Beispiel #1
0
func ExampleIterator_Cursor() {
	ctx := context.Background()
	client, _ := datastore.NewClient(ctx, "my-proj")
	cursorStr := ""
	// [START cursor_paging]
	const pageSize = 5
	query := datastore.NewQuery("Tasks").Limit(pageSize)
	if cursorStr != "" {
		cursor, err := datastore.DecodeCursor(cursorStr)
		if err != nil {
			log.Fatalf("Bad cursor %q: %v", cursorStr, err)
		}
		query = query.Start(cursor)
	}

	// Read the tasks.
	var tasks []Task
	var task Task
	it := client.Run(ctx, query)
	_, err := it.Next(&task)
	for err == nil {
		tasks = append(tasks, task)
		_, err = it.Next(&task)
	}
	if err != datastore.Done {
		log.Fatalf("Failed fetching results: %v", err)
	}

	// Get the cursor for the next page of results.
	nextCursor, err := it.Cursor()
	// [END cursor_paging]
	_ = err        // Check the error.
	_ = nextCursor // Use nextCursor.String as the next page's token.
}
Beispiel #2
0
func ExampleDecodeCursor() {
	// See Query.Start for a fuller example of DecodeCursor.
	// getCursor represents a function that returns a cursor from a previous
	// iteration in string form.
	cursorString := getCursor()
	cursor, err := datastore.DecodeCursor(cursorString)
	if err != nil {
		// TODO: Handle error.
	}
	_ = cursor // TODO: Use the cursor with Query.Start or Query.End.
}
Beispiel #3
0
func ExampleQuery_Start() {
	// This example demonstrates how to use cursors and Query.Start
	// to resume an iteration.
	ctx := context.Background()
	client, err := datastore.NewClient(ctx, "project-id")
	if err != nil {
		// TODO: Handle error.
	}
	// getCursor represents a function that returns a cursor from a previous
	// iteration in string form.
	cursorString := getCursor()
	cursor, err := datastore.DecodeCursor(cursorString)
	if err != nil {
		// TODO: Handle error.
	}
	it := client.Run(ctx, datastore.NewQuery("Post").Start(cursor))
	_ = it // TODO: Use iterator.
}