Database.CouchDB.Conduit.Explicit

Explicit methods for CouchDB documents. Documents represents in "good old" aeson manner through ToJSON and FromJSON.

 {-# LANGUAGE OverloadedStrings, ScopedTypeVariables #-}

 import Control.Applicative ((<$>), (<*>))
 import Control.Monad.IO.Class (liftIO)
 import Data.Aeson
 import Database.CouchDB.Conduit
 import Database.CouchDB.Conduit.Explicit

 -- | Our doc with instances
 data D = D { f1 :: Int, f2 :: String } deriving (Show)
 
 instance FromJSON D where
    parseJSON (Object v) = D <$> v .: "f1" <*> v .: "f2"
    parseJSON _          = mzero

 instance ToJSON D where
    toJSON (D f1 f2) = object ["f1" .= f1, "f2" .= f2]
 
 runCouch def $ do
    -- Put new doc and update it
    rev1 <- couchPut "mydb" "my-doc1" "" [] $ D 123 "str"         
    rev2 <- couchPut "mydb" "my-doc1" rev1 [] $ D 1234 "another"

    -- get it and print
    (rev3, d1 :: D) <- couchGet "mydb" "my-doc1" [] 
    liftIO $ print d1

    -- update it in brute-force manner    
    couchPut' "mydb" "my-doc1" [] $ D 12345 "third"    -- notice - no rev
    
    -- get revision and delete
    rev3 <- couchRev "mydb" "my-doc1"
    couchDelete "mydb" "my-doc1" rev3

For details of types see Data.Aeson. To work with documents in generic manner, look at Database.CouchDB.Conduit.Generic.

Accessing documents

couchGet

Arguments

:: (MonadCouch m, FromJSON a)

=> Path

Database

-> Path

Document path

-> Query

Query

-> m (Revision, a)

Load a single ToJSON object with Revision from couch DB.

Manipulating documents

couchPut

Arguments

:: (MonadCouch m, ToJSON a)

=> Path

Database

-> Path

Document path

-> Revision

Document revision. For new docs provide empty string.

-> Query

Query arguments.

-> a

The object to store.

-> m Revision

Put an FromJSON object in Couch DB with revision, returning the new Revision.

couchPut_

Arguments

:: (MonadCouch m, ToJSON a)

=> Path

Database

-> Path

Document path

-> Query

Query arguments.

-> a

The object to store.

-> m Revision

"Don't care" version of couchPut. Creates document only in its absence.

couchPut'

Arguments

:: (MonadCouch m, ToJSON a)

=> Path

Database

-> Path

Document path

-> Query

Query arguments.

-> a

The object to store.

-> m Revision

Brute force version of couchPut. Creates a document regardless of presence.

Working with views

toType :: (MonadResource m, FromJSON a) => Conduit Value m a

Convert CouchDB view row or row value from Database.CouchDB.Conduit.View to concrete FromJSON type.

 res <- couchView "mydesign" "myview" [] $ rowValue =$= toType =$ consume