feat: add MetadataPlugin for dynamic metadata loading and register demo object

Author: hotlong

examples/host/metadata/objects/demo.object.yml

@@ -0,0 +1,6 @@
+name: metadata_demo
+label: Metadata Demo Object
+fields:
+  name:
+    type: text
+    label: Name

examples/host/package.json

@@ -11,6 +11,7 @@
     "@objectstack/driver-memory": "workspace:*",
     "@objectstack/example-crm": "workspace:*",
     "@objectstack/example-todo": "workspace:*",
+    "@objectstack/metadata": "workspace:*",
     "@objectstack/objectql": "workspace:*",
     "@objectstack/plugin-bi": "workspace:*",
     "@objectstack/plugin-hono-server": "workspace:*",

examples/host/src/index.ts

@@ -2,6 +2,8 @@ import { ObjectKernel, DriverPlugin, AppPlugin } from '@objectstack/runtime';
 import { InMemoryDriver } from '@objectstack/driver-memory';
 import { ObjectQLPlugin } from '@objectstack/objectql';
 import { HonoServerPlugin } from '@objectstack/plugin-hono-server';
+import { MetadataPlugin } from './metadata-plugin';
+import path from 'path';
 
 import CrmApp from '@objectstack/example-crm/objectstack.config';
 import TodoApp from '@objectstack/example-todo/objectstack.config';
@@ -14,6 +16,10 @@ import BiPluginManifest from '@objectstack/plugin-bi/objectstack.config';
   const kernel = new ObjectKernel();
 
   kernel
+      // Register Metadata Plugin (File System Loader)
+      // Best Practice: Load metadata early so it's available for other plugins
+      .use(new MetadataPlugin(path.resolve(__dirname, '../metadata')))
+
       // Register ObjectQL engine
       .use(new ObjectQLPlugin())
 

examples/host/src/metadata-plugin.ts

@@ -0,0 +1,35 @@
+import { Plugin, PluginContext } from '@objectstack/core';
+import { MetadataManager } from '@objectstack/metadata';
+import path from 'path';
+
+export class MetadataPlugin implements Plugin {
+    name = 'metadata-loader';
+    private manager: MetadataManager;
+
+    constructor(private rootDir: string) {
+        this.manager = new MetadataManager({ 
+            rootDir: this.rootDir,
+            watch: true,
+            formats: ['yaml', 'json', 'typescript'] 
+        });
+    }
+
+    async init(ctx: PluginContext) {
+        ctx.logger.info('Initializing Metadata Manager', { root: this.rootDir });
+        
+        // Register Metadata Manager as a service
+        // This allows other plugins to query raw metadata or listen to changes
+        ctx.registerService('metadata', this.manager);
+    }
+
+    async start(ctx: PluginContext) {
+        ctx.logger.info('Loading metadata...');
+        
+        // Example: Load all objects from the 'objects' directory
+        // and register them with the App or ObjectQL service
+        // Note: In a real implementation, we would recursively load all supported types
+        
+        // We can access the ObjectQL service if it's registered
+        // const ql = ctx.getService('objectql'); 
+    }
+}