track.js

import LogmaticJs from 'logmatic-js';

const track = function (verb) {

  // Event fields
  const _verb = verb;
  let _object = null;
  let _target = null;
  let _start = null;

  // The builder
  const t = {};

  // Start timing the event
  t.timed = () => {
    _start = new Date();
    return t;
  };

  // Define object
  t.of = (type, id, content) => {
    if (type != null) {
      _object = { objectType: type };
      if (id != null) {
        _object.id = id;
      }
      if (content != null) {
        _object.content = content;
      }
    }
    return t;
  };

  // Define target
  t.on = (type, id, content) => {
    if (type != null) {
      _target = { objectType: type };
      if (id != null) {
        _target.id = id;
      }
      if (content != null) {
        _target.content = content;
      }
    }
    return t;
  };

  // Emit the event
  t.emit = () => {
    const msg = [ _verb ];
    const payload = {
      verb: _verb
    };
    if (_object != null) {
      msg.push(_object.objectType);
      if (_object.content || _object.id) {
        msg.push(JSON.stringify(_object.content || _object.id));
      }
      payload.object = _object;
    }
    if (_target != null) {
      msg.push('on', _target.objectType);
      if (_target.content || _target.id) {
        msg.push(JSON.stringify(_target.content || _target.id));
      }
      payload.target = _target;
    }
    if (_start != null) {
      const duration = new Date().getTime() - _start.getTime();
      msg.push('took', duration, 'ms');
      payload.took = duration;
    }

    logmaticJs.log(msg.join(' '), payload);
  };

  return t;
};

export default track;