@memberjunction/data-context-server

Server-side implementation of the MemberJunction Data Context system. Loads the data of sql-type DataContextItem objects by running their SQL through a query provider's screened ad-hoc path.

Overview

The @memberjunction/data-context-server package extends the base DataContextItem class from @memberjunction/data-context with a server-side implementation of LoadFromSQL. It runs the item's SQL through RunQuery({ SQL }) on a query provider, the same ad-hoc path ExecuteAdhocQuery uses, so the SQL must be a single read statement. On PostgreSQL that path also runs it in a read-only transaction that is rolled back. It never sends SQL to a raw connection pool. This is the server counterpart to the client-side GraphQL-based data context loading.

graph TD
    A["DataContextItemServer"] -->|extends| B["DataContextItem
(data-context package)"]
    A -->|"RunQuery({ SQL })"| C["Read-only query provider"]
    C --> D["Database"]

    E["Server-Side Code
(MJAPI, Actions, etc.)"] --> A
    F["Client-Side Code
(Angular, React)"] --> G["DataContextItemClient
(GraphQL-based)"]

    style A fill:#2d6a9f,stroke:#1a4971,color:#fff
    style B fill:#7c5295,stroke:#563a6b,color:#fff
    style C fill:#2d8659,stroke:#1a5c3a,color:#fff
    style D fill:#2d8659,stroke:#1a5c3a,color:#fff
    style E fill:#b8762f,stroke:#8a5722,color:#fff
    style G fill:#b8762f,stroke:#8a5722,color:#fff
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Installation

npm install @memberjunction/data-context-server
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How It Works

The package registers DataContextItemServer as a subclass of DataContextItem using MemberJunction's @RegisterClass decorator. When server-side code creates a DataContextItem, the class factory automatically returns the server implementation.

import '@memberjunction/data-context-server';
// DataContextItem instances can now load `sql` items on the server
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The LoadFromSQL method:

1. Receives a query provider (IRunQueryProvider) as the data source. MJServer passes its read-only provider.
2. Refuses when there is no context user, or when the data source is not a query provider (for example a raw connection pool)
3. Runs DataContextItem.SQL through RunQuery({ SQL }) for the context user. The provider accepts only a single read statement.
4. Stores the result rows in DataContextItem.Data
5. Returns success/failure with error details on DataLoadingError

Callers decide who may run an item's SQL. MJServer's GetDataContextData and GetDataContextItemData queries allow it only for the data context's owner or an administrator, never for a scope-limited session, and only on the read-only provider.

Dependencies

License

ISC