Safe Haskell	Safe-Inferred
Language	Haskell2010

Hypermedia.Datastar.PatchSignals

Description

Signals are Datastar's reactive state — key-value pairs that live in the browser and drive the UI. The server can update signals at any time by sending a datastar-patch-signals event.

Signal patching uses JSON Merge Patch semantics: set a key to update it, set a key to null to remove it, and omit a key to leave it unchanged.

sendPatchSignals gen (patchSignals "{\"count\": 42}")

To set initial state without overwriting values the user may have already changed (e.g. form inputs), use psOnlyIfMissing:

sendPatchSignals gen
  (patchSignals "{\"name\": \"default\"}")
    { psOnlyIfMissing = True }

Synopsis

data PatchSignals = PatchSignals {
- psSignals :: Text
- psOnlyIfMissing :: Bool
- psEventId :: Maybe Text
- psRetryDuration :: Int
}
patchSignals :: Text -> PatchSignals
toDatastarEvent :: PatchSignals -> DatastarEvent

Documentation

data PatchSignals Source #

Configuration for a datastar-patch-signals SSE event.

Construct values with patchSignals, then customise with record updates.

Constructors

PatchSignals

Fields

psSignals :: Text
JSON object containing the signal values to patch. Uses JSON Merge Patch semantics: set a key to update it, set to null to remove it.
psOnlyIfMissing :: Bool
When True, signal values are only set if the key doesn't already exist in the browser's store. Useful for setting initial state that shouldn't overwrite user changes (e.g. form input defaults). Default: False.
psEventId :: Maybe Text
Optional SSE event ID for reconnection. See PatchElements for details.
psRetryDuration :: Int
SSE retry interval in milliseconds. Default: 1000.

Instances

Instances details

Show PatchSignals Source #
Instance details Defined in Hypermedia.Datastar.PatchSignals Methods showsPrec :: Int -> PatchSignals -> ShowS # show :: PatchSignals -> String # showList :: [PatchSignals] -> ShowS #
Eq PatchSignals Source #
Instance details Defined in Hypermedia.Datastar.PatchSignals Methods (==) :: PatchSignals -> PatchSignals -> Bool # (/=) :: PatchSignals -> PatchSignals -> Bool #

patchSignals :: Text -> PatchSignals Source #

Build a PatchSignals event with sensible defaults.

The argument is a JSON object (as Text) describing the signals to update.

patchSignals "{\"count\": 42, \"label\": \"hello\"}"

toDatastarEvent :: PatchSignals -> DatastarEvent Source #