Flash Messages Example

This example demonstrates flash messages in LiveTemplate - page-level notifications that show once and clear after each action.

Running

cd examples/flash-messages
go run .

Then open http://localhost:8080

Flash Message Types

Setting Flash Messages (Controller)

func (c *Controller) MyAction(state State, ctx *livetemplate.Context) (State, error) {
    // Success notification
    ctx.SetFlash("success", "Item added successfully!")

    // Error notification
    ctx.SetFlash("error", "Failed to save changes")

    // Warning notification
    ctx.SetFlash("warning", "Item already exists")

    // Info notification
    ctx.SetFlash("info", "Processing complete")

    return state, nil
}

Reading Flash Messages (Template)

<!-- Check if any flash exists -->
{{if .lvt.HasAnyFlash}}
<div id="flash-messages">

    <!-- Check specific flash type -->
    {{if .lvt.HasFlash "success"}}
    <div class="alert alert-success">{{.lvt.Flash "success"}}</div>
    {{end}}

    {{if .lvt.HasFlash "error"}}
    <div class="alert alert-error">{{.lvt.Flash "error"}}</div>
    {{end}}

</div>
{{end}}

Flash vs Field Errors

Key Behaviors

1. Show Once: Flash messages are cleared after each action response
2. Per-Connection: Not shared across browser tabs
3. No Persistence: Don't survive page refresh or WebSocket reconnects
4. Don't Block Success: Unlike field errors, flash messages don't set Success: false

Available Template Helpers