Safe Haskell	Safe-Infered

Yesod.Json

Contents

Convert from a JSON value
Convert to a JSON value
Produce JSON values
Convenience functions

Synopsis

Convert from a JSON value

defaultLayoutJson Source

Arguments

:: (Yesod master, ToJSON a)
=> GWidget sub master ()	HTML
-> a	JSON
-> GHandler sub master RepHtmlJson

Provide both an HTML and JSON representation for a piece of data, using the default layout for the HTML output (defaultLayout).

Since: 0.3.0

jsonToRepJson :: ToJSON a => a -> GHandler sub master RepJson Source

Wraps a data type in a RepJson. The data type must support conversion to JSON via ToJSON.

Since: 0.3.0

Convert to a JSON value

parseJsonBody :: FromJSON a => GHandler sub master (Result a)Source

Parse the request body to a data type as a JSON value. The data type must support conversion from JSON via FromJSON. If you want the raw JSON value, just ask for a Result Value.

Since: 0.3.0

parseJsonBody_ :: FromJSON a => GHandler sub master aSource

Same as parseJsonBody, but return an invalid args response on a parse error.

Produce JSON values

data Value

A JSON value represented as a Haskell value.

Constructors

Object !Object
Array !Array
String !Text
Number !Number
Bool !Bool
Null

Instances

Eq Value
Show Value
Typeable Value
IsString Value
ToJSON Value
FromJSON Value
NFData Value
Hashable Value
ToJavascript Value
ToContent Value

object :: ToJSON a => [(Text, a)] -> Value Source

Convert a list of pairs to an Object.

array :: ToJSON a => [a] -> Value Source

Convert a list of values to an Array.

(.=) :: ToJSON a => Text -> a -> Pair

Construct a Pair from a key and a value.

Convenience functions

jsonOrRedirect Source

Arguments

:: (Yesod master, ToJSON a)
=> Route master	Redirect target
-> a	Data to send via JSON
-> GHandler sub master RepJson

jsonOrRedirect simplifies the scenario where a POST handler sends a different response based on Accept headers:

200 with JSON data if the client prefers application/json (e.g. AJAX, see acceptsJSON).
3xx otherwise, following the PRG pattern.

acceptsJson :: Yesod master => GHandler sub master Bool Source

Returns True if the client prefers application/json as indicated by the Accept HTTP header.