csv

fs = require 'fs' Stream = require 'stream' utils = require './utils' ### Writing data to a destination ============================= The `csv().to` property provides functions to read from a CSV instance and to write to an external destination. The destination may be a stream, a file or a callback. You may call the `to` function or one of its sub function. For example, here are two identical ways to write to a file: csv.from(data).to('/tmp/data.csv'); csv.from(data).to.path('/tmp/data.csv'); ### module.exports = (csv) -> ### `to(mixed)` ----------- Write from any sort of destination. It should be considered as a convenient function which will discover the nature of the destination where to write the CSV data. If is an function, then the csv will be provided as the first argument of the callback. If it is a string, then it is expected to be a file path. If it is an instance of stream, it consider the object to be an output stream. Here's some examples on how to use this function: csv() .from('"1","2","3","4","5"') .to(function(data){ console.log(data) }) csv() .from('"1","2","3","4","5"') .to('./path/to/file.csv') csv() .from('"1","2","3","4","5"') .to(fs.createWriteStream('./path/to/file.csv')) ### to = (mixed, options) -> error = false switch typeof mixed when 'string' to.path mixed, options when 'object' if mixed instanceof Stream then to.stream mixed, options else error = true when 'function' to.string mixed, options else error = true csv.error new Error "Invalid mixed argument in from" if error csv ### `to.options([options])` ----------------------- Update and retrieve options relative to the output. Return the options as an object if no argument is provided. * `delimiter` Set the field delimiter, one character only, defaults to `options.from.delimiter` which is a comma. * `quote` Defaults to the quote read option. * `quoted` Boolean, default to false, quote all the fields even if not required. * `escape` Defaults to the escape read option. * `columns` List of fields, applied when `transform` returns an object, order matters, see the transform and the columns sections below. * `header` Display the column names on the first line if the columns option is provided. * `lineBreaks` String used to delimit record rows or a special value; special values are 'auto', 'unix', 'mac', 'windows', 'unicode'; defaults to 'auto' (discovered in source or 'unix' if no source is specified). * `flags` Defaults to 'w', 'w' to create or overwrite an file, 'a' to append to a file. Applied when using the `toPath` method. * `newColumns` If the `columns` option is not specified (which means columns will be taken from the reader options, will automatically append new columns if they are added during `transform()`. * `end` Prevent calling `end` on the destination, so that destination is no longer writable. * `eof` Add a linebreak on the last line, default to false, expect a charactere or use '\n' if value is set to "true" The end options is similar to passing `{end: false}` option in `stream.pipe()`. According to the Node.js documentation: > By default end() is called on the destination when the source stream emits end, so that destination is no longer writable. Pass { end: false } as options to keep the destination stream open. ### to.options = (options) -> if options? utils.merge csv.options.to, options if csv.options.to.lineBreaks console.log 'To options linebreaks is replaced by rowDelimiter' unless csv.options.to.rowDelimiter csv.options.to.rowDelimiter = csv.options.to.lineBreaks switch csv.options.to.rowDelimiter when 'auto' csv.options.to.rowDelimiter = null when 'unix' csv.options.to.rowDelimiter = "\n" when 'mac' csv.options.to.rowDelimiter = "\r" when 'windows' csv.options.to.rowDelimiter = "\r\n" when 'unicode' csv.options.to.rowDelimiter = "\u2028" csv else csv.options.to ### `to.string(callback, [options])` ------------------------------ Provide the output string to a callback. csv() .from( '"1","2","3"\n"a","b","c"' ) .to.string( function(data, count){} ) Callback is called with 2 arguments: * data Entire CSV as a string * count Number of stringified records ### to.string = (callback, options) -> @options options data = '' stream = new Stream stream.writable = true stream.write = (d) -> data += d true stream.end = -> callback data, csv.state.countWriten csv.pipe stream csv ### `to.stream(stream, [options])` ------------------------------ Write to a stream. Take a writable stream as first argument and optionally an object of options as a second argument. ### to.stream = (stream, options) -> @options options csv.pipe stream, csv.options.to stream.on 'error', (e) -> csv.error e stream.on 'close', -> csv.emit 'close', csv.state.count csv ### `to.path(path, [options])` -------------------------- Write to a path. Take a file path as first argument and optionally an object of options as a second argument. The `close` event is sent after the file is written. Relying on the `end` event is incorrect because it is sent when parsing is done but before the file is written. ### to.path = (path, options) -> # Merge user provided options @options options # Clone options options = utils.merge {}, csv.options.to # Delete end property which otherwise overwrite `stream.end()` delete options.end # Create the write stream stream = fs.createWriteStream path, options csv.to.stream stream, null csv ### `to.array(path, [options])` -------------------------- Provide the output string to a callback. csv() .from( '"1","2","3"\n"a","b","c"' ) .to.array( function(data, count){} ) Callback is called with 2 arguments: * data Entire CSV as an array of records * count Number of stringified records ### to.array = (callback, options) -> @options options records = [] csv.on 'record', (record) -> records.push record csv.on 'end', -> callback records, csv.state.countWriten csv to