))
userCompleteFunc(results, f.file, f.inputElem);
fileComplete();
};
Papa.parse(f.file, f.instanceConfig);
}
function error(name, file, elem, reason)
{
if (isFunction(options.error))
options.error({name: name}, file, elem, reason);
}
function fileComplete()
{
queue.splice(0, 1);
parseNextFile();
}
};
}
if (IS_PAPA_WORKER)
{
global.onmessage = workerThreadReceivedMessage;
}
function CsvToJson(_input, _config)
{
_config = _config || {};
var dynamicTyping = _config.dynamicTyping || false;
if (isFunction(dynamicTyping)) {
_config.dynamicTypingFunction = dynamicTyping;
// Will be filled on first row call
dynamicTyping = {};
}
_config.dynamicTyping = dynamicTyping;
_config.transform = isFunction(_config.transform) ? _config.transform : false;
if (_config.worker && Papa.WORKERS_SUPPORTED)
{
var w = newWorker();
w.userStep = _config.step;
w.userChunk = _config.chunk;
w.userComplete = _config.complete;
w.userError = _config.error;
_config.step = isFunction(_config.step);
_config.chunk = isFunction(_config.chunk);
_config.complete = isFunction(_config.complete);
_config.error = isFunction(_config.error);
delete _config.worker; // prevent infinite loop
w.postMessage({
input: _input,
config: _config,
workerId: w.id
});
return;
}
var streamer = null;
if (_input === Papa.NODE_STREAM_INPUT && typeof PAPA_BROWSER_CONTEXT === 'undefined')
{
// create a node Duplex stream for use
// with .pipe
streamer = new DuplexStreamStreamer(_config);
return streamer.getStream();
}
else if (typeof _input === 'string')
{
_input = stripBom(_input);
if (_config.download)
streamer = new NetworkStreamer(_config);
else
streamer = new StringStreamer(_config);
}
else if (_input.readable === true && isFunction(_input.read) && isFunction(_input.on))
{
streamer = new ReadableStreamStreamer(_config);
}
else if ((global.File && _input instanceof File) || _input instanceof Object) // ...Safari. (see issue #106)
streamer = new FileStreamer(_config);
return streamer.stream(_input);
// Strip character from UTF-8 BOM encoded files that cause issue parsing the file
function stripBom(string) {
if (string.charCodeAt(0) === 0xfeff) {
return string.slice(1);
}
return string;
}
}
function JsonToCsv(_input, _config)
{
// Default configuration
/** whether to surround every datum with quotes */
var _quotes = false;
/** whether to write headers */
var _writeHeader = true;
/** delimiting character(s) */
var _delimiter = ',';
/** newline character(s) */
var _newline = '\r\n';
/** quote character */
var _quoteChar = '"';
/** escaped quote character, either "" or <config.escapeChar>" */
var _escapedQuote = _quoteChar + _quoteChar;
/** whether to skip empty lines */
var _skipEmptyLines = false;
/** the columns (keys) we expect when we unparse objects */
var _columns = null;
/** whether to prevent outputting cells that can be parsed as formulae by spreadsheet software (Excel and LibreOffice) */
var _escapeFormulae = false;
unpackConfig();
var quoteCharRegex = new RegExp(escapeRegExp(_quoteChar), 'g');
if (typeof _input === 'string')
_input = JSON.parse(_input);
if (Array.isArray(_input))
{
if (!_input.length || Array.isArray(_input[0]))
return serialize(null, _input, _skipEmptyLines);
else if (typeof _input[0] === 'object')
return serialize(_columns || Object.keys(_input[0]), _input, _skipEmptyLines);
}
else if (typeof _input === 'object')
{
if (typeof _input.data === 'string')
_input.data = JSON.parse(_input.data);
if (Array.isArray(_input.data))
{
if (!_input.fields)
_input.fields = _input.meta && _input.meta.fields || _columns;
if (!_input.fields)
_input.fields = Array.isArray(_input.data[0])
? _input.fields
: typeof _input.data[0] === 'object'
? Object.keys(_input.data[0])
: [];
if (!(Array.isArray(_input.data[0])) && typeof _input.data[0] !== 'object')
_input.data = [_input.data]; // handles input like [1,2,3] or ['asdf']
}
return serialize(_input.fields || [], _input.data || [], _skipEmptyLines);
}
// Default (any valid paths should return before this)
throw new Error('Unable to serialize unrecognized input');
function unpackConfig()
{
if (typeof _config !== 'object')
return;
if (typeof _config.delimiter === 'string'
&& !Papa.BAD_DELIMITERS.filter(function(value) { return _config.delimiter.indexOf(value) !== -1; }).length)
{
_delimiter = _config.delimiter;
}
if (typeof _config.quotes === 'boolean'
|| typeof _config.quotes === 'function'
|| Array.isArray(_config.quotes))
_quotes = _config.quotes;
if (typeof _config.skipEmptyLines === 'boolean'
|| typeof _config.skipEmptyLines === 'string')
_skipEmptyLines = _config.skipEmptyLines;
if (typeof _config.newline === 'string')
_newline = _config.newline;
if (typeof _config.quoteChar === 'string')
_quoteChar = _config.quoteChar;
if (typeof _config.header === 'boolean')
_writeHeader = _config.header;
if (Array.isArray(_config.columns)) {
if (_config.columns.length === 0) throw new Error('Option columns is empty');
_columns = _config.columns;
}
if (_config.escapeChar !== undefined) {
_escapedQuote = _config.escapeChar + _quoteChar;
}
if (typeof _config.escapeFormulae === 'boolean' || _config.escapeFormulae instanceof RegExp) {
_escapeFormulae = _config.escapeFormulae instanceof RegExp ? _config.escapeFormulae : /^[=+\-@\t\r].*$/;
}
}
/** The double for loop that iterates the data and writes out a CSV string including header row */
function serialize(fields, data, skipEmptyLines)
{
var csv = '';
if (typeof fields === 'string')
fields = JSON.parse(fields);
if (typeof data === 'string')
data = JSON.parse(data);
var hasHeader = Array.isArray(fields) && fields.length > 0;
var dataKeyedByField = !(Array.isArray(data[0]));
// If there a header row, write it first
if (hasHeader && _writeHeader)
{
for (var i = 0; i < fields.length; i++)
{
if (i > 0)
csv += _delimiter;
csv += safe(fields[i], i);
}
if (data.length > 0)
csv += _newline;
}
// Then write out the data
for (var row = 0; row < data.length; row++)
{
var maxCol = hasHeader ? fields.length : data[row].length;
var emptyLine = false;
var nullLine = hasHeader ? Object.keys(data[row]).length === 0 : data[row].length === 0;
if (skipEmptyLines && !hasHeader)
{
emptyLine = skipEmptyLines === 'greedy' ? data[row].join('').trim() === '' : data[row].length === 1 && data[row][0].length === 0;
}
if (skipEmptyLines === 'greedy' && hasHeader) {
var line = [];
for (var c = 0; c < maxCol; c++) {
var cx = dataKeyedByField ? fields[c] : c;
line.push(data[row][cx]);
}
emptyLine = line.join('').trim() === '';
}
if (!emptyLine)
{
for (var col = 0; col < maxCol; col++)
{
if (col > 0 && !nullLine)
csv += _delimiter;
var colIdx = hasHeader && dataKeyedByField ? fields[col] : col;
csv += safe(data[row][colIdx], col);
}
if (row < data.length - 1 && (!skipEmptyLines || (maxCol > 0 && !nullLine)))
{
csv += _newline;
}
}
}
return csv;
}
/** Encloses a value around quotes if needed (makes a value safe for CSV insertion) */
function safe(str, col)
{
if (typeof str === 'undefined' || str === null)
return '';
if (str.constructor === Date)
return JSON.stringify(str).slice(1, 25);
var needsQuotes = false;
if (_escapeFormulae && typeof str === "string" && _escapeFormulae.test(str)) {
str = "'" + str;
needsQuotes = true;
}
var escapedQuoteStr = str.toString().replace(quoteCharRegex, _escapedQuote);
needsQuotes = needsQuotes
|| _quotes === true
|| (typeof _quotes === 'function' && _quotes(str, col))
|| (Array.isArray(_quotes) && _quotes[col])
|| hasAny(escapedQuoteStr, Papa.BAD_DELIMITERS)
|| escapedQuoteStr.indexOf(_delimiter) > -1
|| escapedQuoteStr.charAt(0) === ' '
|| escapedQuoteStr.charAt(escapedQuoteStr.length - 1) === ' ';
return needsQuotes ? _quoteChar + escapedQuoteStr + _quoteChar : escapedQuoteStr;
}
function hasAny(str, substrings)
{
for (var i = 0; i < substrings.length; i++)
if (str.indexOf(substrings[i]) > -1)
return true;
return false;
}
}
/** ChunkStreamer is the base prototype for various streamer implementations. */
function ChunkStreamer(config)
{
this._handle = null;
this._finished = false;
this._completed = false;
this._halted = false;
this._input = null;
this._baseIndex = 0;
this._partialLine = '';
this._rowCount = 0;
this._start = 0;
this._nextChunk = null;
this.isFirstChunk = true;
this._completeResults = {
data: [],
errors: [],
meta: {}
};
replaceConfig.call(this, config);
this.parseChunk = function(chunk, isFakeChunk)
{
// First chunk pre-processing
if (this.isFirstChunk && isFunction(this._config.beforeFirstChunk))
{
var modifiedChunk = this._config.beforeFirstChunk(chunk);
if (modifiedChunk !== undefined)
chunk = modifiedChunk;
}
this.isFirstChunk = false;
this._halted = false;
// Rejoin the line we likely just split in two by chunking the file
var aggregate = this._partialLine + chunk;
this._partialLine = '';
var results = this._handle.parse(aggregate, this._baseIndex, !this._finished);
if (this._handle.paused() || this._handle.aborted()) {
this._halted = true;
return;
}
var lastIndex = results.meta.cursor;
if (!this._finished)
{
this._partialLine = aggregate.substring(lastIndex - this._baseIndex);
this._baseIndex = lastIndex;
}
if (results && results.data)
this._rowCount += results.data.length;
var finishedIncludingPreview = this._finished || (this._config.preview && this._rowCount >= this._config.preview);
if (IS_PAPA_WORKER)
{
global.postMessage({
results: results,
workerId: Papa.WORKER_ID,
finished: finishedIncludingPreview
});
}
else if (isFunction(this._config.chunk) && !isFakeChunk)
{
this._config.chunk(results, this._handle);
if (this._handle.paused() || this._handle.aborted()) {
this._halted = true;
return;
}
results = undefined;
this._completeResults = undefined;
}
if (!this._config.step && !this._config.chunk) {
this._completeResults.data = this._completeResults.data.concat(results.data);
this._completeResults.errors = this._completeResults.errors.concat(results.errors);
this._completeResults.meta = results.meta;
}
if (!this._completed && finishedIncludingPreview && isFunction(this._config.complete) && (!results || !results.meta.aborted)) {
this._config.complete(this._completeResults, this._input);
this._completed = true;
}
if (!finishedIncludingPreview && (!results || !results.meta.paused))
this._nextChunk();
return results;
};
this._sendError = function(error)
{
if (isFunction(this._config.error))
this._config.error(error);
else if (IS_PAPA_WORKER && this._config.error)
{
global.postMessage({
workerId: Papa.WORKER_ID,
error: error,
finished: false
});
}
};
function replaceConfig(config)
{
// Deep-copy the config so we can edit it
var configCopy = copy(config);
configCopy.chunkSize = parseInt(configCopy.chunkSize); // parseInt VERY important so we don't concatenate strings!
if (!config.step && !config.chunk)
configCopy.chunkSize = null; // disable Range header if not streaming; bad values break IIS - see issue #196
this._handle = new ParserHandle(configCopy);
this._handle.streamer = this;
this._config = configCopy; // persist the copy to the caller
}
}
function NetworkStreamer(config)
{
config = config || {};
if (!config.chunkSize)
config.chunkSize = Papa.RemoteChunkSize;
ChunkStreamer.call(this, config);
var xhr;
if (IS_WORKER)
{
this._nextChunk = function()
{
this._readChunk();
this._chunkLoaded();
};
}
else
{
this._nextChunk = function()
{
this._readChunk();
};
}
this.stream = function(url)
{
this._input = url;
this._nextChunk(); // Starts streaming
};
this._readChunk = function()
{
if (this._finished)
{
this._chunkLoaded();
return;
}
xhr = new XMLHttpRequest();
if (this._config.withCredentials)
{
xhr.withCredentials = this._config.withCredentials;
}
if (!IS_WORKER)
{
xhr.onload = bindFunction(this._chunkLoaded, this);
xhr.onerror = bindFunction(this._chunkError, this);
}
xhr.open(this._config.downloadRequestBody ? 'POST' : 'GET', this._input, !IS_WORKER);
// Headers can only be set when once the request state is OPENED
if (this._config.downloadRequestHeaders)
{
var headers = this._config.downloadRequestHeaders;
for (var headerName in headers)
{
xhr.setRequestHeader(headerName, headers[headerName]);
}
}
if (this._config.chunkSize)
{
var end = this._start + this._config.chunkSize - 1; // minus one because byte range is inclusive
xhr.setRequestHeader('Range', 'bytes=' + this._start + '-' + end);
}
try {
xhr.send(this._config.downloadRequestBody);
}
catch (err) {
this._chunkError(err.message);
}
if (IS_WORKER && xhr.status === 0)
this._chunkError();
};
this._chunkLoaded = function()
{
if (xhr.readyState !== 4)
return;
if (xhr.status < 200 || xhr.status >= 400)
{
this._chunkError();
return;
}
// Use chunckSize as it may be a diference on reponse lentgh due to characters with more than 1 byte
this._start += this._config.chunkSize ? this._config.chunkSize : xhr.responseText.length;
this._finished = !this._config.chunkSize || this._start >= getFileSize(xhr);
this.parseChunk(xhr.responseText);
};
this._chunkError = function(errorMessage)
{
var errorText = xhr.statusText || errorMessage;
this._sendError(new Error(errorText));
};
function getFileSize(xhr)
{
var contentRange = xhr.getResponseHeader('Content-Range');
if (contentRange === null) { // no content range, then finish!
return -1;
}
return parseInt(contentRange.substring(contentRange.lastIndexOf('/') + 1));
}
}
NetworkStreamer.prototype = Object.create(ChunkStreamer.prototype);
NetworkStreamer.prototype.constructor = NetworkStreamer;
function FileStreamer(config)
{
config = config || {};
if (!config.chunkSize)
config.chunkSize = Papa.LocalChunkSize;
ChunkStreamer.call(this, config);
var reader, slice;
// FileReader is better than FileReaderSync (even in worker) - see http://stackoverflow.com/q/24708649/1048862
// But Firefox is a pill, too - see issue #76: https://github.com/mholt/PapaParse/issues/76
var usingAsyncReader = typeof FileReader !== 'undefined'; // Safari doesn't consider it a function - see issue #105
this.stream = function(file)
{
this._input = file;
slice = file.slice || file.webkitSlice || file.mozSlice;
if (usingAsyncReader)
{
reader = new FileReader(); // Preferred method of reading files, even in workers
reader.onload = bindFunction(this._chunkLoaded, this);
reader.onerror = bindFunction(this._chunkError, this);
}
else
reader = new FileReaderSync(); // Hack for running in a web worker in Firefox
this._nextChunk(); // Starts streaming
};
this._nextChunk = function()
{
if (!this._finished && (!this._config.preview || this._rowCount < this._config.preview))
this._readChunk();
};
this._readChunk = function()
{
var input = this._input;
if (this._config.chunkSize)
{
var end = Math.min(this._start + this._config.chunkSize, this._input.size);
input = slice.call(input, this._start, end);
}
var txt = reader.readAsText(input, this._config.encoding);
if (!usingAsyncReader)
this._chunkLoaded({ target: { result: txt } }); // mimic the async signature
};
this._chunkLoaded = function(event)
{
// Very important to increment start each time before handling results
this._start += this._config.chunkSize;
this._finished = !this._config.chunkSize || this._start >= this._input.size;
this.parseChunk(event.target.result);
};
this._chunkError = function()
{
this._sendError(reader.error);
};
}
FileStreamer.prototype = Object.create(ChunkStreamer.prototype);
FileStreamer.prototype.constructor = FileStreamer;
function StringStreamer(config)
{
config = config || {};
ChunkStreamer.call(this, config);
var remaining;
this.stream = function(s)
{
remaining = s;
return this._nextChunk();
};
this._nextChunk = function()
{
if (this._finished) return;
var size = this._config.chunkSize;
var chunk;
if(size) {
chunk = remaining.substring(0, size);
remaining = remaining.substring(size);
} else {
chunk = remaining;
remaining = '';
}
this._finished = !remaining;
return this.parseChunk(chunk);
};
}
StringStreamer.prototype = Object.create(StringStreamer.prototype);
StringStreamer.prototype.constructor = StringStreamer;
function ReadableStreamStreamer(config)
{
config = config || {};
ChunkStreamer.call(this, config);
var queue = [];
var parseOnData = true;
var streamHasEnded = false;
this.pause = function()
{
ChunkStreamer.prototype.pause.apply(this, arguments);
this._input.pause();
};
this.resume = function()
{
ChunkStreamer.prototype.resume.apply(this, arguments);
this._input.resume();
};
this.stream = function(stream)
{
this._input = stream;
this._input.on('data', this._streamData);
this._input.on('end', this._streamEnd);
this._input.on('error', this._streamError);
};
this._checkIsFinished = function()
{
if (streamHasEnded && queue.length === 1) {
this._finished = true;
}
};
this._nextChunk = function()
{
this._checkIsFinished();
if (queue.length)
{
this.parseChunk(queue.shift());
}
else
{
parseOnData = true;
}
};
this._streamData = bindFunction(function(chunk)
{
try
{
queue.push(typeof chunk === 'string' ? chunk : chunk.toString(this._config.encoding));
if (parseOnData)
{
parseOnData = false;
this._checkIsFinished();
this.parseChunk(queue.shift());
}
}
catch (error)
{
this._streamError(error);
}
}, this);
this._streamError = bindFunction(function(error)
{
this._streamCleanUp();
this._sendError(error);
}, this);
this._streamEnd = bindFunction(function()
{
this._streamCleanUp();
streamHasEnded = true;
this._streamData('');
}, this);
this._streamCleanUp = bindFunction(function()
{
this._input.removeListener('data', this._streamData);
this._input.removeListener('end', this._streamEnd);
this._input.removeListener('error', this._streamError);
}, this);
}
ReadableStreamStreamer.prototype = Object.create(ChunkStreamer.prototype);
ReadableStreamStreamer.prototype.constructor = ReadableStreamStreamer;
function DuplexStreamStreamer(_config) {
var Duplex = require('stream').Duplex;
var config = copy(_config);
var parseOnWrite = true;
var writeStreamHasFinished = false;
var parseCallbackQueue = [];
var stream = null;
this._onCsvData = function(results)
{
var data = results.data;
if (!stream.push(data) && !this._handle.paused()) {
// the writeable consumer buffer has filled up
// so we need to pause until more items
// can be processed
this._handle.pause();
}
};
this._onCsvComplete = function()
{
// node will finish the read stream when
// null is pushed
stream.push(null);
};
config.step = bindFunction(this._onCsvData, this);
config.complete = bindFunction(this._onCsvComplete, this);
ChunkStreamer.call(this, config);
this._nextChunk = function()
{
if (writeStreamHasFinished && parseCallbackQueue.length === 1) {
this._finished = true;
}
if (parseCallbackQueue.length) {
parseCallbackQueue.shift()();
} else {
parseOnWrite = true;
}
};
this._addToParseQueue = function(chunk, callback)
{
// add to queue so that we can indicate
// completion via callback
// node will automatically pause the incoming stream
// when too many items have been added without their
// callback being invoked
parseCallbackQueue.push(bindFunction(function() {
this.parseChunk(typeof chunk === 'string' ? chunk : chunk.toString(config.encoding));
if (isFunction(callback)) {
return callback();
}
}, this));
if (parseOnWrite) {
parseOnWrite = false;
this._nextChunk();
}
};
this._onRead = function()
{
if (this._handle.paused()) {
// the writeable consumer can handle more data
// so resume the chunk parsing
this._handle.resume();
}
};
this._onWrite = function(chunk, encoding, callback)
{
this._addToParseQueue(chunk, callback);
};
this._onWriteComplete = function()
{
writeStreamHasFinished = true;
// have to write empty string
// so parser knows its done
this._addToParseQueue('');
};
this.getStream = function()