ObjectSource

The ObjectSource implementation of ConfigurationSource is quite straightforward; it simply uses a JavaScript Object as a source of configuration data. This is most useful for setting application defaults or runtime overrides.

The default Configurator source list uses two ObjectSource implementations:

• A low-priority source reading from context.defaults (sequence 300) - for application defaults
• A high-priority source reading from context.overrides (sequence 1000) - for runtime overrides

You can create additional ObjectSource instances with custom contextName values to read from different fields in the context.

import { ObjectSource } from '@versionzero/configurator/sources';

// Custom source reading from context.magic
const magicSource = new ObjectSource({ contextName: 'magic', sequence: 500 });

const config = await Configurator.load(schema, {
  sources: [
    ...Configurator.getDefaultSources(),
    magicSource
  ],
  magic: { server: { hostname: 'localhost' } }
});

caution

This library uses the word defaults in multiple contexts:

• Schema defaults (loaded by SchemaDefaultsSource) - default values defined in schema
• Application defaults (loaded by ObjectSource from context.defaults) - application-level defaults

Constructor

new ObjectSource(options)

Param	Type	Description
[options]	object	Optional settings
[options.sequence]	number	Priority number. Defaults to ConfigurationSource.DefaultSequence.APP_DEFAULTS (300)
[options.contextName]	string	Name of context field to load from (default: "data")

Examples

Basic Usage

import { ObjectSource } from '@versionzero/configurator/sources';

// Default contextName is 'data'
const source = new ObjectSource();

// Custom contextName
const defaultsSource = new ObjectSource({ contextName: 'defaults', sequence: 300 });
const overridesSource = new ObjectSource({ contextName: 'overrides', sequence: 1000 });

Complete Example

import { Schema, Configurator } from '@versionzero/configurator';

const schema = new Schema('object')
  .property('host', new Schema('string'))
  .property('port', new Schema('number'));

// Using the built-in defaults and overrides
const config = await Configurator.load(schema, {
  defaults: { host: 'localhost', port: 3000 },  // Low priority (300)
  overrides: { port: 8080 }                     // High priority (1000)
});

console.log(config); // { host: 'localhost', port: 8080 }