Remove an Object from Array which is nested in an Object

Question

I started a little bit playing with redux and i am amazed so far. My problem right now is, that my new reducer function changes the type of one state variable and i dont want that.

The state shall have a form like that:

I only want to delete an object from a jsons array:

pseudo:
delete state.items[item_index].jsons[json_to_delete_index]

I ended up with this reducer, which is returning the item state now as an object and not as an array.

case DELETE_JSON:
    const item_index = state.items.findIndex((url) => url.url_id === action.payload.url_id);
    const json_index = state.items[item_index].jsons.findIndex((json) => json.json_id === action.payload.json_id);
    return {
        ...state,
        items: {
            ...state.items,
            [item_index]: {
                ...state.items[item_index],
                jsons:
                    [
                        ...state.items[item_index].jsons.splice(0, json_index),
                        ...state.items[item_index].jsons.splice(json_index + 1)
                    ]
            }
        }
    };

I tried various approaches so far, but changing states inside highly nested objects seems still like a torture with redux. Does anybody maybe know a way to write it?

Mahdi N · Accepted Answer · 2020-04-19 23:33:52Z

1

Changing state with highly nested objects can be difficult but map and filter functions are really helpful in this case

const item_index = state.items.findIndex((url) => url.url_id === action.payload.url_id);
const json_index = state.items[item_index].jsons.findIndex((json) => json.json_id === action.payload.json_id);

return { 
   ...state, 
   items: state.items.map((item, index) => (index === item_index ? 
   { ...item, item.jsons.filter((json, i) => (i !== json_index)) } : item)) 
   };

edited Apr 19, 2020 at 23:33

answered Apr 19, 2020 at 23:27

Mahdi N

2,1783 gold badges19 silver badges41 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

jo87casi · Accepted Answer · 2020-04-19 23:36:59Z

0

I solved it by using update() from immutability-helpers. Very handy

import update from 'immutability-helper';

/* some other code */

case DELETE_JSON:
    const item_index = state.items.findIndex((url) => url.url_id === action.payload.url_id);
    const json_index = state.items[item_index].jsons.findIndex((json) => json.json_id === action.payload.json_id);
    return update(state, {
            items: {
                [item_index]: {
                    jsons: {$splice: [[json_index]]}
                }
            }
        });

answered Apr 19, 2020 at 23:36

jo87casi

4606 silver badges18 bronze badges

Collectives™ on Stack Overflow

Remove an Object from Array which is nested in an Object

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related