diffusion

import * as diffusion from 'diffusion'; async function runDiffusionClient() { const host = process.env.DIFFUSION_HOST ?? 'ws://localhost:8080'; const principal = process.env.DIFFUSION_PRINCIPAL ?? 'admin'; const credentials = process.env.DIFFUSION_CREDENTIALS ?? 'password'; const topicPath = 'my/topic/path'; let session: diffusion.Session | undefined; try { session = await diffusion.connect({ host: host, principal: principal, credentials: credentials, // secure: true // Uncomment for WSS connections }); console.log(`Connected to Diffusion server: ${session.sessionId}`); // Create a value stream for a JSON topic session.addStream(topicPath, diffusion.datatypes.json()).on( 'value', (topic, spec, newValue, oldValue) => { console.log(`Update for ${topic}: ${JSON.stringify(newValue?.get())}`); } ); // Subscribe to the topic await session.select(topicPath); console.log(`Subscribed to topic: ${topicPath}`); // Example: Publish a JSON value (requires appropriate permissions on the Diffusion server) const topicControl = session.topicUpdate.createUpdateContext(); await topicControl.set( topicPath, diffusion.datatypes.json(), diffusion.datatypes.json().newValue({ message: 'Hello, Diffusion!', timestamp: Date.now() }) ); console.log('Published a message to the topic.'); // Keep the session open for a bit to receive updates await new Promise(resolve => setTimeout(resolve, 10000)); } catch (error: any) { console.error('Diffusion connection or operation failed:', error.message || error); } finally { if (session) { await session.close(); console.log('Diffusion session closed.'); } } } runDiffusionClient();