dpaw-qweb-app/src/model.js

Simple viewer app to interface with QGIS/monorail

/**
 * @fileOverview
 * @name model.js
 * @author Gavin Coombes
 * @license BSD-3-Clause
 */

let Rx = require('rx');
let u = require('dpaw-brocket-utility');
let log = u.log;

function calculateBMI(weight, height) {
  let heightMeters = height * 0.01;
  return Math.round(weight / (heightMeters * heightMeters));
}

// NEW!

// UPDATED!
function model(actions, incoming$) {

  let bmi$ = Rx.Observable.combineLatest(
    actions.changeWeight$.startWith(70), actions.changeHeight$.startWith(170),
    (weight, height) => ({weight, height, bmi: calculateBMI(weight, height)})
  );

  let messageArr$ = incoming$
        .do(v => log('prescan got val ', v))
        // .map(v => JSON.parse(v))
        .startWith([{tag: 'init', payload: 'in the beginning'}])
        .pluck('payload')
        .scan(myAggregate, []);

  let state$ = Rx.Observable.combineLatest(
    messageArr$, bmi$,
    (messageArr, bmi) => ({messageArr, bmi})
  );
  return state$;
}

module.exports = model;

function myAggregate(acc, val, ix, src) {
  acc.push(val);
  return acc.slice(-10);
}