Server-sent events explicitly requires --stream

If I have a server-sent event source and try to simply do

http get http://localhost:1729/stream/all

I get output that looks something like this:

HTTP/1.1 200 OK
Cache-Control: no-cache
Content-Type: text/event-stream
Date: Sat, 29 Aug 2015 12:18:00 GMT
Server: TornadoServer/4.2.1
Transfer-Encoding: chunked

followed by none of the streamed data. This can be worked around by setting the --stream flag. However, better behavior would be to automatically enable streaming support when Content-Type is text/event-stream.

[rwish]

Hi, I’m a newbie to open source projects. I would like to contribute to make HTTPie to automatically recognize server sent events. Could you please provide me with more info and can I work on this issue?

[sigmavirus24]

Actually, the best behaviour is to auto-enable --stream when you see Transfer-Encoding: chunked because the length is indeterminate. That said, this is going to be near impossible to do for httpie. An example of what httpie is doing under the covers is

import requests
r = requests.get('http://localhost:1729/stream/all')
print_headers(r)
print_body(r)

What it does with --stream is:

import requests
r = requests.get('http://localhost:1729/stream/all', stream=True)
print_headers(r)
print_body(r)

This means that by the time httpie has received the headers it’s too late to begin streaming. httpie would need to perform a HEAD request for every URL to determine whether or not to automatically enable --stream for the user which would be wildly inefficient. While this is certainly a desirable feature, I’m not sure it’s practical.

The one way to acommodate this would be for httpie to always pass stream=True to requests and if --stream isn’t provided and the headers aren’t something that should require streaming, then it reads the whole content into memory (accessing the content attribute will take care of that). Otherwise, it streams appropriately.

I’m not sure if @jkbrzt wants httpie to absorb some logic from it’s dependencies though just to perform some magic.