stew/* Packages / 14.11

🌐 stew/net

The stew/net package is a type-safe wrapper around the browser's Fetch API, allowing asynchronous HTTP requests with synchronous Go syntax.

Concept: Simplifying Asynchrony

In JavaScript, fetch returns Promises (Promise) requiring .then() or await. In Stew, we use a synchronization bridge via Go channels.

Internal mechanism: When a net.Get call is made, the Go-routine is paused (blocked on a channel) while the browser performs the request. As soon as the JS Promise is resolved, the result is injected back into the channel, transparently unblocking the Go-routine.

Typed Requests (Generics)

Use Go generics to automatically deserialize JSON into your own structures.

<goscript client>
    import "stew/net"

    type User struct {
        Name  string `json:"name"`
        Email string `json:"email"`
    }

    loadData := func() {
        user, err := net.Get[User]("https://api.example.com/me")
        if err != nil {
            fmt.Println("Error:", err)
            return
        }
        fmt.Println("User:", user.Name)
    }
</goscript>

Supported Methods

net.Get[T](url)
Retrieves a resource.
net.Post[T](url, body)
Sends data (JSON auto-marshaling).
net.Put[T](url, body)
Updates an existing resource entirely.
net.Patch[T](url, body)
Partially updates a resource.
net.Delete[T](url)
Removes a resource.
net.Fetch(url, opts)
Raw Fetch API access (Headers, etc.).

Reactive Observation: net.Watch

Creates a Signal that automatically updates at a regular interval. Ideal for dashboards or live data feeds. 

<goscript client>
    import "stew/net"
    import "time"

    // Poll the API every 5 seconds
    stats := net.Watch[Stats]("https://api.site.com/stats", 5*time.Second)
</goscript>

<p>Current visitors: {{ stats.Get().Visits }}</p>

Network State: net.IsLoading

A global bool Signal that becomes true whenever a stew/net request is in progress. 

<goscript client>
    import "stew/net"
</goscript>

{{ if net.IsLoading.Get() }}
    <div class="spinner">Loading...</div>
{{ end }}