VKHS

VKHS provides access to Vkontakte social network, popular mainly in Russia. Library can be used to login into the network as a standalone application (OAuth implicit flow as they call it). Having the access token, it is possible to call various API methods to query audio files or retrieve wall messages. For now, vkhs offers limited error detection and no captcha support.

Features

• Provide access to VK API. Interface options include: VK monad and vkq command line tool.
• Use HTTPS protocol.
• Solve login form interaction, may be used to operate new/disposable VK accounts.
• VK monad is an interruptable coroutine. The superwiser supports ondemand re-login, and may be used for long-running tasks.
• Project includes a set of Web.VKHS.API.Simple wrappers designed to be copied into runhaskell scripts and tweaked according to ones need.

Issues

• Still no support for captchas, one probably should hack defaultSuperwiser and add them
• Network connection timeout is not handled by superwiser
• Minor issues here and there. Use git grep FIXME to find them
• File uploading still not functioning

Installing

Installing from Hackage

In order to install VKHS, one typically should do the following

$ cabal update
$ cabal install VKHS

Note, that VKHS uses curlhs and should be linked with libcurl.so. Normally, cabal handles it without problems.

Installing from source

$ git clone https://github.com/grwlf/vkhs
$ cd vkhs
$ cabal install

Developing using Nix

The author of this project uses Nix as a main development platform. Typical development procedure includes the following steps:

$ git clone https://github.com/grwlf/vkhs
$ cd vkhs
$
$ nix-shell

  .. Entering Nix shell environment

$ ghci -isrc:app/vkq:app/common
$ exit

  ..  Now exiting from the Nix shell

$ nix-build

The default.nix file contain Nix expression describing the environment

Building ctags file

./mktags.sh script may be used to build ctags file. It used haskdogs tool, which should be installed from Hackage.

$ haskdogs

VKQ command line application

vkq is a command line tool which demonstrates API usage. It can be used for logging in, downloading music and reading wall messages. Call vkq --help or vkq --help [command] to read online help.

Log in to VK

Here is an example session: Login first

$ vkq login user@mail.org pass123
d8a41221616ef5ba19537125dc0349bad9d529fa15314ad765911726fe98b15185ac41a7ca2c62f3bf4b9

VKQ returns three values. First one is an access token required to execute all API requests. vkq tries to reads it from VKQ_ACCESS_TOKEN environment variable or from .vkhs-access-token file (may be changed using options).

$ export VKQ_ACCESS_TOKEN=d785932b871f096bd73aac6a35d7a7c469dd788d796463a871e5beb5c61bc6c96788ec2

VKQ may cache the access tokein into a state file:

$ vkq login --access-token-file=.access-token

.. VKQ will ask for email/password and cache the access token

$ vkq call groups.search q=Beatles --pretty --access-token-file=.access-token

Latest versions of the library have --access-token-flag option enabled by default. Set it to empty value to disable the caching feature.

Performing custom API calls

vkq allows user to call arbitrary API method. The format is as follows:

Usage: vkq call [--verbose] [--req-per-sec N] [--interactive] [--appid APPID]
                [--user USER] [--pass PASS] [-a ACCESS_TOKEN] METHOD PARAMS

For example, lets call ausio.search method to get some Beatles records:

$ vkq call group.search q=Beatles --pretty

  { "response": [
    614751,
    {
        "lyrics_id": "6604412",
        "url": "http://cs1-36v4.vk-cdn.net/p16/59674dd8717db2.mp3?extra=k0s2ja3l6pq6aIDOEW5y5XUCs2--JLX9wZpzOT3iuSnZPR-DNhJSF075NUhICB_szMOKKlVJFFlqLlg691q6cKhwiGZgTRU1oAimXzXY396cfNAHnotc8--7w-0xnvoPK6qVoI8",
        "aid": 85031440,
        "title": "Twist and Shout  ",
        "genre": 1,
        "owner_id": 9559206,
        "duration": 156,
        "artist": "The Beatles"
    },
...

VKHS library/runhaskell mode

Starting from 1.7.2 the library supports RunHaskell-mode. Consider the following example:

#!/usr/bin/env runhaskell
{-# LANGUAGE RecordWildCards #-}

import Prelude ()
import Web.VKHS
import Web.VKHS.Imports

main :: IO ()
main = runVK_ defaultOptions $ do
  Sized cnt cs <- getCountries
  forM_ cs $ \Country{..} -> do
    liftIO $ putStrLn co_title

When executed, the program asks for login/password and outputs list of countries known to VK. getCountries and several other methods are defined in Web.VKHS.API.Simple. vkq application may be used as a more elaborated example.

Debugging

Verbosity may be increased using --verbose flag or o_verbose field of GenericOptions. Login automata saves latest.html file during operation.

References

• Implicit-flow authentication, see documentation in Russian for details
• VK API documentation

License

BSD3 license

Copyright (c) 2014, Sergey Mironov grrwlf@gmail.com