Elixir web development 101: collaborative todolist with realtime updates
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Re: Elixir web development 101: collaborative todolist with realtime updates
#2OT, but what software did you use to make those gifs on Ubuntu?
Re: Elixir web development 101: collaborative todolist with realtime updates
#3> channel.on('update:todo' ...
> channel.push('delete:todo' ...
> Have a CRUD interface over websocket
REST over websockets. What's the advantage over HTTP? I know websockets allow for pushing data to clients, but this is pull so apparently there should be no advantage, only more code to write.
Edit: maybe you're sharing updates among all the users connected to the server. Still, for sending requests HTTP is enough. Any performance advantage by using websockets?
Re: Elixir web development 101: collaborative todolist with realtime updates
#4I really like absinthe with apollo/subscripions on the frontend for realtime updates.
Re: Elixir web development 101: collaborative todolist with realtime updates
#5OT, but what software did you use to make those gifs on Ubuntu?
Hi, I used gtk-recordmydesktop (beware it will freeze your desktop under Ubuntu 17.10 Gnome but works fine under Unity). It gives you an .ogv file and then there's some editing to get a gif. I described the process at the end of: https://blog.openbloc.fr/javascript-es2015-starter-kit/
Mainly convert the .ogv to .mp4 with ffmpeg (don't have the command here), create a png palette from the video so your gif colors are more accurate and use ffmpeg to create the gif:
ffmpeg -y -i video.mp4 -vf fps=10,scale=800:-1:flags=lanczos,palettegen palette.png
ffmpeg -i video.mp4 -i palette.png -filter_complex 'fps=1,scale=800:-1:flags=lanczos,setpts=0.25*PTS[x];[x][1:v]paletteuse' todoApp.gif
Re: Elixir web development 101: collaborative todolist with realtime updates
#6> channel.on('update:todo' ... > channel.push('delete:todo' ... > Have a CRUD interface over websocket REST over websockets. What's the advantage over HTTP? I know websockets allow for pushing data to clients, but this is pull so apparently there should be no advantage, only more code to write. Edit: maybe you're sharing updates among all the users connected to the server. Still, for sending requests HTTP is enough.…
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Re: Elixir web development 101: collaborative todolist with realtime updates
#7> channel.on('update:todo' ... > channel.push('delete:todo' ... > Have a CRUD interface over websocket REST over websockets. What's the advantage over HTTP? I know websockets allow for pushing data to clients, but this is pull so apparently there should be no advantage, only more code to write. Edit: maybe you're sharing updates among all the users connected to the server. Still, for sending requests HTTP is enough.…
Websockets provide full-duplex communication channels over a single TCP connection without the overhead of a http request/response cycle. For realtime applications such as the one described in this post or for a chat application, there is a significant performance benefit over plain http. Maintaining open websocket connections is also very cheap in terms of memory used as well as cpu resources.
Re: Elixir web development 101: collaborative todolist with realtime updates
#8> channel.on('update:todo' ... > channel.push('delete:todo' ... > Have a CRUD interface over websocket REST over websockets. What's the advantage over HTTP? I know websockets allow for pushing data to clients, but this is pull so apparently there should be no advantage, only more code to write. Edit: maybe you're sharing updates among all the users connected to the server. Still, for sending requests HTTP is enough.…
Apart from the obvious push capabilities, yes, websocket has much less overhead and is faster than HTTPS.
Once the connection is established, you can send requests starting at 1 byte size, whereas HTTP needs the full headers on every request.
HTTPS also has a lot of handshake overhead, where you need 2-3 round trips per request instead of a single one with websocket. This can make a world of difference in a 150+ ping situation, where HTTP feels sluggish and websocket feels instant.
Re: Elixir web development 101: collaborative todolist with realtime updates
#9> channel.on('update:todo' ... > channel.push('delete:todo' ... > Have a CRUD interface over websocket REST over websockets. What's the advantage over HTTP? I know websockets allow for pushing data to clients, but this is pull so apparently there should be no advantage, only more code to write. Edit: maybe you're sharing updates among all the users connected to the server. Still, for sending requests HTTP is enough.…
Apart from the obvious push capabilities, yes, websocket has much less overhead and is faster than HTTPS. Once the connection is established, you can send requests starting at 1 byte size, whereas HTTP needs the full headers on every request. HTTPS also has a lot of handshake overhead, where you need 2-3 round trips per request instead of a single one with websocket. This can make a world of difference in a 150+ ping…
actually, both HTTPS and WebSocket over TLS (wss://) require a TLS handshake, so it's not like you're constantly doing that after you've loaded the page, but HTTP request/response header sizes could def be a concern.
Re: Elixir web development 101: collaborative todolist with realtime updates
#10Non-representative anecdote : i've recently heard of two teams that started using elixir, they both came from a ruby background, and in both case they weren't using OTP.
They both justified using elixir because it was "closer to ruby" (???), and they both seemed to live a pretty difficult time with that language. Which makes me wonder : why would you ever want to use such a special language (purely functional isn't for everyone) if you don't have any scalability issue, and don't even use OTP ?