Datastar Go SDK

The SDK allows you to interact with Datastar clients by reading signals from incoming requests and sending Server-Sent Events (SSE) to patch the DOM, update client-side state (signals), execute scripts, or redirect the browser.

Reading Signals

Use datastar.ReadSignals(r, store) to decode signals sent from the client into a Go struct. The struct fields must have appropriate json tags.

Managing the Client via SSE

Initialize an SSE writer using datastar.NewSSE(w, r). Once initialized, you can perform the following actions:

• Patch Elements: Update specific DOM elements using sse.PatchElements(html).
• Remove Elements: Delete elements from the DOM using sse.RemoveElement(selector).
• Update Signals: Update client-side state using sse.MarshalAndPatchSignals(map[string]any).
• Execute JavaScript: Run arbitrary JS in the browser using sse.ExecuteScript(script).
• Redirect: Navigate the browser using sse.Redirect(url).

import (
    "net/http"
    "github.com/starfederation/datastar-go/datastar"
)

// Define a struct to hold client signals
type Store struct {
    Message string `json:"message"`
    Count   int    `json:"count"`
}

func handler(w http.ResponseWriter, r *http.Request) {
    // 1. Read signals from the request
    store := &Store{}
    if err := datastar.ReadSignals(r, store); err != nil {
        http.Error(w, err.Error(), http.StatusBadRequest)
        return
    }

    // 2. Create a Server-Sent Event writer
    sse := datastar.NewSSE(w, r)

    // 3. Perform actions
    sse.PatchElements(`<div id="output">Hello from Datastar!</div>`)
    sse.RemoveElement("#temporary-element")
    sse.MarshalAndPatchSignals(map[string]any{
        "message": "Updated message",
        "count":   store.Count + 1,
    })
    sse.ExecuteScript(`console.log("Hello from server!")`)
    sse.Redirect("/new-page")
}