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diff --git a/archives/extend/2012-October/000006.html b/archives/extend/2012-October/000006.html new file mode 100644 index 00000000..2e8610ec --- /dev/null +++ b/archives/extend/2012-October/000006.html @@ -0,0 +1,93 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<HTML> + <HEAD> + <TITLE> [99s-extend] cowboy_http_handler type spec + </TITLE> + <LINK REL="Index" HREF="index.html" > + <LINK REL="made" HREF="mailto:extend%40lists.ninenines.eu?Subject=Re%3A%20%5B99s-extend%5D%20cowboy_http_handler%20type%20spec&In-Reply-To=%3C5090660A.2000301%40ninenines.eu%3E"> + <META NAME="robots" CONTENT="index,nofollow"> + <style type="text/css"> + pre { + white-space: pre-wrap; /* css-2.1, curent FF, Opera, Safari */ + } + </style> + <META http-equiv="Content-Type" content="text/html; charset=us-ascii"> + <LINK REL="Previous" HREF="000005.html"> + + </HEAD> + <BODY BGCOLOR="#ffffff"> + <H1>[99s-extend] cowboy_http_handler type spec</H1> + <B>Loïc Hoguin</B> + <A HREF="mailto:extend%40lists.ninenines.eu?Subject=Re%3A%20%5B99s-extend%5D%20cowboy_http_handler%20type%20spec&In-Reply-To=%3C5090660A.2000301%40ninenines.eu%3E" + TITLE="[99s-extend] cowboy_http_handler type spec">essen at ninenines.eu + </A><BR> + <I>Wed Oct 31 00:43:06 CET 2012</I> + <P><UL> + <LI>Previous message: <A HREF="000005.html">[99s-extend] cowboy_http_handler type spec +</A></li> + + <LI> <B>Messages sorted by:</B> + <a href="date.html#6">[ date ]</a> + <a href="thread.html#6">[ thread ]</a> + <a href="subject.html#6">[ subject ]</a> + <a href="author.html#6">[ author ]</a> + </LI> + </UL> + <HR> +<!--beginarticle--> +<PRE>On 10/31/2012 12:38 AM, rambocoder wrote: +><i> Hi everyone, newb questions here: +</I>><i> +</I>><i> Is the reason why the type specification for the init callback lists +</I>><i> various "{loop,..." tuples, because a single module can implement +</I>><i> cowboy_loop_handler and cowboy_http_handler? +</I>><i> And this way, a dializier warning will not be triggered? +</I>><i> <A HREF="https://github.com/extend/cowboy/blob/master/src/cowboy_http_handler.erl#L39">https://github.com/extend/cowboy/blob/master/src/cowboy_http_handler.erl#L39</A> +</I> +Yes that's exactly why. Not the best solution but good enough. + +><i> Because looking at the handler code, +</I>><i> <A HREF="https://github.com/extend/cowboy/blob/master/src/cowboy_protocol.erl#L473">https://github.com/extend/cowboy/blob/master/src/cowboy_protocol.erl#L473</A> if +</I>><i> the {loop, * is returned from init, then the handle(Req,State) will not +</I>><i> be processed. +</I> +You have this one if you just want loops: + +<A HREF="https://github.com/extend/cowboy/blob/master/src/cowboy_loop_handler.erl">https://github.com/extend/cowboy/blob/master/src/cowboy_loop_handler.erl</A> + +Having an identical init in both allows us to use the 2 handlers without +Dialyzer complaining. + +><i> Also, is it safe to say that Handler:init is like "before" in lot's of +</I>><i> web frameworks. I can place validation\authentication logic there. +</I> +Definitely, prepare what you need in init, do what you need to do in +handle and clean up in terminate if needed. + +-- +Loïc Hoguin +Erlang Cowboy +Nine Nines +<A HREF="http://ninenines.eu">http://ninenines.eu</A> + +</PRE> + +<!--endarticle--> + <HR> + <P><UL> + <!--threads--> + <LI>Previous message: <A HREF="000005.html">[99s-extend] cowboy_http_handler type spec +</A></li> + + <LI> <B>Messages sorted by:</B> + <a href="date.html#6">[ date ]</a> + <a href="thread.html#6">[ thread ]</a> + <a href="subject.html#6">[ subject ]</a> + <a href="author.html#6">[ author ]</a> + </LI> + </UL> + +<hr> +<a href="https://lists.ninenines.eu/listinfo/extend">More information about the Extend +mailing list</a><br> +</body></html> |