lowdb-nativescript-adapter/index.js

A lowdb adapter for using the database from NativeScript apps.

const AdapterBase = require('lowdb/adapters/Base');
const fs = require('file-system');


class NativeScriptAdapter extends AdapterBase {
  read() {
    const dbFilePath = this.syncFilePath();

    if (fs.File.exists(dbFilePath)) {
      try {
        const dbFile = fs.File.fromPath(dbFilePath);
        const data = dbFile.readTextSync();
        return data ? this.deserialize(data) : this.defaultValue;
      } catch (e) {
        if (e instanceof SyntaxError) {
          e.message = `Malformed JSON in file: ${this.source}\n${e.message}`
        }
        throw e
      }
    } else {
      this.write(this.defaultValue);
      return this.defaultValue
    }
  }

  write(data) {
    const dbFile = fs.File.fromPath(this.syncFilePath());
    dbFile.writeTextSync(this.serialize(data));
  }

  syncFilePath() {
    const documents = fs.knownFolders.documents();
    return fs.path.join(documents.path, this.source);
  }
}

module.exports = NativeScriptAdapter;