Does node.js not include packages in opkg yet?

Boken Lin

@Fred-Blais Not yet, unfortunately... But we won't stop until it's done! Getting Javascript support is something we've promised, and we'll deliver it in both Node.js and IoT.js

@Christopher-Hiller Yes, npm is very doable. The only hard part is the node-gyp stuff which compiles non-Javascript source to binary (because Omega doesn't have a huge amount of computing power), but our solution to that is to build a npm repo with pre-compiled modules that can be just installed with npm.

Philipp Czarnetzki

Is there any way to cross compile node addons for MIPS because if i compile it with Ubuntu 15.10 it says that my addon dont has a correct ELF Header.
Im pretty much done porting the fast-gpio lib to node.js but i have this error weile requiring it.

Boken Lin

@Philipp-Czarnetzki Can you walk us through how you are compiling the module?

Philipp Czarnetzki

@Boken-Lin: Sure, i'd love to!
First my Specs:

Asus Zenbook (ux32a)
Ubuntu 15.10 64bit (just a fresh install for the cross compiling, build-essential, gcc & etc preinstalled)

Well i thought i can make a wrapper for "fast-gpio" using Windows 7 64bit but then i saw that it requires unix only headers.
Hmmm, ok, just for this i have made a clean install of ubuntu 15.10 on my laptop, installed node and npm and installed node-gyp.
I ported most of the code on my Windows PC and copied all to my laptop and compiled it with node-gyp.
Here my gyp file:

{
    'targets': [
        {
        'target_name': 'gpio',
        'sources': [ 'src/gpio.cpp' ],
        'include_dirs': [ 'inc' ]
        }
}

And a screen of the error:
Error

Here is also the readelf log:

> readelf -h gpio.node
ELF-Header:
  Magic:   7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 
  Class:                            ELF64
  Data:                             2er-Komplement, Little-Endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI-Version:                       0
  Type:                               DYN (splitted Objektafile)
  Maschine:                          Advanced Micro Devices X86-64
  Version:                           0x1
  Entry point address:               0xc30
  Begin of Program-Header:          64 (Bytes in File)
  Begin of Sektions-header:          11376 (Bytes in File)
  Flags:                             0x0
  Size of Headers:              64 (Byte)
  Size of the Program-Header:         56 (Byte)
  Number of program headers:         7
  Size of Sektions-Header:         64 (bytes)
  Count of Sektions-Header:        27
  Sektions-Header Stringtabellen-Index: 24

Thats pretty much it.
Greetings from Germany!

Fred Blais

@Boken-Lin said:

@Fred-Blais Not yet, unfortunately... But we won't stop until it's done! Getting Javascript support is something we've promised, and we'll deliver it in both Node.js and IoT.js

Have a look at this document : http://www.soscon.net/download/day28/GB2/S_28_1050_이춘석.pdf

It looks to me that IoT.js is a much more logical choice than Node.js on the Omega
JerryScript takes anywhere from 100-300kb depending on the install, the V8 javascript engine takes about 10MB.
10MB is a lot on a 16MB device... IoT.js is also Node compatible.

Boken Lin

@Philipp-Czarnetzki Seems like you are trying to compile the module for x86-64? Did you set up the cross-compile environment for Omega? node-gyp by default compiles the module for the machine you are running it on. In order to use it to compile for the Omega, you will need to tell node-gyp to compile using the Omega toolchain. You can download the Omega toolchain from here: https://s3-us-west-2.amazonaws.com/onion-cdn/community/openwrt/OpenWrt-Toolchain-ar71xx-generic_gcc-4.8-linaro_uClibc-0.9.33.2.Linux-x86_64.tar.bz2.

Boken Lin

@Fred-Blais Yes, I totally agree that IoT.js is a much better choice for embedded platforms like the Omega. I wish we had heard about it earlier Also, thanks for the link to the document. It provides quite a bit of useful information.

Philipp Czarnetzki

@Boken-Lin How Do I do this?

Boken Lin

@Philipp-Czarnetzki Have you looked at our wiki article on setting up the cross-compile environment for the Omega? If not, it's here: https://wiki.onion.io/Tutorials/Cross-Compile. Once you have that setup, you need to setup the environment variables like CC and CXX to point node-gyp to the compiler for cross compilation. To compile you will need to use node-gyp --arch mips configure build, however, bear in mind that most modules out there probably don't have MIPS architecture support designed, you might need to manually port over some stuff if you see some error during your compilation.

Philipp Czarnetzki

@Boken-Lin I have compiled my module for MIPS Arch but now i get a "File not found" Error from node if i want to require it.

root@Omega-XXXX:/mnt/sda1/test/build/Release# node`
> var hello = require('./hello')
Error: File not found                                                                                                                                                                         
    at Module.load (module.js:356:32)                                                                                                                                                         
    at Function.Module._load (module.js:312:12)                                                                                                                                               
    at Module.require (module.js:364:17)                                                                                                                                                      
    at require (module.js:380:17)                                                                                                                                                             
    at repl:1:13                                                                                                                                                                              
    at REPLServer.self.eval (repl.js:110:21)                                                                                                                                                  
    at repl.js:249:20                                                                                                                                                                         
    at REPLServer.self.eval (repl.js:122:7)                                                                                                                                                   
    at Interface.<anonymous> (repl.js:239:12)                                                                                                                                                 
    at Interface.EventEmitter.emit (events.js:95:17)

Chris Ward

@Philipp-Czarnetzki where did you put the hello file? Accessing it with ./hello would mean that a file called 'hello' without a .js is being looked for in the same folder you executed the command in.

Boken Lin

@Philipp-Czarnetzki Did you place the module inside a folder called node_modules?

Chris Ward

Node file/directory/module loading
https://nodejs.org/api/modules.html

Philipp Czarnetzki

@Boken-Lin Nope i copied the entire folder containing the compiled hello world example and launched a repl in the folder that i posted above.

Boken Lin

@Philipp-Czarnetzki I think in order to require a module, you will need to put it in node_modules directory. If you just have the hello directory, you should try require('./hello/hello');.

Philipp Czarnetzki

@Boken-Lin I've placed it in a hello folder within node_modules but if i require it like you said i get a Module/File not found, i also placed a package.json in there but it wont work

Boken Lin

@Philipp-Czarnetzki Did you change the name of your JS file in the hello folder to index.js? I believe that's the default file name for the require system to start looking.

Steve Fister

@Boken-Lin Ok, so I'm having an issue running a node package on the Omega. Node works fine for simple things, but with the node-tweet-stream NPM package (installed on my Mac first, then copied over to the Omega), I continue to receive an error (see below). I backed my Mac node version down to v0.10.5 and ran the script without error. However, when the same exact script is run on the Omega, I get the following error. Note that node-tweet-stream is an uncompiled module....any ideas??

/mnt/sda1/node-tweet-stream/node_modules/node-tweet-stream/lib/twitter.js:270
  this.stream.abort()
              ^
TypeError: Cannot call method 'abort' of null
    at Twitter.abort (/mnt/sda1/node-tweet-stream/node_modules/node-tweet-stream/lib/twitter.js:270:15)
    at null.<anonymous> (/mnt/sda1/node-tweet-stream/node_modules/node-tweet-stream/lib/twitter.js:257:10)
    at Request.EventEmitter.emit (events.js:95:17)
    at IncomingMessage.<anonymous> (/mnt/sda1/node-tweet-stream/node_modules/node-tweet-stream/node_modules/request/request.js:965:12)
    at IncomingMessage.EventEmitter.emit (events.js:95:17)
    at readableAddChunk (_stream_readable.js:132:14)
    at IncomingMessage.Readable.push (_stream_readable.js:113:10)
    at HTTPParser.parserOnBody [as onBody] (http.js:140:22)
    at CleartextStream.socketOnData [as ondata] (http.js:1535:20)
    at CleartextStream.read [as _read] (tls.js:470:10)

Boken Lin

@Steve-Fister Hmmm, that's very strange. From the error message it seems that this wasn't correctly referenced, so it's an empty object. What was the line in your code that triggered this error?

Steve Fister

@Boken-Lin Well, it appears that something is missing from either the node.js package or from the OS. I've tried several twitter node modules, all with varying degrees of failure (yet work on my Mac perfectly fine). In particular, the errors seem to indicate the problem is with authenticating to Twitter apis (I have verified the credentials do work as this EXACT same script runs on the Mac).

My code running in index.js is very simple:

var Twit = require('twit')

var T = new Twit({
    consumer_key:         'XXX'
  , consumer_secret:      'XXX'
  , access_token:         'XXX'
  , access_token_secret:  'XXX'
})

//
//  filter the twitter public stream by the word 'mango'.
//
var stream = T.stream('statuses/filter', { track: 'mango' })

stream.on('tweet', function (tweet) {
  console.log(tweet)
})