Ezs NPM | npm.io

Make pipeline of streams easy : Easy Streams

It's just a wrapper to build Stream transformers with functional style. It's like the koa / expressjs middlewares !

Example

const ezs = require('ezs')

ezs.use(require('ezs-basics'));

process.stdin.resume();
process.stdin.setEncoding('utf8');
process.stdin
  .pipe(ezs('split', { delimiter: "\n" }))
  .pipe(ezs('counter'))
  .pipe(ezs((input, output) => output.send(input.toString()));
  .pipe(process.stdout);

Installation

With npm:

$ npm install ezs

Concepts

Scope

Each statement function have its own scope and can access to few methods :

this.isLast()
this.isFirst()
this.getIndex()
this.getParam(name, defaultValue)

Output Object

Output object is an object with few methods :

output.write(something)
output.end()
output.send(something)
output.close()
output.stop(withAnError)

With a sync statement, you can break the pipe with throw but with an async statement, you should use stop(with An Error) instead of throw.

CLI

The command line interface is used to create run pipelines described in .ini files.

It is also possible to launch a web server allowing remote execution of .ini files

$ ezs -h                                                                                                                                                                   ven. 15 mars 2019 16:15:20 CET
Usage: ezs [options] [<file>|<directory>] [<file2> <file3> ...]

Options:
  --help         Affiche de l'aide                                     [booléen]
  --version      Affiche le numéro de version                          [booléen]
  --verbose, -v  Enable debug mode with DEBUG=ezs      [booléen] [défaut: false]
  --daemon, -d   Launch daemon on a directory containing commands script
                                                           [chaine de caractère]
  --server, -s   Server to dispach commands                [chaine de caractère]
  --env, -e      Execute commands with environement variables as input
                                                       [booléen] [défaut: false]

for more information, find our manual at https://github.com/touv/node-ezs

API Documentation

ezs(statement : Mixed, params : Object) : Stream

Converts a transform stream with existing function or adhoc function.

	const ezs = require('ezs'),
	let transformer = ezs(function(input, output) {
		output.send(input.toString())
	})

ezs.use(module: Function) : None

Adding bundle of statements. see the avaible modules here : https://www.npmjs.com/browse/keyword/ezs

	import ezs from 'ezs';
	import basics from 'ezs-basics';
	import files from 'ezs-files';

	ezs.use(basics);
	ezs.use(files);

ezs.catch(func : Function)

catch Error in NodeJS pipeline

    // Example #1
    process.stdin
        .pipe(ezs('truncate', { length: 100 }))
        .pipe(ezs((d, f) => f.send(new Error('Badaboum')))))
        .pipe(ezs.catch(e => e)) // catch errors in chunks and throw a error, which breaking the pipeline
        .on('error', console.error)

    // Example #2
    process.stdin
        .pipe(ezs('truncate', { length: 100 }))
        .pipe(ezs((d, f) => f.send(new Error('Badaboum')))))
        .pipe(ezs.catch(e => console.error('Warning:', e))) // catch errors in chunks to display them without breaking the pipeline

ezs.toBuffer(options : Object)

get chunk of in NodeJS pipeline and send Buffer of the chunk

    process.stdin
        .pipe(ezs('replace', { path: 'id', value: 'xxxxx' }))
        .pipe(ezs('dump'))
        .pipe(ezs.toBuffer())
        .pipe(process.stdout);

Statements

assign

Take Object and add new field

Parameters

data
feed
path String? path of the new field
value String? value of the new field

Returns Object

concat

Take all String, concat them and thow just one

Parameters

data
feed
beginWith String? Add value at the begin
joinWith String? use value to join 2 chunk
endWith String? Add value at the end

Returns String

debug

Take Object , print it and throw the same object

Parameters

data
feed
level String console level : log or error (optional, default log)
text String text before the dump (optional, default valueOf)
path String? path of field to print

Returns Object

delegate

Takes an Object delegate processing to an external pipeline

Parameters

data
feed
file String? the external pipeline is descrbied in a file
script String? the external pipeline is descrbied in a sting of characters
commands String? the external pipeline is descrbied in object

Returns Object

dispatch

Takes an Object dispatch processing to an external pipeline in one or more servers

Parameters

data
feed
server String? servers to dispatch data
file String? the external pipeline is descrbied in a file
script String? the external pipeline is descrbied in a sting of characters
commands String? the external pipeline is descrbied in object