Transform or normalize nested JSON using lodash - javascript

I am trying to transform a nested structure, using the library of lodash, I have achieved the expected result, but they are not functional if the structure changes, so I come to you to help me make more robust the function that transforms the JSON.
the initial structure looks like this
const data = {
foo: {
bar: {
baz: [{ a: 1, b: 2, c: 3 }]
},
baz: {
bar: [{ a: 1, b: 2, c: 3 }]
},
foo: {
bar: [{ a: 1, b: 2, c: 3 }]
}
},
bar: {
baz: {
bar: [{ a: 1, b: 2, c: 3 }]
}
},
baz: {
foo: {
bar: [{ a: 1, b: 2, c: 3 }]
}
}
};
after being transformed
const transform = [
{
name: 'barfoo',
results: [{ a: 1, b: 2, c: 3 }]
},
{
name: 'bazfoo',
results: [{ a: 1, b: 2, c: 3 }]
},
{
name: 'foofoo',
results: [{ a: 1, b: 2, c: 3 }]
},
{
name: 'bazbar',
results: [{ a: 1, b: 2, c: 3 }]
},
{
name: 'foobaz',
results: [{ a: 1, b: 2, c: 3 }]
}
];
The idea of the transformation is to join the nested key of the first level with the key of the parent node to generate the value of name in the new object and the value of the object in the 2 level as the value of results
for example for the first iteration of foo object in data
name = key(foo.bar) + key(foo)
results = value(foo.bar.baz)
name = 'barfoo'
results = [{ a: 1, b: 2, c: 3 }]
name = key(foo.baz) + key(foo)
results = value(foo.baz.bar)
name = 'bazfoo'
results = [{ a: 1, b: 2, c: 3 }]
name = key(foo.foo) + key(foo)
results = value(foo.foo.bar)
name = 'foofoo'
results = [{ a: 1, b: 2, c: 3 }]
and so with the other objects that are inside data.

I'm not sure if the structure will ever vary, but I added a few extra test cases so you can see how this will behave in some additional scenarios.
const data = {
foo: {
bar: {
baz: [{ a: 1, b: 2, c: 3 }]
},
baz: {
bar: [{ a: 1, b: 2, c: 3 }]
},
foo: {
bar: [{ a: 1, b: 2, c: 3 }]
}
},
bar: {
baz: {
bar: [{ a: 1, b: 2, c: 3 }]
}
},
baz: {
foo: {
bar: [{ a: 1, b: 2, c: 3 }]
}
},
a1: {
a2: [{ a: 1, b: 2, c: 3 }]
},
b1: [{ a: 1, b: 2, c: 3 }],
c1: {
c2: {
c3: {
c4: [{ a: 1, b: 2, c: 3 }]
}
},
c5: [{ a: 1, b: 2, c: 3 }]
},
d1: {
d2: {
d3: undefined
}
},
e1: {
e2: {
e3: null
}
},
f1: {
f2: {
// Ignored
}
}
};
function transformObject(object, name) {
if (!name) {
name = "";
}
return _.flatten(_.map(object, function(value, key) {
if (typeof value === "undefined"
|| value === null
|| _.isArray(value)) {
return {
name: name,
results: value
}
}
var objectName = key + name;
return transformObject(value, objectName);
}));
}
transformObject(data);

Related

map array of objects based on set of properties

Suppose I have an object:
let array = [
{a: 1, b: 5, c: 9},
{a: 2, b: 6, c: 10},
{a: 3, b: 7, c: 11},
{a: 4, b: 8, c: 12}
];
then I have a dictionary:
const columns = [
{ key: 'a', value: 'a' },
{ key: 'b', value: 'b' },
]
I want to filter out properties that are not defined in columns.
I have tried
array.map((x) => ({"a": x.a, "b": x.b}))
Is there a way to use the data defined in columns instead of manually typing all the properties?
Desired output:
[
{
"a": 1,
"b": 5
},
{
"a": 2,
"b": 6
},
{
"a": 3,
"b": 7
},
{
"a": 4,
"b": 8
}
]
You could map entries and get the new objects.
let
array = [{ a: 1, b: 5, c: 9 }, { a: 2, b: 6, c: 10 }, { a: 3, b: 7, c: 11 }, { a: 4, b: 8, c: 12 }],
columns = [{ key: 'a', value: 'a' }, { key: 'b', value: 'b' }],
keys = columns.map(({ key }) => key),
result = array.map(o => Object.fromEntries(keys.map(k => [k, o[k]])));
console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }
You could use this.
This uses just an array to hold the desired columns because I don't get why you would use a dictionary with key and value being the same.
let array = [
{ a: 1, b: 5, c: 9 },
{ a: 2, b: 6, c: 10 },
{ a: 3, b: 7, c: 11 },
{ a: 4, b: 8, c: 12 },
];
const desiredColumns = ["a", "b"];
const transformed = array.map(item => {
const obj = {};
desiredColumns.forEach(col => {
if(col in item){
obj[col] = item[col];
}
})
return obj;
})
console.log(array);
console.log(transformed)
Another, slightly less direct way using map() and reduce():
Create an array with all the keys we'll keep
Reduce the array to get the desired result
Add current key + value if key keep array
const array = [{a: 1, b: 5, c: 9}, {a: 2, b: 6, c: 10}, {a: 3, b: 7, c: 11}, {a: 4, b: 8, c: 12} ];
const columns = [{ key: 'a', value: 'a' }, { key: 'b', value: 'b' }, ];
const toKeep = columns.map(({ key }) => key).flat();
const result = array.map(a =>
Object.keys(a)
.reduce((prev, cur) => (toKeep.includes(cur)) ? { ...prev, [cur]: a[cur] } : prev, {})
);
console.log(result);
Result:
[
{
"a": 1,
"b": 5
},
{
"a": 2,
"b": 6
},
{
"a": 3,
"b": 7
},
{
"a": 4,
"b": 8
}
]

Sorting nested array of objects

I have an array of objects that has a nested array of objects in it. So the array looks something like:
const list = [
{
A: "a1",
B: "b1",
C: [
{
A: "a22",
B: "b12"
},
{
A: "a11",
B: "b11"
},
{
A: "a10",
B: "b10"
}
]
},
{
A: "a2",
B: "b2",
C: [
{
A: "a10",
B: "b10"
},
{
A: "a01",
B: "b01"
}
]
},
{
A: "a0",
B: "b0",
C: [
{
A: "a22",
B: "b22"
},
{
A: "a21",
B: "b21"
},
{
A: "a20",
B: "b20"
}
]
}
];
As can be seen I have an array of objects and each object as one or more fields that is also an array of objects. I can sort the array of objects based on one of the keys and it works just fine. What I want to do is sort by one of the keys in the nested array. For example sorting on C.A would yield something like (expected):
[
{
A: "a0",
B: "b0",
C: [
{
A: "a22",
B: "b22"
},
{
A: "a21",
B: "b21"
},
{
A: "a20",
B: "b20"
}
]
},
{
A: "a1",
B: "b1",
C: [
{
A: "a12",
B: "b12"
},
{
A: "a11",
B: "b11"
},
{
A: "a10",
B: "b10"
}
]
},
{
A: "a2",
B: "b2",
C: [
{
A: "a10",
B: "b10"
},
{
A: "a01",
B: "b01"
}
}
];
Ideas?
The way to get one's head clear on such things is to factor out the sort functions to explicitly state the objective, like this (I think I understand the objective)...
// sort a and b by the smallest value of A in their C arrays
const myCompare = (a, b) => {
return a.minAinC.localeCompare(b.minAinC);
};
// get the lexically smallest value of A in an object's C array
const minAinC = obj => {
const minC = obj.C.reduce((acc, o) => acc.A.localeCompare(o.A) > 0 ? o : acc, obj.C[0])
return minC.A;
};
// preprocess the outer array and cache a minAinC value on each, making the next sort efficient (optional)
const data = getData()
const readyToSort = data.map(o => ({ ...o, minAinC: minAinC(o) }));
const sorted = readyToSort.sort(myCompare)
console.log(sorted)
function getData() {
return [{
A: "a1",
B: "b1",
C: [{
A: "a22",
B: "b12"
},
{
A: "a11",
B: "b11"
},
{
A: "a10",
B: "b10"
}
]
},
{
A: "a2",
B: "b2",
C: [{
A: "a10",
B: "b10"
},
{
A: "a01",
B: "b01"
}
]
},
{
A: "a0",
B: "b0",
C: [{
A: "a22",
B: "b22"
},
{
A: "a21",
B: "b21"
},
{
A: "a20",
B: "b20"
}
]
}
];
}

How to reshaping Data in Javascript from array to object without losing some of the data

I am trying to add the key to each so that I can be able to easy make a multi scatter plot in d3. . I am not sure how to do it.
EDIT: TO CLARIFY what I meant.
Data:
var dataOriginal = {
Apples: [{"A":4,"B":null,"C":null,"D":2}, {"A":5,"B":null,"C":3,"D":2}],
Oranges: [{"A":3,"B":1,"C":4,"D":4.3}],
Jackfruit: [{"A":5,"B":4,"C":4,"D":3}],
Avocado: [{"A":null,"B":33,"C":2,"D":9.66}],
Pomegranate: [{"A":5,"B":3.5,"C":null,"D":6}]
}
Function:
const data = Object.keys(dataOriginal).map((key) => {
const temp = {...dataOriginal[key]};
temp.key = key;
return temp;
});
Results:
0:
0: {A: 4, B: null, C: null, D: 2}
1: {A: 5, B: null, C: 3, D: 2}
key: "Apples"
__proto__: Object
1:
0: {A: 3, B: 1, C: 4, D: 4.3}
key: "Oranges"
__proto__: Object
2:
0: {A: 5, B: 4, C: 4, D: 3}
key: "Jackfruit"
__proto__: Object
3:
0: {A: null, B: 33, C: 2, D: 9.66}
key: "Avocado"
__proto__: Object
4: {0: {…}, key: "Pomegranate"}
Desired results
: {A: 4, B: null, C: null, D: 2, key: "Apples"}
1: {A: 3, B: 1, C: 4, D: 4.3, key: "Oranges"}
2: {A: 5, B: 4, C: 4, D: 3, key: "Jackfruit"}
3: {A: null, B: 33, C: 2, D: 9.66, key: "Avocado"}
4: {A: 5, B: 3.5, C: null, D: 6, key: "Pomegranate"}
5: {A:5,B:null,C:3,D:2, key: "Apples"}
You need to reduce the object to get a single object with added values.
const
addByKey = array => array.reduce((a, b) => {
Object.entries(b).forEach(([k, v]) => a[k] = (a[k] || 0) + v);
return a;
}, {}),
dataOriginal = { Apples: [{ A: 4, B: null, C: null, D: 2 }, { A: 5, B: null, C: 3, D: 2 }], Oranges: [{ A: 3, B: 1, C: 4, D: 4.3 }], Jackfruit: [{ A: 5, B: 4, C: 4, D: 3 }], Avocado: [{ A: null, B: 33, C: 2, D: 9.66 }], Pomegranate: [{ A: 5, B: 3.5, C: null, D: 6 }] }
data = Object.keys(dataOriginal).map((key) => ({ ...addByKey(dataOriginal[key]), key }));
console.log(data);
.as-console-wrapper { max-height: 100% !important; top: 0; }
For getting single object with same keys, you could map the objects, add the key and get a flat array.
const
dataOriginal = { Apples: [{ A: 4, B: null, C: null, D: 2 }, { A: 5, B: null, C: 3, D: 2 }], Oranges: [{ A: 3, B: 1, C: 4, D: 4.3 }], Jackfruit: [{ A: 5, B: 4, C: 4, D: 3 }], Avocado: [{ A: null, B: 33, C: 2, D: 9.66 }], Pomegranate: [{ A: 5, B: 3.5, C: null, D: 6 }] }
data = Object
.keys(dataOriginal)
.flatMap(key => dataOriginal[key].map(o => ({ ...o, key })));
console.log(data);
.as-console-wrapper { max-height: 100% !important; top: 0; }
The reason why {"A":5,"B":null,"C":3,"D":2} is missed is because, index 0 is hardcoded in the code.
const temp = {...dataOriginal[key][0]};
Alternate solution:
var dataOriginal = {
Apples: [{"A":4,"B":null,"C":null,"D":2}, {"A":5,"B":null,"C":3,"D":2}],
Oranges: [{"A":3,"B":1,"C":4,"D":4.3}],
Jackfruit: [{"A":5,"B":4,"C":4,"D":3}],
Avocado: [{"A":null,"B":33,"C":2,"D":9.66}],
Pomegranate: [{"A":5,"B":3.5,"C":null,"D":6}]
}
const myData =[]
Object.keys(dataOriginal).map((key) => {
for (let i = 0; i < dataOriginal[key].length; i++) {
myData.push({...dataOriginal[key][i], key})
}
})
console.log(myData)

Get closest greater value in multiple attributes of Array of Objects

I have this array of objects.
var priceArray = [
{ "foo": 1, "bar": 2, "price": 3 },
{ "foo": 2, "bar": 123, "price": 124 },
{ "foo": 2, "bar": 2, "price": 5 },
{ "foo": 112, "bar": 2, "price": 75 },
{ "foo": 2, "bar": 3, "price": 5 },
{ "foo": 3, "bar": 2, "price": 3 },
{ "foo": 3, "bar": 4, "price": 7 },
{ "foo": 4, "bar": 3, "price": 4 },
{ "foo": 4, "bar": 4, "price": 6 }
];
I have another array of objects.
var dataArray = [
{ foo: 0.25, bar: 1 },
{ foo: 0.5, bar: 1 },
{ foo: 1, bar: 1 },
{ foo: 1, bar: 2 },
{ foo: 2, bar: 1 },
{ foo: 2, bar: 2 },
{ foo: 2, bar: 4 },
{ foo: 3, bar: 2 },
{ foo: 4, bar: 1 },
{ foo: 4, bar: 2 },
{ foo: 4, bar: 4 },
];
I want to add price in dataArray which price row foo and bar values are closest greater in priceArray.
for example - filtered data should like this
var filterDataArray = [
{ foo: 0.25, bar: 1, price: 3 },
{ foo: 0.5, bar: 1, price: 3 },
{ foo: 1, bar: 1, price: 3 },
{ foo: 1, bar: 2, price: 3 },
{ foo: 2, bar: 1, price: 5 },
{ foo: 2, bar: 2, price: 5 },
{ foo: 2, bar: 4, price: 7 },
{ foo: 3, bar: 2, price: 3 },
{ foo: 4, bar: 1, price: 4 },
{ foo: 4, bar: 2, price: 4 },
{ foo: 4, bar: 4, price: 6 },
];
If I sort priceArray with foo and bar value with help of these codes and then filter this array with dataArray. So, I didn't get my solution. like -
priceArray = priceArray.sort(function(a, b) {
return a.foo - b.foo || a.bar - b.bar;
});
or
priceArray = _.sortBy(( _.sortBy(priceArray, 'bar')), 'foo');
or
priceArray = _.orderBy(priceArray, ['foo', 'bar'], ['asc', 'asc']);
// create new data array with price
const dataNewArray = [];
dataArray.map(dataObj => {
const dataNewObj = {};
for(const priceObject of priceArray) {
if (dataObj.foo <= priceObject.foo && dataObj.bar <= priceObject.bar) {
dataNewObj.foo = dataObj.foo;
dataNewObj.bar = dataObj.bar;
dataNewObj.price = priceObject.price;
break;
}
}
dataNewArray.push(dataNewObj);
});
but it's solution is
dataNewArray = [
{ foo: 0.25, bar: 1, price: 3 },
{ foo: 0.5, bar: 1, price: 3 },
{ foo: 1, bar: 1, price: 3 },
{ foo: 1, bar: 2, price: 3 },
{ foo: 2, bar: 1, price: 5 },
{ foo: 2, bar: 2, price: 5 },
{ foo: 2, bar: 4, price: 124 },
{ foo: 3, bar: 2, price: 3 },
{ foo: 4, bar: 1, price: 4 },
{ foo: 4, bar: 2, price: 4 },
{ foo: 4, bar: 4, price: 6 }
];
So, you can see in this object { foo: 2, bar: 4, price: 124 }, price should be 7, not 124.
How to solve my problem with help of anything js features like Lodash, or any algorithm. I tried many solutions at StackOverflow but maximum solutions for single attribute in object.
You need to sort by the geometric distance of the items and pick the first one which match.
var priceArray = [{ foo: 1, bar: 2, price: 3 }, { foo: 2, bar: 123, price: 124 }, { foo: 2, bar: 2, price: 5 }, { foo: 112, bar: 2, price: 75 }, { foo: 2, bar: 3, price: 5 }, { foo: 3, bar: 2, price: 3 }, { foo: 3, bar: 4, price: 7 }, { foo: 4, bar: 3, price: 4 }, { foo: 4, bar: 4, price: 6 }],
dataArray = [{ foo: 0.25, bar: 1 }, { foo: 0.5, bar: 1 }, { foo: 1, bar: 1 }, { foo: 1, bar: 2 }, { foo: 2, bar: 1 }, { foo: 2, bar: 2 }, { foo: 2, bar: 4 }, { foo: 3, bar: 2 }, { foo: 4, bar: 1 }, { foo: 4, bar: 2 }, { foo: 4, bar: 4 }],
result;
priceArray.sort((a, b) =>
(Math.pow(a.foo, 2) + Math.pow(a.bar, 2)) - (Math.pow(b.foo, 2) + Math.pow(b.bar, 2))
);
result = dataArray.map(({ foo, bar }) => ({
foo,
bar,
price: priceArray.find(o => o.foo >= foo && o.bar >= bar).price
}));
console.log(result); // the result
console.log(priceArray); // the sorted array
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Adding a new element to an object in an array

Lets say I have and array made up of objects:
var points = [
{ id: 1, a: 0, b: 3 },
{ id: 2, a: 4, b: -1 },
{ id: 3, a: -1, b: 5 },
{ id: 4, a: 41, b: 2 },
{ id: 5, a: 69, b: 3 },
]
I want to iterate through each item and add a + b to get a new item d. I then want to add d within each object in the array to get a new value. When I try the below, it just adds 5 extra objects rather than appending the new element (key=value, ex: d: 3) to each individual object. What am I doing wrong here?
points.forEach((item) => {
var d = Math.abs(item.x) + Math.abs(item.y);
console.log(d);
points.item.push('d: ' + d);
});
Try following
var points = [{ id: 1, a: 0, b: 3 },{ id: 2, a: 4, b: -1 },{ id: 3, a: -1, b: 5 },{ id: 4, a: 41, b: 2 },{ id: 5, a: 69, b: 3 }];
points.forEach(o => o.d = Math.abs(o.a) + Math.abs(o.b));
console.log(points);
#jcbridwe, you can use assign() method on Object to add missing property from source object to target object.
Please have a look at the below code.
Try the below code online at http://rextester.com/EPHYV10615.
var points = [
{ id: 1, a: 0, b: 3 },
{ id: 2, a: 4, b: -1 },
{ id: 3, a: -1, b: 5 },
{ id: 4, a: 41, b: 2 },
{ id: 5, a: 69, b: 3 },
]
for(var index in points){
var a = points[index].a;
var b = points[index].b;
Object.assign(points[index], {d: a+b});
}
console.log(points);
» Output
[ { id: 1, a: 0, b: 3, d: 3 },
{ id: 2, a: 4, b: -1, d: 3 },
{ id: 3, a: -1, b: 5, d: 4 },
{ id: 4, a: 41, b: 2, d: 43 },
{ id: 5, a: 69, b: 3, d: 72 } ]
Mutable approach:
points.forEach(o => o.d = o.a + o.b);
Immutable approach:
const newPoints = points.map(o => Object.assign({}, o, {d: o.a + o.b}))

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