apg-js-examples/src/execute-rule/main.js

Examples of using the suite of apg-js applications and libraries.

/*  *************************************************************************************
 *   copyright: Copyright (c) 2021 Lowell D. Thomas, all rights reserved
 *     license: BSD-2-Clause (https://opensource.org/licenses/BSD-2-Clause)
 *   ********************************************************************************* */
module.exports = function main(args) {
  /* display the program arguments */
  console.log('execute-rule args');
  console.dir(args);

  /* the help screen */
  let desc = '';
  desc += 'The "execute-rule" example is a demonstration of how to call a UDT or rule name\n';
  desc += 'from a call back function.\n';
  desc +=
    'Examine or run a debugger on this module, "apg-js-examples/src/execute-rule/main.js" to study the example.\n';
  let help = '';
  help += 'Usage: npm run execute-rule [-- arg]\n';
  help += '  arg: help (or no arg) to display this help screen.\n';
  help += '       rule demonstrates executing a rule (RNM operator) from a UDT call back function\n';
  help += '       udt  demonstrates executing a UDT operator from a rule callback function\n';
  help += '       all  all demonstrations\n';
  if (!args[0]) {
    /* display the help screen and exit */
    console.log(desc);
    console.log(help);
    return;
  }
  if (args[0] === 'help') {
    console.log(help);
    return;
  }
  console.log();
  console.log('Demonstrate calling a rule or UDT from a call back function.');
  console.log();

  switch (args[0]) {
    case 'rule':
      require('./more-app');
      break;
    case 'udt':
      require('./colors-app');
      break;
    case 'all':
      require('./more-app');
      require('./colors-app');
      break;
    default:
      console.log(`unrecognized argument: ${args[0]}`);
      console.log(help);
  }
};