Datastar Racket SDK🔗ℹ

1 Usage🔗ℹ

Example usage (adapted from the Datastar Go SDK docs)

#lang racket

(require web-server/dispatch

web-server/servlet-dispatch

web-server/http

datastar

json)

(struct store (message count) #:transparent)

(define (handler req)

; Read signals from the request

(define signals-data (read-signals req))

(define current-store

(store (hash-ref signals-data 'message "")

(hash-ref signals-data 'count 0)))

; Create a Server-Sent Event response

(datastar-response

(list

; Patch elements in the DOM

(patch-elements "<div id=\"output\">Hello from Datastar!</div>")

; Remove elements from the DOM

(remove-elements "#temporary-element")

; Patch signals (update client-side state)

(patch-signals (hash 'message "Updated message"

'count (+ (store-count current-store) 1)))

; Execute JavaScript in the browser

(execute-script "console.log(\"Hello from server!\")")

; Redirect the browser

(redirect "/new-page"))))

For more advanced usage with streaming updates, you can use generators:

(define (streaming-handler req)

(datastar-response

(in-generator

(let loop ([i 0])

(when (< i 10)

(yield (patch-signals (hash 'counter i)))

(yield (patch-elements

(format "<div id=\"counter\">Count: ~a</div>" i)))

(sleep 1)

(loop (+ i 1)))))))

For more examples, see the examples directory on GitHub.

2 Methods🔗ℹ

3 Constants🔗ℹ