4 ms·

N2O: Erlang Web Framework

98 points by andreygrehov 12y ago

rdtsc 12y ago
This framework is really out there. It is well ... different and interesting. Here are some not so conventional things going on: * Write your page in Erlang. * Even translates Erlang to JS as a parse transform. * Websockets (with a fallback mechanism) is the default connection mechanism. * Don't want to use JSON for some crazy reason? That's alright, user Bert (and ship binary encoded Erlang terms to the browser!). * Can render stuff on the server and send the whole thing over the websocket connection. https://github.com/5HT/n2o https://github.com/5HT/n2o
- toast0 12y ago
  JSON doesn't really fit very well into Erlang structures (at least in r16; I haven't played with r17 yet); so I don't think not using it is that crazy.
  - rdtsc 12y ago
    r17 does have maps, here is a jsx version with maps instead of proplists for example. jsx:decode(<<"{\"library\": \"jsxn\", \"awesome?\": true}">>). #{<<"awesome?">> => true,<<"library">> => <<"jsxn">>} https://github.com/talentdeficit/jsxn https://github.com/talentdeficit/jsxn Speaking of json in general, this reminds me of a part of a talk by Joe Armstrong he gave at the React 2014 conf (K things I know about building Resilient Reactive Sytems) https://www.youtube.com/watch?v=rQIE22e0cW8 https://www.youtube.com/watch?v=rQIE22e0cW8 Not related to Erlang necessarily, he talks about how at Ericsson they build these cell phone network-to-internet gateways and now they go to great lengths to pack data as tightly as possible on the communication channel, bit by bit, to conserve shared bandwidth and then "here come the users and shove json across the pipe, what a travesty!" -- it was a funny statement, and I never really thought of it that way. So I guess shoving binary across websockets like N2O is not totally insane.
    - MrBuddyCasino 12y ago
      I never understood that argument. The reason you can have nice text based formats is that it will all be compressed by the server anyway, or am I missing something?
      - felixgallo 12y ago
        Spoiler alert: servers don't do that, and even if they did, the clients would have to do it too to save bandwidth.
        pessimizer 12y ago
        Content-encoding: gzip
        5HT 12y ago
        This is not applicable to WebSockets.
        yetihehe 12y ago
        Yeah, websockets have their own method: http://stackoverflow.com/questions/19298651/how-does-websocket-compress-messages http://stackoverflow.com/questions/19298651/how-does-websock.... Cowboy already supports x-webkit-deflate-frame, will support more soon.
      - alco 12y ago
        No. The reason people use text based formats is so that they could be read by humans without additional tools. Compression reduces the size but it's not reasonable to claim it works better then a binary format designed for light footprint.
        MrBuddyCasino 12y ago
        Thats what I meant, sorry if the wording was poor.
- hackerboos 12y ago
  >Websockets (with a fallback mechanism) Not enough frameworks make this as seamless as it should be. So it's refreshing to see it done here. I've been looking at Phoenix (Elixir not Erlang) but the problem is that I'll have to do logic to detect when WS are available and do the fallback myself which results in more code server side. I think this is something that should be handled by the framework itself.
  - 5HT 12y ago
    It is handled by N2O automatically. See how https://github.com/5HT/n2o/blob/master/priv/bullet.js https://github.com/5HT/n2o/blob/master/priv/bullet.js
  - chrismccord 12y ago
    I'm the author of Phoenix. I'm glad to hear you're giving it a look! I spent a lot of time thinking about the WS layer and fallback support. Ultimately I settled for standard WS with a small multiplexing layer on top. For those that need fallback, they can drop in websocket-js (flash fallback, compatible with native WS api). Have you taken at look at this for your fallback support? https://github.com/gimite/web-socket-js https://github.com/gimite/web-socket-js Phoenix is still far from 1.0, so any and all feedback is welcome.
    - hackerboos 12y ago
      Admittedly no but I'll give it a look now thanks.
    - findjashua 12y ago
      I'm new to Elixir (and FP in general), but I really like the language. I came across a couple of youtube videos on Phoenix , and it looks really nice (reminds me of Rails). I think something like Sinatra would be even nicer, for 2 reasons: 1. the standard these days is to have a rest api serving json to web/mobile clients, so a Rails-like framework seems overkill 2. Pretty much all my friends who are learning web dev on their own, find Sinatra/Flask way easier to get started with than Rails/Django. Regardless, Elixir (and Phoenix) is a great leap forward compared to the other options for building concurrent, reliable servers. I hope more people try it out before falling for hype/marketing (cough node.js cough mongodb cough cough)
- 5HT 12y ago
  Some mentions about the list: * You can use both Erlang DSL and/or DTL templates * You can use JSON, BERT, RAW BINARY messages. see http://synrc.com/apps/n2o/doc/web/protocol.htm http://synrc.com/apps/n2o/doc/web/protocol.htm * You can use N2O both as server-render and in SPA mode
davidw 12y ago
I think there's still room to innovate in the Erlang/Web space. Chicago Boss was a nice improvement because it ties so much different stuff together. It does have a few issues though, like not being very 'Erlangy' in places: it uses lots of parse transform magic. I think it's the right direction though, in that it's fairly general purpose.

98 points by andreygrehov 12y ago

rdtsc 12y ago

This framework is really out there. It is well ... different and interesting. Here are some not so conventional things going on: * Write your page in Erlang. * Even translates Erlang to JS as a parse transform. * Websockets (with a fallback mechanism) is the default connection mechanism. * Don't want to use JSON for some crazy reason? That's alright, user Bert (and ship binary encoded Erlang terms to the browser!). * Can render stuff on the server and send the whole thing over the websocket connection. https://github.com/5HT/n2o https://github.com/5HT/n2o

toast0 12y ago
JSON doesn't really fit very well into Erlang structures (at least in r16; I haven't played with r17 yet); so I don't think not using it is that crazy.
- rdtsc 12y ago
  r17 does have maps, here is a jsx version with maps instead of proplists for example. jsx:decode(<<"{\"library\": \"jsxn\", \"awesome?\": true}">>). #{<<"awesome?">> => true,<<"library">> => <<"jsxn">>} https://github.com/talentdeficit/jsxn https://github.com/talentdeficit/jsxn Speaking of json in general, this reminds me of a part of a talk by Joe Armstrong he gave at the React 2014 conf (K things I know about building Resilient Reactive Sytems) https://www.youtube.com/watch?v=rQIE22e0cW8 https://www.youtube.com/watch?v=rQIE22e0cW8 Not related to Erlang necessarily, he talks about how at Ericsson they build these cell phone network-to-internet gateways and now they go to great lengths to pack data as tightly as possible on the communication channel, bit by bit, to conserve shared bandwidth and then "here come the users and shove json across the pipe, what a travesty!" -- it was a funny statement, and I never really thought of it that way. So I guess shoving binary across websockets like N2O is not totally insane.
  - MrBuddyCasino 12y ago
    I never understood that argument. The reason you can have nice text based formats is that it will all be compressed by the server anyway, or am I missing something?
    - felixgallo 12y ago
      Spoiler alert: servers don't do that, and even if they did, the clients would have to do it too to save bandwidth.
      - pessimizer 12y ago
        Content-encoding: gzip
        5HT 12y ago
        This is not applicable to WebSockets.
        yetihehe 12y ago
        Yeah, websockets have their own method: http://stackoverflow.com/questions/19298651/how-does-websocket-compress-messages http://stackoverflow.com/questions/19298651/how-does-websock.... Cowboy already supports x-webkit-deflate-frame, will support more soon.
    - alco 12y ago
      No. The reason people use text based formats is so that they could be read by humans without additional tools. Compression reduces the size but it's not reasonable to claim it works better then a binary format designed for light footprint.
      - MrBuddyCasino 12y ago
        Thats what I meant, sorry if the wording was poor.
hackerboos 12y ago
>Websockets (with a fallback mechanism) Not enough frameworks make this as seamless as it should be. So it's refreshing to see it done here. I've been looking at Phoenix (Elixir not Erlang) but the problem is that I'll have to do logic to detect when WS are available and do the fallback myself which results in more code server side. I think this is something that should be handled by the framework itself.
- 5HT 12y ago
  It is handled by N2O automatically. See how https://github.com/5HT/n2o/blob/master/priv/bullet.js https://github.com/5HT/n2o/blob/master/priv/bullet.js
- chrismccord 12y ago
  I'm the author of Phoenix. I'm glad to hear you're giving it a look! I spent a lot of time thinking about the WS layer and fallback support. Ultimately I settled for standard WS with a small multiplexing layer on top. For those that need fallback, they can drop in websocket-js (flash fallback, compatible with native WS api). Have you taken at look at this for your fallback support? https://github.com/gimite/web-socket-js https://github.com/gimite/web-socket-js Phoenix is still far from 1.0, so any and all feedback is welcome.
  - hackerboos 12y ago
    Admittedly no but I'll give it a look now thanks.
  - findjashua 12y ago
    I'm new to Elixir (and FP in general), but I really like the language. I came across a couple of youtube videos on Phoenix , and it looks really nice (reminds me of Rails). I think something like Sinatra would be even nicer, for 2 reasons: 1. the standard these days is to have a rest api serving json to web/mobile clients, so a Rails-like framework seems overkill 2. Pretty much all my friends who are learning web dev on their own, find Sinatra/Flask way easier to get started with than Rails/Django. Regardless, Elixir (and Phoenix) is a great leap forward compared to the other options for building concurrent, reliable servers. I hope more people try it out before falling for hype/marketing (cough node.js cough mongodb cough cough)
5HT 12y ago
Some mentions about the list: * You can use both Erlang DSL and/or DTL templates * You can use JSON, BERT, RAW BINARY messages. see http://synrc.com/apps/n2o/doc/web/protocol.htm http://synrc.com/apps/n2o/doc/web/protocol.htm * You can use N2O both as server-render and in SPA mode

davidw 12y ago

I think there's still room to innovate in the Erlang/Web space. Chicago Boss was a nice improvement because it ties so much different stuff together. It does have a few issues though, like not being very 'Erlangy' in places: it uses lots of parse transform magic. I think it's the right direction though, in that it's fairly general purpose.