Pencil.Env

Functions that manipulate the environment.

Documentation

data Value

Represents the data types found in an environment.

This includes at least Aeson Value types, plus other useful ones.

Constructors

VNull

VText Text

VBool Bool

VDateTime UTCTime

VArray [Value]

VEnvList [Env]

VNodes [PNode]

Instances

Eq Value

Defined in Pencil.Env.Internal

Methods

(==) :: Value -> Value -> Bool

(/=) :: Value -> Value -> Bool

Show Value

Defined in Pencil.Env.Internal

Methods

showsPrec :: Int -> Value -> ShowS

show :: Value -> String

showList :: [Value] -> ShowS

withEnv :: Env -> PencilApp a -> PencilApp a

Runs the computation with the given environment. This is useful when you want to render a Page or Structure with a modified environment.

withEnv (insertText "newvar" "newval" env) (render page)

Alternatively, use local, which is re-exported in the Pencil module.

insert

Arguments

:: Text

Environment variable name.

-> Value

Value to insert.

-> Env

Environment to modify.

-> Env

Inserts Value into the given Env.

insertText

Arguments

:: Text

Environment variable name.

-> Text

Text to insert.

-> Env

Environment to modify.

-> Env

Inserts text into the given Env.

env <- asks getEnv
insertText "title" "My Awesome Website" env

adjust

Arguments

:: (Value -> Value)

-> Text

Environment variable name.

-> Env

-> Env

Modifies a variable in the given environment.

merge :: Env -> Env -> Env

Merges two Envs together, biased towards the left-hand Env on duplicates.

toText :: Value -> Text

Renders environment value for human consumption. This is the default one.

toTextRss :: Value -> Text

A version of toText that renders Value acceptable for an RSS feed.

• Dates are rendered in the RFC 822 format.
• Everything else defaults to the toText implementation.

You'll probably want to also use escapeXml to render an RSS feed.

arrayContainsText :: Text -> Value -> Bool

Returns true if the given Value is a VArray that contains the given text.

dateOrdering :: Value -> Value -> Ordering

Sort by newest first.

maybeOrdering :: (Value -> Value -> Ordering) -> Maybe Value -> Maybe Value -> Ordering

Defines an ordering for possibly-missing Value. Nothings are ordered last.