# `@ldo/connected-nextgraph`

The `@ldo/connected-nextgraph` library allows you to integrate [NextGraph](https://nextgraph.org) with the [LDO](https://ldo.js.org) ecosystem. It provides a `ConnectedLdoDataset` that manages RDF data across decentralized NextGraph resources with real-time synchronization and read/write capabilities.

## Installation

First, install the required libraries:

```bash
npm install nextgraph @ldo/connected-nextgraph
```

## Usage:

### 1. Setup: Create a ConnectedLdoDataset

```ts
import { createNextGraphLdoDataset } from "@ldo/connected-nextgraph";

// Create the dataset
const ldoDataset = createNextGraphLdoDataset();
```

### 2. Connect to a NextGraph Wallet Session

Before you can create or access resources, you need an active session:

```ts
import ng from "nextgraph";

// Open your nextgraph wallet
const openedWallet = await ng.wallet_open_with_mnemonic_words(
  walletBinary,
  mnemonic,
  [1, 2, 3, 4]
);

// Start a session
const session = await ng.session_in_memory_start(
  openedWallet.V0.wallet_id,
  openedWallet.V0.personal_site
);
```

---

### 3. Link Your Dataset to the NextGraph Session

```ts
ldoDataset.setContext("nextgraph", {
  sessionId: session.session_id
});
```

### 4. Create a Resource

To create a new resource in your store:

```ts
const resource = await ldoDataset.createResource("nextgraph");
if (!resource.isError) {
  console.log("Created resource:", resource.uri);
}
```

### 5. Read and Monitor a Resource**

#### Read Existing Resource

```ts
const resource = ldoDataset.getResource(existingUri);
const readResult = await resource.read();

if (!readResult.isError) {
  console.log("Resource loaded!", readResult.type);
}
```

#### Read Only If Unfetched

Avoid redundant fetches:

```ts
const readResult = await resource.readIfUnfetched();
```

#### Subscribe to Notifications

```ts
const unsubscribeId = await resource.subscribeToNotifications();
await resource.unsubscribeFromNotification(unsubscribeId);
await resource.unsubscribeFromAllNotifications();
```

---

### 6. Write Data to a Resource

You can write RDF data to a resource using `update()`:

```ts
import { parseRdf } from "@ldo/ldo";

const ttlData = `
@prefix foaf: <http://xmlns.com/foaf/0.1/> .
<#spiderman> a foaf:Person ; foaf:name "Spiderman" .
`;

const triples = await parseRdf(ttlData);

await resource.update({
  added: triples,
  removed: undefined
});
```

## Sponsorship
This project was made possible by a grant from NGI Zero Entrust via nlnet. Learn more on the [NLnet project page](https://nlnet.nl/project/SolidUsableApps/).

[<img src="https://nlnet.nl/logo/banner.png" alt="nlnet foundation logo" width="300" />](https://nlnet.nl/)
[<img src="https://nlnet.nl/image/logos/NGI0Entrust_tag.svg" alt="NGI Zero Entrust Logo" width="300" />](https://nlnet.nl/)

## Liscense
MIT