Ticruz
140 lines
3.0 KiB
Markdown
140 lines
3.0 KiB
Markdown
# Application Context
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The `@welshman/app` package uses a global context system to configure core behaviors.
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Understanding the app context is essential as it powers [session/authentication](/app/session), [relay routing](/app/relay) and [request handling](/app/request).
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## Basic Setup
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```typescript
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import {ctx, setContext} from '@welshman/lib'
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import {getDefaultNetContext, getDefaultAppContext} from '@welshman/app'
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// Initialize app with default settings
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setContext({
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net: getDefaultNetContext(),
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app: getDefaultAppContext()
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})
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// Access context anywhere
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console.log(ctx.app.router)
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console.log(ctx.net.pool)
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```
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## Default App Context
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```typescript
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export type AppContext = {
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// Smart relay routing system
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router: Router
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// Time to wait between batched requests (ms)
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requestDelay: number // default: 50
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// Time to wait for NIP-42 relay auth (ms)
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authTimeout: number // default: 300
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// Time to wait for request completion (ms)
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requestTimeout: number // default: 3000
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// URL of metadata service (optional)
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dufflepudUrl?: string
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// Additional relays for indexed content
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indexerRelays?: string[]
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}
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// Example with custom settings
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setContext({
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app: getDefaultAppContext({
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requestDelay: 100,
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authTimeout: 500,
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requestTimeout: 5000,
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dufflepudUrl: "https://api.example.com",
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indexerRelays: [
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"wss://relay.example.com",
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"wss://indexed.example.com"
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]
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})
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})
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```
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## Network Context
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```typescript
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export type NetContext = {
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// Global connection pool
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pool: Pool
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// How to handle NIP-42 auth
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authMode: AuthMode // default: 'implicit'
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// Event validation and handling
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onEvent: (url: string, event: TrustedEvent) => void
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isDeleted: (url: string, event: TrustedEvent) => boolean
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isValid: (url: string, event: TrustedEvent) => boolean
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// Event signing (used by all packages)
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signEvent: (event: StampedEvent) => Promise<SignedEvent>
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// Subscription optimization
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optimizeSubscriptions: (subs: Subscription[]) => RelaysAndFilters[]
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}
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// Example with custom validation
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setContext({
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net: getDefaultNetContext({
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// Custom event validation
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isValid: (url, event) => {
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if (url === LOCAL_RELAY_URL) return true
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return hasValidSignature(event)
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},
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// Track deleted events
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isDeleted: (url, event) =>
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repository.isDeleted(event),
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// Custom event handling
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onEvent: (url, event) => {
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// Save to local repository
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repository.publish(event)
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// Track which relay it came from
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tracker.track(event.id, url)
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}
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})
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})
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```
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## Using Context Values
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Once configured, context values are used throughout the app:
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```typescript
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import {ctx} from '@welshman/lib'
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// Smart relay routing
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const relays = ctx.app.router
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.ForPubkey(pubkey)
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.getUrls()
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// Publish with timeout
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const pub = publish({
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event,
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relays,
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timeout: ctx.app.requestTimeout
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})
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// Subscribe with auth
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const sub = subscribe({
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filters,
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relays,
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authTimeout: ctx.app.authTimeout
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})
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// Check connection pool
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const connected = ctx.net.pool
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.get(relay)
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.socket.status === 'open'
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```
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