Hoogle Search

Note that Stackage only displays results for the latest LTS and Nightly snapshot. Learn more.

fromForm :: FromForm a => Form -> Either Text a

http-api-data Web.FormUrlEncoded

Parse Form into a value.
genericFromForm :: (Generic a, GFromForm a (Rep a)) => FormOptions -> Form -> Either Text a

http-api-data Web.FormUrlEncoded

A Generic-based implementation of fromForm. This is used as a default implementation in FromForm. Note that this only works for records (i.e. product data types with named fields):
```
data Person = Person
{ name :: String
, age  :: Int
} deriving (Generic)
```
In this implementation each field's value gets decoded using parseQueryParam. Two field types are exceptions:
- for values of type Maybe a an entry is parsed if present in the Form and the is decoded with parseQueryParam; if no entry is present result is Nothing;
- for values of type [a] (except [Char]) all entries are parsed to produce a list of parsed values;
Here's an example:
```
data Post = Post
{ title    :: String
, subtitle :: Maybe String
, comments :: [String]
} deriving (Generic, Show)

instance FromForm Post
```
```
>>> urlDecodeAsForm "comments=Nice%20post%21&comments=%2B1&title=Test" :: Either Text Post
Right (Post {title = "Test", subtitle = Nothing, comments = ["Nice post!","+1"]})
```
genericToForm :: (Generic a, GToForm a (Rep a)) => FormOptions -> a -> Form

http-api-data Web.FormUrlEncoded

A Generic-based implementation of toForm. This is used as a default implementation in ToForm. Note that this only works for records (i.e. product data types with named fields):
```
data Person = Person
{ name :: String
, age  :: Int
} deriving (Generic)
```
In this implementation each field's value gets encoded using toQueryParam. Two field types are exceptions:
- for values of type Maybe a an entry is added to the Form only when it is Just x and the encoded value is toQueryParam x; Nothing values are omitted from the Form;
- for values of type [a] (except [Char]) an entry is added for every item in the list; if the list is empty no entries are added to the Form;
Here's an example:
```
data Post = Post
{ title    :: String
, subtitle :: Maybe String
, comments :: [String]
} deriving (Generic, Show)

instance ToForm Post
```
```
>>> urlEncodeAsFormStable Post { title = "Test", subtitle = Nothing, comments = ["Nice post!", "+1"] }
"comments=Nice%20post%21&comments=%2B1&title=Test"
```
parseFormKey :: FromFormKey k => Text -> Either Text k

http-api-data Web.FormUrlEncoded

Parse a key of a Form.
toForm :: ToForm a => a -> Form

http-api-data Web.FormUrlEncoded

Convert a value into Form.
toFormKey :: ToFormKey k => k -> Text

http-api-data Web.FormUrlEncoded

Render a key for a Form.
unForm :: Form -> HashMap Text [Text]

http-api-data Web.FormUrlEncoded

No documentation available.
urlDecodeAsForm :: FromForm a => ByteString -> Either Text a

http-api-data Web.FormUrlEncoded

This is a convenience function for decoding a application/x-www-form-urlencoded ByteString directly to a datatype that has an instance of FromForm. This is effectively fromForm <=< urlDecodeForm.
```
>>> urlDecodeAsForm "name=Dennis&age=22" :: Either Text Person
Right (Person {name = "Dennis", age = 22})
```

urlDecodeForm :: ByteString -> Either Text Form

http-api-data	Web.FormUrlEncoded

Decode an application/x-www-form-urlencoded ByteString to a Form. Key-value pairs get decoded normally:

>>> urlDecodeForm "name=Greg&lastname=Weber"
Right (fromList [("lastname","Weber"),("name","Greg")])

Keys with no values get decoded to pairs with empty values.

>>> urlDecodeForm "is_test"
Right (fromList [("is_test","")])

Empty keys are allowed:

>>> urlDecodeForm "=foobar"
Right (fromList [("","foobar")])

The empty string gets decoded into an empty Form:

>>> urlDecodeForm ""
Right (fromList [])

Everything is un-escaped with unEscapeString:

>>> urlDecodeForm "fullname=Andres%20L%C3%B6h"
Right (fromList [("fullname","Andres L\246h")])

Improperly formed strings result in an error:

>>> urlDecodeForm "this=has=too=many=equals"
Left "not a valid pair: this=has=too=many=equals"

urlEncodeAsForm :: ToForm a => a -> ByteString

http-api-data Web.FormUrlEncoded

This is a convenience function for encoding a datatype that has instance of ToForm directly to a application/x-www-form-urlencoded ByteString. This is effectively urlEncodeForm . toForm. _NOTE:_ this encoding is unstable and may result in different key order (but not values). For a stable encoding see urlEncodeAsFormStable.

Page 500 of many | Previous | Next