API Integration

Most applications need to communicate with external services. In rfw, the HTTP API provides helpers to fetch JSON, handle loading states, and cache responses.

Fetching JSON

Use FetchJSON to retrieve data and unmarshal it into a Go struct:

var todo struct {
    Title string `json:"title"`
}

if err := http.FetchJSON("https://jsonplaceholder.typicode.com/todos/1", &todo); err != nil {
    if errors.Is(err, http.ErrPending) {
        // show loading UI
    } else {
        // handle fetch error
    }
}

If the request is pending, ErrPending is returned so you can display a loading state. On success, the struct is populated with the response.

Updating State from a Request

A common pattern is to fetch asynchronously and update a store:

go func() {
    var todo struct {
        Title string `json:"title"`
    }
    if err := http.FetchJSON("https://jsonplaceholder.typicode.com/todos/1", &todo); err != nil {
        store.Set("apiData", err.Error())
        return
    }
    store.Set("apiData", todo.Title)
}()

This updates the apiData store with either the title or an error string.

When Not to Use

Skip network calls when:

• The data is static and bundled in your app.
  
• You need offline-first behavior.
  

data := loadFromLocalFile()
store.Set("apiData", data)

Interactive Example

@include:ExampleFrame:{code:“/examples/components/api_integration_component.go”, uri:“/examples/api”}