Snap Framework Google Group

snaplet-oauth2: Request for feedback

2013-05-07T09:25:54Z

Hello!
For the last few months I've been working on-and-off on an OAuth 2 Snaplet<[link]>.
This Snaplet should enable people to add OAuth authentication to their
application, without having to worry about how it all works. I've got the
bulk of the work done, and I'm looking for some feedback on what I've done

Any good reason for choosing HsOpenSSL over tls?

2013-05-02T07:10:31Z

Hi all,

I saw that openssl-streams is using HsOpenSSL under the hood. I also saw
this on HsOpenSSL hackage page:

Please note that this project has started at the time when there were no
pure-Haskell implementations of TLS. Now there is tls package (
[link]), which looks pretty saner than

Heist 0.11 Questions

2013-05-01T02:50:56Z

Hello,

I've updated to Heist 0.11 and the semantics seemed to have changed a bit
and so I have a couple questions:

1. Are unbound splice contents still removed from the final document? It
seems they are not. I have cases where attributes still have "${tag}" in
the final document.

Nested sub-views in digestive-functors?

2013-04-22T01:23:30Z

Hey guys. This is a bit off topic but I'm wondering if anyone knows if it's
possible to have nested sub-views in digestive-functors. I suspect not
because I can't get it working with the heist backend. If that is the case,
what's the recommended way to build up a single type from a subset of form

new snaplet; snaplet-coffee

2013-04-15T19:55:39Z

Hello,

I created a snaplet for coffeescript based off of snaplet-fay. Here are
the links:

Hackage:[link]
Github:[link]

Also, I've been using your framework for only about a week now, but so
far I'm loving it!

How can I make response chunks send immediately?

2013-04-09T18:02:24Z

Hi Snap devs,
I have some code that returns a response, the first part of which is static
and the second part dynamic, something like:
site :: Snap ()
site = do
writeBS htmlHead
content <- getSlowContent
writeBS content
When I telnet to the server and issue a request, the response shows

[snap-0.11] Segmentation fault

2013-04-02T10:53:42Z

Hi,

I'm trying to deploy a snap-0.11 application under a sub-url and ran into a
segmentation fault. I could reproduce it via:

mkdir testapp
cd testapp
snap-0.11 init default
cabal-dev install-deps
# change src/Site.hs:85 from
# addRoutes routes
# to
# addRoutes [("/foo/bar", route routes)]

Using output from a compiled splice in another compiled splice.

2013-04-01T16:06:10Z

Hello Snap,

I'm new here and I have a question for you.

Suppose I have two *compiled* splices, one bound to `list-names`
that repeatedly runs its children with `name` and `age` bound to
splices that render some text, and a splice named `greet` that
renders some other text based on the value of a given attribute.

first auth handler :)

2013-03-29T19:15:04Z

Relatively new to haskell and snap here, writing my first auth handlers.
First go is below, I'm sure there's a more haskelly-way to write it. Any
initial tips?
[link]

Running Snap app under sub-url behind Apache

2013-03-12T14:47:06Z

Hi,

I want to install a Snap application which should serve under a sub-url,
for example, [link]. While I know how to setup
Apache as a proxy, I do not know how to setup Snap to consider the site
root as /snap-app.

Thanks in advance,
Björn

home page of Snap

2013-03-03T21:13:04Z

Hi all
May I suggest a little refresh to the main page of snapframework.com, in
the news section? There could be something like "Snap 0.11 was released on
Feb 15th 2013."
Another suggestion would be to add a "Community" link between Blog and
Download and corresponding page. Even though there are links into this list

Re: [Yesod] fresh benchmarks

2013-02-28T09:28:29Z

I think everyone who has been working on the web frameworks (including Bryan
of course) has been doing an awesome job. Every time I dig into more
libraries and packages that have been coming out of these efforts I am just
bowled over with the care and attention, and great design.

(Same for GHC of course, and many other packages.)

emitting CDATA in xml?

2013-02-25T16:02:55Z

Hi,

It looks like Text.XmlHtml's renderXmlFragment always encodes all
TextNodes. Is there a preferred way to render TextNodes containing
<![[CDATA[]]>? If not, would a patch to not escape things inside CDATA
be welcome?

Thanks,

Tycho

(P.S. If there's a better list that here, let me know.)

Simple HTTP method overriding. Code included. Advice solicited.

2013-01-29T08:44:19Z

I have written some simple middleware for use with wrapSite, that will set
the request method appropriately if an "_method" value is submitted along
with a form (like Rails and some other frameworks):
modifyRqMethod :: ByteString -> Handler m v ()
modifyRqMethod m = modifyRequest $ \rq -> rq { rqMethod = Method m }

snap doesn't build with either-3.1

2013-01-27T19:29:13Z

Hi,

on Friday, Edward Kmett uploaded either-3.1, which changed the type of
mapEitherT, resulting in

cabal install snap

aborting with a compilation failure compiling HeistNoClass.

The quick fix is to add

either == 3.0.*

to the .cabal file.

Cheers,
Daniel

PUT method simulation for digestive-functors form submission?

2013-01-23T18:45:57Z

Is there a way to simulate a PUT method for form submission in Snap /
digestive-functors (e.g. a hidden "_method" field)?
Additionally I wanted to point the form action at a resource (RESTlike), so
in the handler I'm binding a postAction attribute for the form, using
textSplice. Am I on the right track?

Map monad returning functions over a list, so I get a monad wrapped result list?

2013-01-19T14:19:04Z

I have a question about how to map functions over a list where each element
will return a Monad result - but I think I need one Monad wrapping for the
entire result list. Don't I need "Monad m => m [DataType]" instead of
"Monad m => [m DataType]"?
I think my problem is a generic one, but I'm toying around with

Application state without using snaplets

2013-01-13T02:21:24Z

Hi there,
I've been playing around with Snap lately and I want to use it to build a
little game server.
I need to hold some extra state in the Snap monad for my game. I've read
the tutorial on Snaplets, and it's clear how to store state using an App
data structure.
However, is it necessary to use Snaplets just to store a little bit of

HTTP client library using io-streams

2013-01-11T07:04:29Z

Hey,

I've been working on an HTTP client library.

The original idea (as described at
<[link]>) was to do something
that would be seamlessly compatible with Snap, specifically by re-using
its Request, Response types. That turned out to be a non-starter,

Heist: Use tag bindings from template level in splice level

2013-01-05T12:25:30Z

Dear Snap-List,

I've found a incompatibility of some code regarding Heist after
migrating it to Snap 0.10. In short, it seems that tags that are bound
in a template cannot be used in the splice level anymore, for example

<bind tag="foo">1234</bind>
<bar />

Random token mystery in Snap.Snaplet.Session.Common

2013-01-03T13:12:54Z

Dear Group,
Greetings and happy new year. I'm trying to upgrade my snap stuff
from 0.9 to 0.10 and have run across the following mystery. The
following code is basically just a copy of Snap.Snaplet.Session.Common
import qualified Snap.Snaplet.Session.Common as SSSC
{-
The rest of this, other than t1 and t2, is copied from

Performance turning and strictness annotations

2013-01-02T03:44:07Z

Happy New Year everyone.

Not really a Snap question, but inspired by the absolute wizard amount
of performance and cost centre annotations in the snap-server and
io-streams codebases:

I'm working on a library that uses io-streams. I (deliberately) didn't
do anything fancy when first writing it (well, other than using

How to trace snap's execution in GHCI debugger?

2012-12-31T20:58:28Z

Hi,

Debugger is my best friend in imperative programming language world.
Whenever I get an unfamiliar software with source code, I first load it
into debugger and trace the execution. It's the simplest and the most
efficient way for me to teach myself how the software works.

I want to have a better understanding of snap, I load its sample code up in

How does connection pooling work in snaplet-postgresql-simple?

2012-12-30T10:55:48Z

I've been developing a simple app with a lot of of concurrent AJAX
requests. My snaplet-sqlite-simple started hitting "database busy"
errors and so I've been on a bug hunt to find out why.

I came across the withPG function in Snap.Snaplet.PostgresqlSimple:

------------------------------ ------------------------------ ------------------

How do I access "MongoDB" from "SnapletLens app MongoDB"?

2012-12-24T14:38:33Z

I'm looking at the snaplet-mongodb-minimalistic library, and trying to get
it working with Snap 0.10.
There are some functions which take the type "Lens app (Snaplet MongoDB)",
which look to me as if they should now be "SnapletLens app MongoDB", but I
can't figure out how to obtain the MongoDB data from inside the SnapletLens.

Automatically logging in after new user registration

2012-12-23T19:57:09Z

Hi,

is there a recommended way to automatically login a user after he has
created a new user for himself with the registerUser handler?

Right now my code looks like:

handleFormSubmit = do
authUser <- registerUser "login" "password"
either (renderNewUserForm . Just) (const $ redirect "/") authUser

handling of pure exceptions

2012-12-20T16:06:38Z

Hi all,

I was looking into exception handling and came across the issue of pure
exceptions in arguments to lazy functions like 'writeLazyText'. I am aware
of the strict alternatives (e.g. 'writeText') but I wonder:

1. Is there a way to tell snap that I don't care for lazy streamed content

Problem with Snap.Snaplet.Auth.Backends.PostgresqlSimple

2012-12-18T14:40:50Z

Hi,
I'm having some trouble with getting postgresql auth backend to work.
First minor issue with testing was that connection to Postgresql server
does seem to work without password even though I have
local all all trust
in /etc/postgresql/9.1/pg_hba.con f
$ snap-test
no port specified, defaulting to port 8000

Highlighting TOC entries dynamically with heist

2012-12-15T12:44:32Z

Hei everybody,

we are trying to translate menu entry highlighting from php into
heist. we have a solution, but i wonder if there is a better one.

this is the php code:

| <ul>
| <li<?= preg_match('/about/',$pagePath ) ? ' class="current"' : ''; ?>>
| <a href="?page=about">About</a>

Failed to install snaplet-postgresql-simple

2012-12-13T15:33:18Z

Hi,
I'm having troubles to install snaplet-postgresql-simple on 64-bit Ubuntu
12.04LTS . ghc is version 7.4.1. Any ideas how to solve this?
Best Regards,
Tero Laitinen
$ cabal install snaplet-postgresql-simple
Resolving dependencies...
Downloading resource-pool-catchio-0.2.1.0. ..
Configuring resource-pool-catchio-0.2.1.0. ..

linking problem on OS X 10.8

2012-12-04T03:31:29Z

Hello,
I'm having trouble building Snap 9.2.2 on OS X 10.8 with ghc 7.4.1. It's
possible that this is a generic ghc issue, in which case I apologize for
asking about it here. When I do
$ rm -fr ~/.ghc
$ cabal install snap
The result (after compiling a bunch of dependencies) is:
Loading package directory-tree-0.11.0 ... linking ... done.

Using digestive functors to read dynamic number of inputs

2012-11-23T03:49:43Z

This is a digestive functors question more than Snap but this is my go-to
community for support:

Is it possible to use digestive functors to read a dynamic number of form
elements or subforms (and return a list of elements)? For example, say I
have a form to input dates (with day and time fields). I want to use

Snap, Snaplets, Templates confusion

2012-11-14T16:40:23Z

Hi
Sorry, but I'm struggling.
I have some dynamic pages created with a site :: Snap(), some Snap()
handler functions and Blaze for HTML generation.
I would like to use template files, but when I look at the Heist and
Snaplet examples, it all seems radically different.
I have managed to get a template server up, but with no dynamic content.

Do we still need regex-posix in 0.10?

2012-11-09T07:47:57Z

Hi guys,
looking at the last commit from Doug on the 0.10 branch, regex-posix
dependency has gone:

[link]

I still remember, though, that is needed for Snap.Test. Right?
In that case, we need to restore it back :)

Cheers,
A.

postgres snaplet- resources per stripe?

2012-11-07T03:25:31Z

Just getting started with the postgres snaplet, noticed this is the config
file:
maxResourcesPerStripe = 20
Not a postgres expert, so just wondering if anyone could a quick overview
on this parameter? Under what circumstances it should be raised or lowered?

SnapFramework.com Outage

2012-11-07T00:42:00Z

SnapFramework.com has been down for a while now. Not exactly the best
advertisement for a web server!

I first tried to peruse that site a week ago, and it's still down today. I
was initially curious whether the outage was due to Sandy, but most other
sites taken out by Sandy are back up and running.

Please help newbie get over the first hump

2012-11-06T09:31:38Z

Hello Snap users
I'm new to Snap and Haskell, and I should know better, but am profoundly
confused right now.
I would like to take the barebones application and use it to output an HTML
rendering of IO [String] that I have obtained from another module (which I
want to keep as-is), such that each String sits inside a <p></p> for

Using Data.Random in splices

2012-10-28T16:31:02Z

Dear Snappers,
I am trying to implement a splice that will shuffle its children. The
ideas is to have something like:
<shuffle>
<button>Button 1</button>
<button>Button 2</button>
<button>Button 3</button>
</shuffle>
and then return perhaps:
<button>Button 3</button>
<button>Button 1</button>
<button>Button 2</button>

[PATCH] make snap-loader-static work with ghc 7.6.1

2012-10-18T01:58:34Z

--- a/snap-loader-static.cabal
+++ b/snap-loader-static.cabal
@@ -25,7 +25,7 @@ Library

build-depends:
base >= 4 && < 5,
- template-haskell >= 2.2 && < 2.8
+ template-haskell >= 2.2 && < 2.9

if impl(ghc >= 6.12.0)
ghc-options: -Wall -fwarn-tabs -funbox-strict-fields -O2

[ANNOUNCE] snaplet-file-dialog-0.1.0.0 available on patch-tag

2012-10-05T10:07:09Z

Dear all,

the first version of the file dialog snaplet is out:

[link]

darcs get [link]

It was surprisingly simple to write, and using it is quite trivial.
Please check out the haddock documentation and the included sample

add mime types for video in snap

2012-10-05T03:48:10Z

Dear Snappers,

Any chance of adding:

( ".mp4" , "video/mp4" ),
( ".ogg" , "video/ogg" ),
( ".ogv" , "video/ogg" ),
( ".webm" , "video/webm" ),

to Snap.Util.FileServe so that my video files serve properly?

file dialog snaplet

2012-10-03T10:54:53Z

dear snap list,

my company has started to implement a sharepoint-style file transfer
area with upload, download, directory browsing, file attributes and
all that noise. it seems like this must have been done a million
times before in snap alone, but i couldn't find any code.

so we are tempted to factor this out of our code and publish it.

Kazu Yamamoto's improvements

2012-09-27T15:43:48Z

Are you guys following Kazu Yamamoto's performance fixes to
warp and simple-sendfile to take away tasks for improvement
in Snap? Most of it is common Unix httpd practice applied to
warp and simple-sendfile.

Snap.Snaplet.Auth: best practice for managing accounts

2012-09-24T16:11:39Z

Hi all,

the demo snap application allows you to create accounts from inside
the web app. This has several disadvantages, e.g. when you start the
portal, there are no accounts, and so there can't be an admin account,
and either everybody can create new accounts or nobody.

I am sure there is a simple way to handle this, but I can't find it.

Snap.Snaplet.Auth helper functions

2012-09-23T09:00:33Z

Hi all,

I'm developing a small web app using Snap with snaplet-auth and
snaplet-sqlite-simple [1].

While using some of the Snap.Snaplet.Auth helper functions, I came up
with a couple of suggestions.

1. Helper function requireUser should call the "good" handler with an AuthUser

requireUser :: Lens b (Snaplet (AuthManager b))

Logging errors to stdout?

2012-09-21T05:43:50Z

Hi,

Is there a way to make Snap output its logs on stdout instead of by
default printing to access.log and error.log? It's a bit inconvenient
to go less'ing or tail'ing files when doing development.

thanks,

Janne

[Snap] Argument Substitution in Heist Templates with Splices

2012-09-20T19:00:44Z

Hello,

the following program demonstrates that arguments in Heist templates
are sometimes not substituted in presence of splices:

{-# LANGUAGE OverloadedStrings #-}

import Blaze.ByteString.Builder (toByteString)
import qualified Data.ByteString.Char8 as BS
import Data.Functor ((<$>))

can't install snaplet-hdbc, duplicate type signature

2012-09-19T02:17:21Z

Hey all,
I'm relatively new to Haskell, been learning for the last 6 months or so
and had a class in university that covered the basics. So I decided I'd
give the Snap framework a spin on my machine. It's a relatively new machine
so this is a fresh install of Haskell (GHC 7.4.1) on Ubuntu 12.04. I

Help me to get the general overview of the testing workflow

2012-09-17T13:10:34Z

Hi,
I'm basically trying to help with snap, but the project size is huge and
it's easy to get overwhelmed.
I've fixed a little bug (see issue #30 on github) and I would like to test
the code I wrote, but I'm struggling with the test setup:
a) I use hsenv to manage my sandboxed environment: by default, it build

Interaction between getPostParam and file uploads

2012-09-14T15:56:19Z

I've had a problem where getPostParam/getParam returns Nothing for a CSRF
token passed to Snap as a hidden form parameter when dealing with file
uploads. I've included a minimal-ish demonstration of the behavior.

Now, it makes sense that Snap would not find the "comment" field until
after the file upload is completed, because the browser sends the comment