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useKanelContext ​

useKanelContext() is the V4 way to access Kanel's runtime context (configuration, schemas, etc.) from within hooks and custom functions.

Overview ​

In V4, hooks no longer receive configuration as a parameter. Instead, you use useKanelContext() to access the context when needed:

V3 (deprecated):

javascript
module.exports = {
  preRenderHooks: [
    (outputAcc, instantiatedConfig) => {
      console.log(instantiatedConfig.outputPath);
      return outputAcc;
    },
  ],
};

V4:

javascript
import { useKanelContext } from "kanel";

module.exports = {
  preRenderHooks: [
    (outputAcc) => {
      const context = useKanelContext();
      console.log(context.config.outputPath);
      return outputAcc;
    },
  ],
};

The KanelContext Type ​

useKanelContext() returns a KanelContext object with the following structure:

typescript
type KanelContext = {
  /** General TypeScript configuration affecting all TypeScript generators */
  typescriptConfig: TypescriptConfig;

  /** Original config as passed to Kanel */
  config: Config;

  /** Extracted database schemas */
  schemas: Record<string, Schema>;
};

typescriptConfig ​

Contains TypeScript-specific settings that apply to all TypeScript generators:

javascript
const context = useKanelContext();

console.log(context.typescriptConfig.enumStyle); // 'literal-union' or 'enum'
console.log(context.typescriptConfig.tsModuleFormat); // 'esm', 'commonjs', etc.

config ​

The original configuration object as passed to Kanel. This is either a V3 or V4 config:

javascript
const context = useKanelContext();

console.log(context.config.connection); // Database connection config
console.log(context.config.outputPath); // Output directory
console.log(context.config.preDeleteOutputFolder); // Boolean
console.log(context.config.generators); // Array of generator functions (V4)

schemas ​

The extracted database schemas as a record keyed by schema name:

javascript
const context = useKanelContext();

const publicSchema = context.schemas.public;

// Iterate over all tables in the public schema
for (const table of publicSchema.tables) {
  console.log(table.name);
  console.log(table.columns);
}

// Access views, enums, etc.
console.log(publicSchema.views);
console.log(publicSchema.types);

The Schema type comes from extract-pg-schema and contains:

  • tables - Table definitions
  • views - View definitions
  • materializedViews - Materialized view definitions
  • types - Composite types, enums, domains, ranges

How It Works ​

useKanelContext() uses Node.js's AsyncLocalStorage to provide context that's automatically available throughout the async execution chain.

See Also ​