[HttpClient] Document pre-conditions for HttpClient asynchronous behavior

[B-Galati]

Following symfony/symfony#35475

[nicolas-grekas]

this is too early and too scary in the page :)
I would try to make the description more... descriptive.
We feel the stress when reading it, but there is nothing special here, this is normal operations. It needs to be better described of course.

[B-Galati]

Agree for the scary thing :D

Where do you think it would fit the best in the doc?
IMHO it should be mentioned ASAP.

[OskarStark]

What about adding a Troubleshooting headline + a subsection and mentioning not just the solution but also the WHY you came to this point?

[B-Galati]

Not really fan of the troubleshooting section as it's not something unexpected / not normal. For the why: that's a very good idea! I see two things to say that I would like to confirm with all of you: first, the asynchronous behavior only works with the CurlHttpClient, right? Second, curl ext allows to do non blocking IO but it requires to keep a reference to the CurlResponse otherwise it will be garbage collected which forces to resolve pending HTTP request. Le mar. 11 févr. 2020 à 19:36, Oskar Stark <notifications@github.com> a écrit :

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***@***.**** commented on this pull request. ------------------------------ In components/http_client.rst <#13078 (comment)> : > @@ -116,6 +116,14 @@ immediately instead of waiting to receive the response:: This component also supports :ref:`streaming responses <http-client-streaming-responses>` for full asynchronous applications. +.. caution:: What about adding a Troubleshooting headline + a subsection and mentioning not just the solution but also the WHY you came to this point? — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#13078?email_source=notifications&email_token=AAG2REYRJJ6MUEH3H2RRNYDRCLV3NA5CNFSM4KR2LJG2YY3PNVWWK3TUL52HS4DFWFIHK3DMKJSXC5LFON2FEZLWNFSXPKTDN5WW2ZLOORPWSZGOCVC47IA#discussion_r377821586>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAG2REZV252CXLFOXKGZ5QLRCLV3NANCNFSM4KR2LJGQ> .

[nicolas-grekas]

Troubleshooting might make sense to me as there are other behaviors that ppl didn't expect until I explained them on issues (e.g. some exceptions thrown when using for each.)

This section could collect those explanations.

(async works also with the native client, and with the amp one soon.)

[B-Galati]

Troubleshooting might make sense to me as there are other behaviors that ppl didn't expect until I explained them on issues (e.g. some exceptions thrown when using for each.)

I would be glad to add them all in this PR. Would you have issue links that I could use?

(async works also with the native client, and with the amp one soon.)

Awesome!

[nicolas-grekas]

See also #12768 for the doc.

Some related issues I found:

• [HttpClient] Asynchronous request processing breaks when some response have 403 code symfony#35144
• [HttpClient] Uncatchable fatal error on class destruction symfony#31187
• [HttpClient] - Cannot catch TransportException error symfony#34281
• [HttpClient] ClientInterface::stream() throws multiple times on same response symfony#34837
• [HttpClient] Stream throws sometimes symfony#32673

[nicolas-grekas]

Thanks, replaced by #13136