Web servers in D

[Andrew Chapman via Digitalmars-d-learn]

On Friday, 25 August 2017 at 05:25:09 UTC, Hasen Judy wrote:
> What libraries are people using to run webservers other than 
> vibe.d?
>
> Don't get me wrong I like the async-io aspect of vibe.d but I 
> don't like the weird template language and the fact that it 
> caters to mongo crowd.
>
> I think for D to a have good web story it needs to appeal to 
> serious backend developers, not hipsters who go after fads 
> (mongodb is a fad, jade/haml is a fad).
>
> I probably need to combine several libraries, but the features 
> I'm looking for are:
>
> - Spawn an HTTP server listening on a port, and routing 
> requests to functions/delegates, without hiding the details of 
> the http request/response objects (headers, cookies, etc).
>
> - Support for websockets
>
> - Runs delegates in fibers/coroutines
>
> - Basic database connectivity (No "orm" needed; just raw sql).
>
> - When iterating the result set of a sql query, has the ability 
> to automatically map each row against a struct, and throw if 
> the structure does not match.
>
> - More generally, map any arbitrary object (such as json) to a 
> struct. Something like Zewo/Reflection package for swift[0].
>
> [0]: https://github.com/Zewo/Reflection
>
> I feel like Vibe.d satisfies my first 3 requirements, but for 
> the rest I will probably have to look for something else.

> Don't get me wrong I like the async-io aspect of vibe.d but I 
> don't like the weird template language and the fact that it 
> caters to mongo crowd.

Don't use these components :-)

> - Spawn an HTTP server listening on a port, and routing 
> requests to functions/delegates, without hiding the details of 
> the http request/response objects (headers, cookies, etc).

Vibe.d does this - just don't use the automatic API generation 
feature if you don't like it.  Note, you can get access to the 
request/response objects even if you do use the API generation by 
using an @before method.  E.g. in an interface you may have 
something like this:

@method(HTTPMethod.POST)
@before!getRequestInfo("requestInfo")
@property Token login(LoginRequestMeta login, RequestInfo 
requestInfo);

And then define your getRequestInfo method like this:

static RequestInfo getRequestInfo(HTTPServerRequest req, 
HTTPServerResponse res)
{
	RequestInfo requestInfo;
	requestInfo.headers = req.headers;
	requestInfo.ipAddress = req.clientAddress.toAddressString();
	requestInfo.userAgent = requestInfo.headers.get("User-Agent", 
"");
	
	return requestInfo;
}

In this case I've grabbed the ip address and user agent of the 
user, but you could also grab cookies etc.

> - When iterating the result set of a sql query, has the ability 
> to automatically map each row against a struct, and throw if 
> the structure does not match.

You can do this with MySQL Native whilst using vibe.d.  You might 
do something like this:

Prepared prepared = prepare(this.conn, sql);
prepared.setArgs(params);

auto row = prepared.queryRow();

if (row.isNull()) {
     throw new Exception("Query returned an empty row");
}

T item;
try {
     row.toStruct!T(item);
} catch(Exception e) {

}

Where T is your struct type that you're trying to convert the row 
to.

As for the template language, you could try:
http://code.dlang.org/packages/diamond
https://github.com/repeatedly/mustache-d
There are probably others.