Manipulate JSON and Group keys in JavaScript

Question

I'm trying to get a certain structure for my JSON but I'm struggling in the process and get an infinite loop.

I managed to get to a certain point with the original file by using the reduce() method, but I'm stuck with the last step.

here is the JSON:

{
    "someNumbers_like_15269": {
        "someNumbers_like_35896": [{
            "TestPoint": "A",
            "ItemNo": "12110",
            "TestDesc": "Penalty Points"
        }, {
            "TestPoint": "A",
            "ItemNo": "12110",
            "TestDesc": "Brix"
        }, {
            "TestPoint": "B",
            "ItemNo": "12110",
            "TestDesc": "Texture"
        }, {
            "TestPoint": "B",
            "ItemNo": "12110",
            "TestDesc": "Viscosity"
        }, {
            "TestPoint": "C",
            "ItemNo": "12110",
            "TestDesc": "PH"
        }, {
            "TestPoint": "C",
            "ItemNo": "12110",
            "TestDesc": "Taste"
        }]
    }
}

And the desired result

{
"someNumbers_like_15269": {
    "someNumbers_like_35896": {
        "ItemNo": "12110",
        "someOtherThing": "blabla",
        "Test": [{
            "TestPoint": "A",
            "TestDesc": ["Penalty Points", "Brix"]
        }, {
            "TestPoint": "B",
            "TestDesc": ["Texture", "Viscosity"]
        }, {
            "TestPoint": "C",
            "TestDesc": ["PH", "Taste"]
        }]
    }
}

} PS: There will be multiple CC and multiple Batches, the JSON as more than 85 thousand lines

**

my original attempt can be found in here

**

why do people downvote without any comment?

Jonathan
– Jonathan

2018-06-08 09:06:46 +00:00
Commented Jun 8, 2018 at 9:06 — Jonathan
– Jonathan, Commented Jun 8, 2018 at 9:06

Nikhil Aggarwal · Accepted Answer · 2018-06-08 10:26:35Z

3

Use Array.reduce, Array.forEach, Object.values and Object.entries

var data = {"someNumbers_like_15269":{"someNumbers_like_35896":[{"TestPoint":"A","ItemNo":"12110","TestDesc":"Penalty Points"},{"TestPoint":"A","ItemNo":"12110","TestDesc":"Brix"},{"TestPoint":"B","ItemNo":"12110","TestDesc":"Texture"},{"TestPoint":"B","ItemNo":"12110","TestDesc":"Viscosity"},{"TestPoint":"C","ItemNo":"12110","TestDesc":"PH"},{"TestPoint":"C","ItemNo":"12110","TestDesc":"Taste"}],"someNumbers_like_21":[{"TestPoint":"A","ItemNo":"12110","TestDesc":"Penalty Points"},{"TestPoint":"A","ItemNo":"12110","TestDesc":"Brix"},{"TestPoint":"B","ItemNo":"12110","TestDesc":"Texture"},{"TestPoint":"B","ItemNo":"12110","TestDesc":"Viscosity"},{"TestPoint":"C","ItemNo":"12110","TestDesc":"PH"},{"TestPoint":"C","ItemNo":"12110","TestDesc":"Taste"}]},"someNumbers_like_15270":{"someNumbers_like_35800":[{"TestPoint":"A","ItemNo":"12110","TestDesc":"Penalty Points"},{"TestPoint":"A","ItemNo":"12110","TestDesc":"Brix"},{"TestPoint":"B","ItemNo":"12110","TestDesc":"Texture"},{"TestPoint":"B","ItemNo":"12110","TestDesc":"Viscosity"},{"TestPoint":"C","ItemNo":"12110","TestDesc":"PH"},{"TestPoint":"C","ItemNo":"12110","TestDesc":"Taste"}]}};

// Iterate for all first level values
Object.values(data).forEach(v => {
  // Iterate for all second level values
  Object.entries(v).forEach(([k,v1]) => {
    // Set the updated value back in object
    v[k] = Object.values(v1.reduce((a,{TestDesc, TestPoint, ...rest}) => {
      a[TestPoint] ? a[TestPoint].TestDesc.push(TestDesc) : a[TestPoint] = {TestPoint, ...rest, TestDesc : [TestDesc]};
      return a;
      }, {}));
  });
})

console.log(data);

EDIT

var data = {"someNumbers_like_15269":{"someNumbers_like_35896":[{"TestPoint":"A","ItemNo":"12110","TestDesc":"Penalty Points"},{"TestPoint":"A","ItemNo":"12110","TestDesc":"Brix"},{"TestPoint":"B","ItemNo":"12110","TestDesc":"Texture"},{"TestPoint":"B","ItemNo":"12110","TestDesc":"Viscosity"},{"TestPoint":"C","ItemNo":"12110","TestDesc":"PH"},{"TestPoint":"C","ItemNo":"12110","TestDesc":"Taste"}],"someNumbers_like_21":[{"TestPoint":"A","ItemNo":"12110","TestDesc":"Penalty Points"},{"TestPoint":"A","ItemNo":"12110","TestDesc":"Brix"},{"TestPoint":"B","ItemNo":"12110","TestDesc":"Texture"},{"TestPoint":"B","ItemNo":"12110","TestDesc":"Viscosity"},{"TestPoint":"C","ItemNo":"12110","TestDesc":"PH"},{"TestPoint":"C","ItemNo":"12110","TestDesc":"Taste"}]},"someNumbers_like_15270":{"someNumbers_like_35800":[{"TestPoint":"A","ItemNo":"12110","TestDesc":"Penalty Points"},{"TestPoint":"A","ItemNo":"12110","TestDesc":"Brix"},{"TestPoint":"B","ItemNo":"12110","TestDesc":"Texture"},{"TestPoint":"B","ItemNo":"12110","TestDesc":"Viscosity"},{"TestPoint":"C","ItemNo":"12110","TestDesc":"PH"},{"TestPoint":"C","ItemNo":"12110","TestDesc":"Taste"}]}};

// Iterate for all first level values
Object.values(data).forEach(v => {
  // Iterate for all second level values
  Object.entries(v).forEach(([k,v1]) => {
    let {TestDesc, TestPoint, ...rest} = v1[0];
    let Test = Object.values(v1.reduce((a,{TestDesc, TestPoint}) => {
      a[TestPoint] ? a[TestPoint].TestDesc.push(TestDesc) : a[TestPoint] = {TestPoint, TestDesc : [TestDesc]};
      return a;
    }, {}));
    v[k] = {...rest, Test};
  });
})

console.log(data);

edited Jun 8, 2018 at 10:26

answered Jun 8, 2018 at 9:07

Nikhil Aggarwal

28.5k4 gold badges46 silver badges61 bronze badges

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

6 Comments

Jonathan Over a year ago

what if I have more keys, not only TestDesc, TestPoint and ItemNo?

Jonathan Over a year ago

it's working, thanks! but I noticed some useless repetition in my desired result, can you have a look at the updated question?

Nikhil Aggarwal Over a year ago

@Jonathan - Can you provide more information on the repetition? What needs to be improved?

Jonathan Over a year ago

I moved the other keys right after the second level and moved testPoint and TestDescription into the 3rd level inside a Test object. See my desired result from the question

Nikhil Aggarwal Over a year ago

@Jonathan - What about the other properties if any? Also is ItemNo unique in an array?

|

Nina Scholz · Accepted Answer · 2018-06-08 10:43:56Z

Taking the original data and respecting any nested objects and arrays, you could take a nested approach and given key and value for grouping.

The part of Array.isArray(w) ... could be replaced by a hard coded property check, or just deleted if all keys have an array for grouping.

Outer object's keys and values, denoted by k and v, and inner keys and values of v, denoted by l and w, where all objects are destructed and rebuild with this pattern:

Object.assign(...Object
    .entries(object)
    .map(([key, value]) => ({ [key]: value })
)

in this example and for the next level, value in ({ [key]: value }) is replaced by another same structure for the nested object.

Finally a reduce takes palce and it looks for an object in the accumulator if the wanted key for grouping is found. if not it generates a new object and later it pushes the grouping vlaue to the array for collecting this item.

var data = { CC1: { Batch1: [{ TestPoint: "A", ItemNo: "12110", TestDesc: "Penalty Points" }, { TestPoint: "A", ItemNo: "12110", TestDesc: "Brix" }, { TestPoint: "B", ItemNo: "12110", TestDesc: "Texture" }, { TestPoint: "B", ItemNo: "12110", TestDesc: "Viscosity" }, { TestPoint: "C", ItemNo: "12110", TestDesc: "PH" }, { TestPoint: "C", ItemNo: "12110", TestDesc: "Taste" }] } },
    group = { key: 'TestPoint', value: 'TestDesc' },
    result = Object.assign(...Object.entries(data).map(([k, v]) => ({
        [k]: Object.assign(...Object.entries(v).map(([l, w]) => ({
            [l]: Array.isArray(w)
                ? w.reduce((r, o) => {
                    var item = r.find(p => o[group.key] === p[group.key]);
                    if (!item) {
                        r.push(item = Object.assign({}, o, { [group.value]: [] }));
                    }
                    item[group.value].push(o[group.value]);
                    return r;
                }, [])
                : w
        })))
    })));

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Finally a complete dynamic recursive approach for nested objects. If an array is found, the grouping takes place.

This code prevents duplicate entries for grouped values.

function groupBy(object, by) {
    return Array.isArray(object)
        ? object.reduce((r, o) => {
            var item = r.find(({ [by.key]: v }) => o[by.key] === v);
            if (!item) {
                item = Object.assign({}, o, { [by.value]: [] });
                r.push(item);
            }
            if (!item[by.value].includes(o[by.value])) {
                item[by.value].push(o[by.value]);
            }
            return r;
        }, [])
        : Object.assign(...Object
            .entries(object)
            .map(([key, value]) => ({ [key]: groupBy(value, by) }))
        );
}

var data = { CC1: { Batch1: [{ TestPoint: "A", ItemNo: "12110", TestDesc: "Penalty Points" }, { TestPoint: "A", ItemNo: "12110", TestDesc: "Brix" }, { TestPoint: "B", ItemNo: "12110", TestDesc: "Texture" }, { TestPoint: "B", ItemNo: "12110", TestDesc: "Viscosity" }, { TestPoint: "C", ItemNo: "12110", TestDesc: "PH" }, { TestPoint: "C", ItemNo: "12110", TestDesc: "Taste" }] } },
    result = groupBy(data, { key: 'TestPoint', value: 'TestDesc' });

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

it's working, thanks! but I noticed some useless repetition in my desired result, can you have a look at the updated question?

Collectives™ on Stack Overflow

Manipulate JSON and Group keys in JavaScript

my original attempt can be found in here

2 Answers 2

6 Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

my original attempt can be found in here

2 Answers 2

6 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related