ImmutableJS: Upating an object inside an array of arrays

Question

I have a somewhat complex state as follows:

array:
  array:
    object,
    object,
    etc...
  array:
  etc...

Simply put, an array containing a number of arrays that hold objects. I am trying to find one of these objects inside this mess according to its Id and update it (namely setting a completed value to true), but haven't been able to so far. Using Mudash, I managed to find this object, but I have no idea how to pass it up again to return it, my code is as follows:

  return state.update('data', (arr) => {
    _.forEach(arr, function(item) {
      _.forEach(item, function(elt) {
        if(elt.Id == action.Id) {
          console.log('Item Found');
          elt.set('completed', true);
        }

      });
    });
    return arr;
  });

Is there some simple way to accomplish this? Thank you.

score 1 · Answer 1 · edited May 23 '17 at 11:53

1

If you are asking how to mutate a part of an immutable object then there will be no answer that is going to satisfy you. See this answer for much more details:

Immutable.js relationships

edited May 23 '17 at 11:53

Community

1
1

answered Feb 13 '17 at 13:31

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score 1 · Accepted Answer · answered Jun 22 '17 at 05:10

The key here is that you cannot mutate values in place. Instead, you have you approach the problem from thinking about how you change every parent value in the deeply nested data structure.

A simple use of the _.map method will do the trick...

const _ = require('mudash')

return _.update(state, 'data', (arr) => {
  return _.map(arr, function(item) {
    return _.map(item, function(elt) {
      if(_.get(elt, 'Id') == action.Id) {
        console.log('Item Found');
        return _.set(elt, 'completed', true);
      }
      return elt;
    });
  });
});

This is an elegant solution. Thank you :) – Unforgiven Jun 22 '17 at 07:55 — Unforgiven, Jun 22 '17 at 07:55

ImmutableJS: Upating an object inside an array of arrays

2 Answers2