#DataSourceManager

NocoBase provides DataSourceManager for managing multiple data sources. Each DataSource has its own Database, ResourceManager, and ACL instances, allowing you to flexibly manage and extend different data sources.

#Basic Concepts

Each DataSource instance contains the following:

• dataSource.collectionManager: Used to manage collections and fields.
• dataSource.resourceManager: Handles resource-related operations (such as CRUD, etc.).
• dataSource.acl: Access control (ACL) for resource operations.

For convenient access, NocoBase provides aliases for main data source members:

• app.db is equivalent to dataSourceManager.get('main').collectionManager.db
• app.acl is equivalent to dataSourceManager.get('main').acl
• app.resourceManager is equivalent to dataSourceManager.get('main').resourceManager

#Common Methods

#dataSourceManager.get(dataSourceKey)

Returns the specified DataSource instance.

const dataSource = dataSourceManager.get('main');

#dataSourceManager.use()

Register middleware for all data sources, which will affect operations on all data sources.

dataSourceManager.use(async (ctx, next) => {
  console.log('This middleware applies to all data sources');
  await next();
});

#dataSourceManager.beforeAddDataSource()

Executes before data source loading. Typically used for static class registration, such as model classes and field type registration:

dataSourceManager.beforeAddDataSource((dataSource: DataSource) => {
  const collectionManager = dataSource.collectionManager;
  if (collectionManager instanceof SequelizeCollectionManager) {
    collectionManager.registerFieldTypes({
      belongsToArray: BelongsToArrayField, // Register custom field type
    });
  }
});

#dataSourceManager.afterAddDataSource()

Executes after data source loading. Typically used for registering operations, setting access control, etc.

dataSourceManager.afterAddDataSource((dataSource) => {
  dataSource.resourceManager.registerActionHandler('downloadXlsxTemplate', downloadXlsxTemplate);
  dataSource.resourceManager.registerActionHandler('importXlsx', importXlsx);
  dataSource.acl.allow('*', 'downloadXlsxTemplate', 'loggedIn'); // Logged-in users can access
});

#Data Source Extension

For complete data source extension, please refer to the data source extension chapter.

#Related Links

• Database - CRUD, Repository, transactions, and database events
• Collections - Define or extend data table structures with code
• ResourceManager - Register custom APIs and resource operations
• ACL - Role permissions, permission snippets, and access control
• Plugin - Plugin class lifecycle, member methods, and the app object