ObjectMapper.ts

/**
 * @packageDocumentation
 * @module Databind
 */

import {
  JsonStringifier
} from '../core/JsonStringifier';
import {
  JsonParser
} from '../core/JsonParser';
import {
  JsonParserContext,
  JsonStringifierContext
} from '../@types';

/**
 * ObjectMapper provides functionality for reading and writing JSON.
 * It is also highly customizable to work both with different styles of JSON content,
 * and to support more advanced Object concepts such as polymorphism and Object identity.
 *
 * ObjectMapper will use instances of {@link JsonParser} and {@link JsonStringifier}
 * for implementing actual reading/writing of JSON.
 */
export class ObjectMapper {
  /**
   * Default context to use during serialization.
   */
  defaultStringifierContext: JsonStringifierContext;
  /**
   * Default context to use during deserialization.
   */
  defaultParserContext: JsonParserContext;

  /**
   *
   * @param defaultStringifierContext - Default context to use during serialization.
   * @param defaultParserContext - Default context to use during deserialization.
   */
  constructor(
    defaultStringifierContext: JsonStringifierContext = JsonStringifier.makeDefaultContext(),
    defaultParserContext: JsonParserContext = JsonParser.makeDefaultContext()) {
    this.defaultStringifierContext = defaultStringifierContext;
    this.defaultParserContext = defaultParserContext;
  }

  /**
   * Method for serializing a JavaScript object or a value to a JSON string.
   * Context will be merged using {@link JsonStringifier.mergeContexts} with {@link defaultStringifierContext}.
   *
   * @param obj - the JavaScript object or value to be serialized.
   * @param context - the context to be used during serialization.
   */
  stringify<T>(obj: T, context?: JsonStringifierContext): string {
    context = JsonStringifier.mergeContexts([this.defaultStringifierContext, context]);

    const jsonStringifier = new JsonStringifier<T>();
    return jsonStringifier.stringify(obj, context);
  }

  /**
   * Method for deserializing a JSON string into a JavaScript object or value.
   * Context will be merged using {@link JsonParser.mergeContexts} with {@link defaultParserContext}.
   *
   * @param text - the JSON string to be deserialized.
   * @param context - the context to be used during deserialization.
   */
  parse<T>(text: string, context?: JsonParserContext): T {
    context = JsonParser.mergeContexts([this.defaultParserContext, context]);

    const jsonParser = new JsonParser<T>();
    return jsonParser.parse(text, context);
  }
}