Update the Wallet

The fact that Wollet does have access to internet is a deliberate choice.
This allows Wollet to work offline, where they can generate addresses.

The connection is handled by a specific component, a Blockchain Client.
Blockchain clients connect to the specified server a fetch the wallet data from the blockchain.

LWK currently support 3 types of servers:

• Electrum Servers
• Esplora Servers
• Waterfalls Servers

To delve into their differences and strength points see our dedicated section.

Create a Client

In this guide we will use an EsploraClient.

You can create a new client with EsploraClient::new(), specifying the URL of the service.

Scan the Blockchain

Given a Wollet you can call EsploraClient::full_scan(),
which performs a series of network calls that scan the blockchain to find transactions relevant for the wallet.

EsploraClient::full_scan() has a stopping mechanisms that relies on BIP44 GAP LIMIT.
This might not fit every use cases.
In case you have large sequences of consecutive unused addresses you can use
EsploraClient::full_scan_to_index().

Apply the Update

EsploraClient::full_scan() fetches, parses, (locally) unblind and serialized the fetched data in returned value, an Update.
The Update can be applied to the Wollet using Wollet::apply_update().

After applying the update the wollet data will include the new transaction downloaded,
for instance more transactions can be returned and balance can increase (or decrease).

use lwk_wollet::clients::blocking::EsploraClient;
// let url = "https://blockstream.info/liquidtestnet/api";
// let url = "https://blockstream.info/liquid/api";

let mut client = EsploraClient::new(&url, network)?;

if let Some(update) = client.full_scan(&wollet)? {
    wollet.apply_update(update)?;
}

url = "https://blockstream.info/liquidtestnet/api"
client = EsploraClient(url, network)

update = client.full_scan(wollet)
wollet.apply_update(update)

const url = "https://blockstream.info/liquidtestnet/api";
const client = new lwk.EsploraClient(network, url, true, 4, false);

const update = await client.fullScan(wollet);
if (update) {
    wollet.applyUpdate(update);
}

	url := "https://blockstream.info/liquidtestnet/api"
	client, err := lwk.NewEsploraClient(url, network)
	if err != nil {
		log.Fatal(err)
	}

	update, err := client.FullScan(wollet)
	if err != nil {
		log.Fatal(err)
	}
	if update != nil {
		if err := wollet.ApplyUpdate(*update); err != nil {
			log.Fatal(err)
		}
	}

Next: Create a transaction