line-readable-stream

node-line-readable-stream

This is a port of bluesmoon's node-line.input-stream. Provides a stream wrapper for a node.js Readable Stream for line-by-line reading.

How to install

Node:

npm install line-readable-stream

Example Usage

Like Readable Stream with a line event.

JavaScript:

var LineReadableStream = require('line-readable-stream');
var fs = require('fs');

var stream = new LineReadableStream(fs.createReadStream("foo.txt", { flags: "r" }));
stream.setEncoding("utf8");
stream.setDelimiter("\n");  // optional string, defaults to "\n"

stream.on("error", function(err) {
		console.log(err);
	});

stream.on("data", function(chunk) {
		// You don't need to use this event
	});

stream.on("line", function(line) {
		// Sends you lines from the stream delimited by delimiter
	});

stream.on("end", function() {
		// No more data, all line events emitted before this event
	});

stream.on("close", function() {
		// Same as ReadableStream's close event
	});

if(stream.readable) {
	console.log("stream is readable");
}

// Also available: resume(), pipe()

TypeScript:

///<require path="typings/node/node.d.ts"/>
///<require path="node_modules/line-readable-stream/LineReadableStream.d.ts"/>

// If you know a better war to include the .ts file that comes with the npm package, let me know.
import LineReadableStream = require('node_modules/line-readable-stream/LineReadableStream');
import fs = require('fs');

var stream = new LineReadableStream(fs.createReadStream("foo.txt", { flags: "r" }));
stream.setEncoding("utf8");
stream.setDelimiter("\n");  // optional string, defaults to "\n"

stream.on("error", err => console.log(err));

stream.on("data", chunk => {
		// You don't need to use this event
	});

stream.on("line", line => {
		// Sends you lines from the stream delimited by delimiter
		console.log("Line: " + line);
	});

stream.on("end", () => {
		// No more data, all line events emitted before this event
	});

stream.on("close", () => {
		// Same as ReadableStream's close event
	});

if(stream.readable)
	console.log("stream is readable");


// Also available: resume(), pipe()

Usage information

You can also attach listeners to any event specific to the underlying stream, ie, you can listen to the open event for streams created by fs.createReadStream() or the connect event for Net streams.

A side effect of this is that you can add a listener for any junk string and LineReadableStream will pretend that it worked. The event listener may never be called though.

• The delimiter is not included in the line passed to the line handler
• Even though this is called line-readable-stream, you can delimit by any string, so for example, setting delimiter to "\n\n" will read by paragraph (sort of).
• You can set the delimiter to a regular expression, which let's you do cool things like drop multiple blank lines: /[\r\n]+/
• All methods return this, so can be chained