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| 1 | +# @objectstack/metadata |
| 2 | + |
| 3 | +Metadata loading, saving, and persistence for ObjectStack. |
| 4 | + |
| 5 | +## Overview |
| 6 | + |
| 7 | +The `@objectstack/metadata` package provides a unified interface for managing metadata across the ObjectStack ecosystem. It handles: |
| 8 | + |
| 9 | +- **Metadata Serialization/Deserialization** - Support for JSON, YAML, TypeScript, and JavaScript formats |
| 10 | +- **File System Operations** - Load, save, and watch metadata files |
| 11 | +- **Validation** - Integration with Zod schemas from `@objectstack/spec` |
| 12 | +- **Caching** - ETag-based caching for performance optimization |
| 13 | +- **File Watching** - Development mode with automatic reload on file changes |
| 14 | + |
| 15 | +## Installation |
| 16 | + |
| 17 | +```bash |
| 18 | +pnpm add @objectstack/metadata |
| 19 | +``` |
| 20 | + |
| 21 | +## Quick Start |
| 22 | + |
| 23 | +```typescript |
| 24 | +import { MetadataManager } from '@objectstack/metadata'; |
| 25 | +import type { ServiceObject } from '@objectstack/spec/data'; |
| 26 | + |
| 27 | +// Create manager |
| 28 | +const manager = new MetadataManager({ |
| 29 | + rootDir: './metadata', |
| 30 | + formats: ['typescript', 'json', 'yaml'], |
| 31 | + cache: { enabled: true, ttl: 3600 }, |
| 32 | + watch: process.env.NODE_ENV === 'development', |
| 33 | +}); |
| 34 | + |
| 35 | +// Load metadata |
| 36 | +const customer = await manager.load<ServiceObject>('object', 'customer'); |
| 37 | + |
| 38 | +// Save metadata |
| 39 | +await manager.save('object', 'project', projectObject, { |
| 40 | + format: 'typescript', |
| 41 | + prettify: true, |
| 42 | +}); |
| 43 | + |
| 44 | +// Load multiple items |
| 45 | +const objects = await manager.loadMany<ServiceObject>('object', { |
| 46 | + patterns: ['**/*.object.ts', '**/*.object.json'], |
| 47 | +}); |
| 48 | + |
| 49 | +// Watch for changes |
| 50 | +manager.watch('object', (event) => { |
| 51 | + console.log(`Object ${event.type}:`, event.name); |
| 52 | +}); |
| 53 | +``` |
| 54 | + |
| 55 | +## API |
| 56 | + |
| 57 | +### MetadataManager |
| 58 | + |
| 59 | +Main class for metadata operations. |
| 60 | + |
| 61 | +#### Constructor |
| 62 | + |
| 63 | +```typescript |
| 64 | +new MetadataManager(config: MetadataManagerConfig) |
| 65 | +``` |
| 66 | + |
| 67 | +**Config options:** |
| 68 | +- `rootDir` - Root directory for metadata files |
| 69 | +- `formats` - Enabled serialization formats (default: `['typescript', 'json', 'yaml']`) |
| 70 | +- `cache` - Cache configuration with `enabled` and `ttl` options |
| 71 | +- `watch` - Enable file watching (default: `false`) |
| 72 | +- `watchOptions` - File watcher options (`ignored`, `persistent`, `ignoreInitial`) |
| 73 | + |
| 74 | +#### Methods |
| 75 | + |
| 76 | +**load<T>(type: string, name: string, options?: MetadataLoadOptions): Promise<T | null>** |
| 77 | + |
| 78 | +Load a single metadata item. |
| 79 | + |
| 80 | +```typescript |
| 81 | +const customer = await manager.load<ServiceObject>('object', 'customer'); |
| 82 | +``` |
| 83 | + |
| 84 | +**loadMany<T>(type: string, options?: MetadataLoadOptions): Promise<T[]>** |
| 85 | + |
| 86 | +Load multiple metadata items matching patterns. |
| 87 | + |
| 88 | +```typescript |
| 89 | +const objects = await manager.loadMany<ServiceObject>('object', { |
| 90 | + patterns: ['**/*.object.ts'], |
| 91 | + limit: 100, |
| 92 | +}); |
| 93 | +``` |
| 94 | + |
| 95 | +**save<T>(type: string, name: string, data: T, options?: MetadataSaveOptions): Promise<MetadataSaveResult>** |
| 96 | + |
| 97 | +Save metadata to disk. |
| 98 | + |
| 99 | +```typescript |
| 100 | +await manager.save('object', 'customer', customerObject, { |
| 101 | + format: 'typescript', |
| 102 | + prettify: true, |
| 103 | + backup: true, |
| 104 | +}); |
| 105 | +``` |
| 106 | + |
| 107 | +**exists(type: string, name: string): Promise<boolean>** |
| 108 | + |
| 109 | +Check if metadata item exists. |
| 110 | + |
| 111 | +```typescript |
| 112 | +const exists = await manager.exists('object', 'customer'); |
| 113 | +``` |
| 114 | + |
| 115 | +**list(type: string): Promise<string[]>** |
| 116 | + |
| 117 | +List all items of a type. |
| 118 | + |
| 119 | +```typescript |
| 120 | +const objectNames = await manager.list('object'); |
| 121 | +``` |
| 122 | + |
| 123 | +**watch(type: string, callback: WatchCallback): void** |
| 124 | + |
| 125 | +Watch for metadata changes. |
| 126 | + |
| 127 | +```typescript |
| 128 | +manager.watch('object', (event) => { |
| 129 | + if (event.type === 'added') { |
| 130 | + console.log('New object:', event.name); |
| 131 | + } |
| 132 | +}); |
| 133 | +``` |
| 134 | + |
| 135 | +**stopWatching(): Promise<void>** |
| 136 | + |
| 137 | +Stop all file watching. |
| 138 | + |
| 139 | +## Serialization Formats |
| 140 | + |
| 141 | +### JSON |
| 142 | + |
| 143 | +```json |
| 144 | +{ |
| 145 | + "name": "customer", |
| 146 | + "label": "Customer", |
| 147 | + "fields": { |
| 148 | + "name": { "type": "text", "label": "Name" } |
| 149 | + } |
| 150 | +} |
| 151 | +``` |
| 152 | + |
| 153 | +### YAML |
| 154 | + |
| 155 | +```yaml |
| 156 | +name: customer |
| 157 | +label: Customer |
| 158 | +fields: |
| 159 | + name: |
| 160 | + type: text |
| 161 | + label: Name |
| 162 | +``` |
| 163 | +
|
| 164 | +### TypeScript |
| 165 | +
|
| 166 | +```typescript |
| 167 | +import type { ServiceObject } from '@objectstack/spec/data'; |
| 168 | + |
| 169 | +export const metadata: ServiceObject = { |
| 170 | + name: 'customer', |
| 171 | + label: 'Customer', |
| 172 | + fields: { |
| 173 | + name: { type: 'text', label: 'Name' }, |
| 174 | + }, |
| 175 | +}; |
| 176 | + |
| 177 | +export default metadata; |
| 178 | +``` |
| 179 | + |
| 180 | +## Architecture |
| 181 | + |
| 182 | +The metadata package is designed as a Layer 3 package in the ObjectStack architecture: |
| 183 | + |
| 184 | +``` |
| 185 | +@objectstack/metadata (Layer 3) |
| 186 | +├── Dependencies: |
| 187 | +│ ├── @objectstack/spec (validation) |
| 188 | +│ ├── @objectstack/core (logging, DI) |
| 189 | +│ ├── @objectstack/types (shared types) |
| 190 | +│ ├── glob (file pattern matching) |
| 191 | +│ ├── js-yaml (YAML support) |
| 192 | +│ └── chokidar (file watching) |
| 193 | +└── Used By: |
| 194 | + ├── @objectstack/cli (code generation) |
| 195 | + ├── @objectstack/runtime (manifest loading) |
| 196 | + └── @objectstack/objectql (registry persistence) |
| 197 | +``` |
| 198 | + |
| 199 | +## License |
| 200 | + |
| 201 | +MIT |
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