argot

A language for the Internet of Things.

A JavaScript port of Argot SDK.

Documentation

• Dictionary Format
• Argot Message Format

Getting Started

Like all good node packages, you can find Argot in NPM.

Add Argot to your project with

npm install argot --save

Usage

Argot has a single entry point exported as a module, containing three functions that should fulfil all needs.

Pull it into your project with var argot = require('argot');

Of the available functions, one is to read dictionary files and the other two are for reading messages.

Argot.loadDictionary

Load dictionary takes an Argot Dictionary file, reads it and processes the contents into a Library containing data definitions.

• Params: fileName - A file on disk
• Returns: A Q promise containing a library

Example:

var argot = require('argot');
 
argot.loadDictionary('~/a/file/on/disk.dictionary')
  .then(function(lib) {
    // do something with the library here
  })
  .fail(function(err) {
    // uh-oh,
  });

Argot.readMessage

Read an Argot Message, a data type that includes dictionary defintions along with the message content.

• Params: messageStream - A Node readable stream containing the data to be read. The data should conform to the Argot Message format.
• Returns: A Q promise containing the read data and the library that has been built as part of the process

Example:

var argot = require('argot');
 
var stream = aStreamAppears();
 
argot.readMessage(stream)
  .then(function(libAndData) {
    var lib = libAndData[0];
    var data = libAndData[1];
    // do something with the data here
  })
  .fail(function(err) {
    // uh-oh,
  });

Read more about for format at Argot Message Format

Argot.read

Read some data from a stream.

• Params:
  • library - A library containing data definitions
  • data - A Node readable stream of data to be read
  • type - Optional. The type of data being read, this should correspond to a type that the library knows about.
• Returns: The read data. (This function performs no IO so we can run synchronously)

About Argot Definition identifiers, there are two identifiers, a Stream Id and a human readable name ('light.colour', 'person.name', etc). With Argot.js you only need to know about the name identifier. When you call read and supply a type name then Argot knows exactly how to build your data. But without the type, the stream Id needs to be the first thing in the data stream, as a prompt to direct Argot to the type that should be built.

For example, if you have a data type that has a Stream Id of 10 and a name of 'person', you can read an instance of that data with: argot.read(lib,data,'person')

For the same instance data, if you don't know that it's a 'person' type, but you do know that the stream begins with the Stream Id then the type name can be omitted. argot.read(lib,data)

Example, with known type:

var argot = require('argot');
 
argot.loadDictionary('~/a/file/on/disk.dictionary')
  .then(function(lib) {
    var stream = aStreamAppears();
    var data = argot.read(lib,stream,'yourtype');
    // do something with data
  })
  .fail(function(err) {
    // uh-oh,
  });

Example, with unknown type:

var argot = require('argot');
 
argot.loadDictionary('~/a/file/on/disk.dictionary')
  .then(function(lib) {
    var stream = aStreamAppears();
    var data = argot.read(lib,stream);
    // do something with data
  })
  .fail(function(err) {
    // uh-oh,
  });

Development

Check it out the project and run grunt to perform a style check (jshint) and run through the tests.

The main points of interest are:

• argot.js is the main file
• dictionary.js deals with loading dictionaries from a file
• library.js is the Argot library data type

There are a few other files, mostly supplementary.

License

Copyright (c) 2014 Dan Midwood