Related
Below code which I am using for creating the new array if the id is the same in arr1 and arr2. But doesn't work since arr1 and arr2 are different. array 1 has index and arr2 is without index. screenshot for your reference. Can someone help?
Note: ID in arr1 is the same as EmpId in arr2
for(let i=0; i<arr1.length; i++) {
merged.push({
...arr1[i],
...(arr2.find((itmInner) => itmInner.id === arr1[i].id))}
);
}
console.log(merged);
Array1 looks like this :
[{"Active":1,"Id":1},
{"Active":1,"Id":3},
{"Active":1,"Id":2}]
Array2 looks something like this:
Below is the sample code on how I am framing array 2:
renderElement(activity){
var arr2 = [] ;
for(var i = 0; i < activity.length; i++) {
obj = activity[i];
if(obj.Id == 28){
fetch(geturl)
.then(function (response) {
return response.json();
})
.then(function (data) {
res = data;
arr2.push(res)
})
}
else{
// Do nothing
}
}
return arr2
}
Calling Render method like below:
outputarray = currentComponent.renderElement(activity);
console.log('output', outputarray)
Expected Output:
[{"Active":1,"Id":1,"Param1": true},
{"Active":1,"Id":3}, / Keep it as such if nothing exists in other array
{"Active":1,"Id":2, "Param2": false}]
You can try this approach instead:
Example #1
const arr1 = [
{ "Active":1, "Id":1 },
{ "Active":1, "Id":3 },
{ "Active":1, "Id":2 }
];
const arr2 = [
{
0: [
{
EmpId1: 1, Param1: true
}
]
},
{
1: [
{
EmpId2: 2,Param2: false
}
]
},
{
2: [
{
EmpId3: 2
}
]
},
];
const response = arr1
.reduce((acc, value) => {
const secondaryData = arr2.map((val, index) => {
const { [`EmpId${index + 1}`]: Id, ...others } = val[Object.keys(val)][0];
return { Id, ...others };
});
const match = secondaryData.findIndex(({ Id }) => Id === value.Id);
if (match >= 0) acc.push({...value, ...secondaryData[match]})
else acc.push(value);
return acc;
}, []);
console.log(response);
Example #2
const arr1 = [
{ "Active":1, "Id":1 },
{ "Active":1, "Id":3 },
{ "Active":1, "Id":2 }
];
const arr2 = [
[
{
EmpId1: 1,
Param1: true
}
],
[
{
EmpId2: 2,
Param2: false
}
],
[
{
EmpId3: 2
}
],
]
const response = arr1
.reduce((acc, value) => {
const secondaryData = arr2.map(([val], index) => {
const { [`EmpId${index + 1}`]: Id, ...others } = val;
return { Id, ...others };
});
const match = secondaryData.findIndex(({ Id }) => Id === value.Id);
if (match >= 0) acc.push({...value, ...secondaryData[match]})
else acc.push(value);
return acc;
}, []);
console.log(response);
Basically you can create a hash map by a object property and join on that property all the arrays, i.e. reduce an array of arrays into a result object, then convert the object's values back to an array. Since each array is reduced this means each array is only traversed once O(n) and the map object provides constant time O(1) lookup to match objects. This keeps the solution closer to O(n) rather than other solutions with a nested O(n) findIndex search, which yields a solution closer to O(n^2).
const mergeByField = (...arrays) => {
return Object.values(
arrays.reduce(
(result, { data, field }) => ({
...data.flat().reduce(
(obj, el) => ({
...obj,
[el[field]]: {
...obj[el[field]],
...el
}
}),
result
)
}),
{}
)
);
};
Load each array into a payload object that specifies the field key to match on. This will return all fields used to match by, but these can safely be ignored later, or removed, whatever you need. Example:
mergeByField(
{ data: arr1, field: "Id" },
{ data: arr2, field: "EmpId" },
);
const arr1 = [
{
Active: 1,
Id: 1
},
{
Active: 1,
Id: 2
},
{
Active: 1,
Id: 3
}
];
const arr2 = [[{ EmpId: 1, Param1: true }], [{ EmpId: 3, Param2: false }]];
const mergeByField = (...arrays) => {
return Object.values(
arrays.reduce(
(result, { data, field }) => ({
...data.flat().reduce(
(obj, el) => ({
...obj,
[el[field]]: {
...obj[el[field]],
...el
}
}),
result
)
}),
{}
)
);
};
console.log(
mergeByField({ data: arr1, field: "Id" }, { data: arr2, field: "EmpId" })
);
I have an array which I need to combine with comma-separated of the same level and form a new array.
Input:
let arr = [
[{ LEVEL: 1, NAME: 'Mark' }, { LEVEL: 1, NAME: 'Adams' }, { LEVEL: 2, NAME: 'Robin' }],
[{ LEVEL: 3, NAME: 'Williams' }],
[{ LEVEL: 4, NAME: 'Matthew' }, { LEVEL: 4, NAME: 'Robert' }],
];
Output
[
[{ LEVEL: 1, NAME: 'Mark,Adams' }, { LEVEL: 2, NAME: 'Robin' }],
[{ LEVEL: 3, NAME: 'Williams' }],
[{ LEVEL: 4, NAME: 'Matthew,Robert' }],
];
I tried with the following code but not getting the correct result
let finalArr = [];
arr.forEach(o => {
let temp = finalArr.find(x => {
if (x && x.LEVEL === o.LEVEL) {
x.NAME += ', ' + o.NAME;
return true;
}
if (!temp) finalArr.push(o);
});
});
console.log(finalArr);
You could map the outer array and reduce the inner array by finding the same level and add NAME, if found. Otherwise create a new object.
var data = [[{ LEVEL: 1, NAME: "Mark" }, { LEVEL: 1, NAME: "Adams" }, { LEVEL: 2, NAME: "Robin"}], [{ LEVEL: 3, NAME: "Williams" }], [{ LEVEL: 4, NAME: "Matthew" }, { LEVEL: 4, NAME: "Robert" }]],
result = data.map(a => a.reduce((r, { LEVEL, NAME }) => {
var temp = r.find(q => q.LEVEL === LEVEL);
if (temp) temp.NAME += ',' + NAME;
else r.push({ LEVEL, NAME });
return r;
}, []));
console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }
Assuming you only want to merge within the same array and not across arrays, and assuming there aren't all that many entries (e.g., fewer than several hundred thousand), the simple thing is to build a new array checking to see if it already has the same level in it:
let result = arr.map(entry => {
let newEntry = [];
for (const {LEVEL, NAME} of entry) {
const existing = newEntry.find(e => e.LEVEL === LEVEL);
if (existing) {
existing.NAME += "," + NAME;
} else {
newEntry.push({LEVEL, NAME});
}
}
return newEntry;
});
let arr= [
[{"LEVEL":1,"NAME":"Mark"},
{"LEVEL":1,"NAME":"Adams"},
{"LEVEL":2,"NAME":"Robin"} ],
[{"LEVEL":3,"NAME":"Williams"}],
[{"LEVEL":4,"NAME":"Matthew"},
{"LEVEL":4,"NAME":"Robert"}]
];
let result = arr.map(entry => {
let newEntry = [];
for (const {LEVEL, NAME} of entry) {
const existing = newEntry.find(e => e.LEVEL === LEVEL);
if (existing) {
existing.NAME += "," + NAME;
} else {
newEntry.push({LEVEL, NAME});
}
}
return newEntry;
});
console.log(result);
If the nested arrays can be truly massively long, you'd want to build a map rather than doing the linear search (.find) each time.
I'd try to do as much of this in constant time as possible.
var m = new Map();
array.forEach( refine.bind(m) );
function refine({ LABEL, NAME }) {
var o = this.get(NAME)
, has = !!o
, name = NAME
;
if (has) name = `${NAME}, ${o.NAME}`;
this.delete(NAME);
this.set(name, { NAME: name, LABEL });
}
var result = Array.from( m.values() );
I haven't tested this as I wrote it on my phone at the airport, but this should at least convey the approach I would advise.
EDIT
Well... looks like the question was edited... So... I'd recommend adding a check at the top of the function to see if it's an array and, if so, call refine with an early return. Something like:
var m = new Map();
array.forEach( refine.bind(m) );
function refine(item) {
var { LABEL, NAME } = item;
if (!NAME) return item.forEach( refine.bind(this) ); // assume array
var o = this.get(NAME)
, has = !!o
, name = NAME
;
if (has) name = `${NAME}, ${o.NAME}`;
this.delete(NAME);
this.set(name, { NAME: name, LABEL });
}
var result = Array.from( m.values() );
That way, it should work with both your original question and your edit.
EDIT
Looks like the question changed again... I give up.
Map the array values: every element to an intermediate object, then create the desired object from the resulting entries:
const basicArr = [
[{"LEVEL":1,"NAME":"Mark"},
{"LEVEL":1,"NAME":"Adams"},
{"LEVEL":2,"NAME":"Robin"} ],
[{"LEVEL":3,"NAME":"Williams"}],
[{"LEVEL":4,"NAME":"Matthew"},
{"LEVEL":4,"NAME":"Robert"}]
];
const leveled = basicArr.map( val => {
let obj = {};
val.forEach(v => {
obj[v.LEVEL] = obj[v.LEVEL] || {NAME: []};
obj[v.LEVEL].NAME = obj[v.LEVEL].NAME.concat(v.NAME);
});
return Object.entries(obj)
.map( ([key, val]) => ({LEVEL: +key, NAME: val.NAME.join(", ")}));
}
);
console.log(leveled);
.as-console-wrapper { top: 0; max-height: 100% !important; }
if you want to flatten all levels
const basicArr = [
[{"LEVEL":1,"NAME":"Mark"},
{"LEVEL":1,"NAME":"Adams"},
{"LEVEL":2,"NAME":"Robin"} ],
[{"LEVEL":3,"NAME":"Williams"}],
[{"LEVEL":4,"NAME":"Matthew"},
{"LEVEL":4,"NAME":"Robert"},
{"LEVEL":2,"NAME":"Cynthia"}],
[{"LEVEL":3,"NAME":"Jean"},
{"LEVEL":4,"NAME":"Martha"},
{"LEVEL":2,"NAME":"Jeff"}],
];
const leveled = basicArr.map( val => Object.entries (
val.reduce( (acc, val) => {
acc[val.LEVEL] = acc[val.LEVEL] || {NAME: []};
acc[val.LEVEL].NAME = acc[val.LEVEL].NAME.concat(val.NAME);
return acc;
}, {}))
.map( ([key, val]) => ({LEVEL: +key, NAME: val.NAME.join(", ")})) )
.flat() // (use .reduce((acc, val) => acc.concat(val), []) for IE/Edge)
.reduce( (acc, val) => {
const exists = acc.filter(x => x.LEVEL === val.LEVEL);
if (exists.length) {
exists[0].NAME = `${val.NAME}, ${exists.map(v => v.NAME).join(", ")}`;
return acc;
}
return [... acc, val];
}, [] );
console.log(leveled);
.as-console-wrapper { top: 0; max-height: 100% !important; }
ES6 way:
let say attributes is multidimensional array having multimple entries which need to combine like following:
let combinedArray = [];
attributes.map( attributes => {
combined = combinedArray.concat(...attributes);
});
I have a function called tree, which takes array of objects (as data fields from a database) and array of strings for keys. The function loops through rowsArray and recursively creates object with nested properties based on keyArray.
const tree = (rowsArray, keysArray) => {
return rows.reduce((acc, row) => {
const groupBy = (row, keys,) => {
const [first, ...rest] = keys;
if (!first) return [row];
return {
[row[first]]: groupBy(row, rest),
}
};
acc = {...groupBy(row, keys), ...acc};
return acc;
}, {});
}
The data is following:
const data = [{
ID: 1,
Main: "Financial",
Sub: "Forecasts",
Detail: "General"
}, {
ID: 2,
Main: "Financial",
Sub: "HR",
Detail: "Headcount"
}];
const result1 = tree(data, ["Main", "Sub", "Detail"]);
console.log(result1);
When I log the result, I get:
/*
// actual output
{
Financial: {
Forecasts: {
General: [Array]
}
}
}
Whereas, I would like to get following:
// expected
{
Financial: {
Forecasts: {
General: [Array]
},
HR: {
Headcount: [Array]
}
}
}
*/
The problem is, that acc variable in main function gets overridden and I get new object, instead of accumulative and I am not quite sure how to recursively build this object. I tried to pass instances of acc to groupBy function (to remember previous results), but no luck.
Do you have any idea how I could rewrite tree function or groupBy function to accomplish my goal? Thanks!
You could do it like this:
function tree(rows, keys) {
return rows.reduce( (acc, row) => {
keys.reduce( (parent, key, i) =>
parent[row[key]] = parent[row[key]] || (i === keys.length - 1 ? [row] : {})
, acc);
return acc;
}, {});
}
const data = [{ID: 1,Main: "Financial",Sub: "Forecasts",Detail: "General"}, {ID: 2,Main: "Financial",Sub: "HR", Detail: "Headcount" }];
const result1 = tree(data, ["Main", "Sub", "Detail"]);
console.log(result1);
Be aware that the spread syntax makes a shallow copy. Instead, in this solution, the accumulator is passed to the inner reduce. And so we actually merge the new row's hierarchical data into the accumulator on-the-spot.
The problem is your merge function is not deep. When you assign the values to the accumulator you overwrite existing properties - in this case Financial.
I included a deep merge function from here and now it works.
I also fixed some reference errors you had:
rows => rowsArray
keys = keysArray
// deep merge function
function merge(current, update) {
Object.keys(update).forEach(function(key) {
// if update[key] exist, and it's not a string or array,
// we go in one level deeper
if (current.hasOwnProperty(key) &&
typeof current[key] === 'object' &&
!(current[key] instanceof Array)) {
merge(current[key], update[key]);
// if update[key] doesn't exist in current, or it's a string
// or array, then assign/overwrite current[key] to update[key]
} else {
current[key] = update[key];
}
});
return current;
}
const tree = (rowsArray, keysArray) => {
return rowsArray.reduce((acc, row) => {
const groupBy = (row, keys, ) => {
const [first, ...rest] = keys;
if (!first) return [row];
return {
[row[first]]: groupBy(row, rest),
}
};
acc = merge(groupBy(row, keysArray), acc);
return acc;
}, {});
}
const data = [{
ID: 1,
Main: "Financial",
Sub: "Forecasts",
Detail: "General"
}, {
ID: 2,
Main: "Financial",
Sub: "HR",
Detail: "Headcount"
}];
const result1 = tree(data, ["Main", "Sub", "Detail"]);
console.log(result1);
You could iterate the keys and take either an object for not the last key or an array for the last key and push then the data to the array.
const tree = (rowsArray, keysArray) => {
return rowsArray.reduce((acc, row) => {
keysArray
.map(k => row[k])
.reduce((o, k, i, { length }) => o[k] = o[k] || (i + 1 === length ? []: {}), acc)
.push(row);
return acc;
}, {});
}
const data = [{ ID: 1, Main: "Financial", Sub: "Forecasts", Detail: "General" }, { ID: 2, Main: "Financial", Sub: "HR", Detail: "Headcount" }];
const result1 = tree(data, ["Main", "Sub", "Detail"]);
console.log(result1);
.as-console-wrapper { max-height: 100% !important; top: 0; }
You can iterate over the data and created a unique key based on the keys provided and then recursively generate the output structure by deep cloning.
const data = [{
ID: 1,
Main: "Financial",
Sub: "Forecasts",
Detail: "General"
}, {
ID: 2,
Main: "Financial",
Sub: "HR",
Detail: "Headcount"
}];
function generateKey(keys,json){
return keys.reduce(function(o,i){
o += json[i] + "_";
return o;
},'');
}
function merge(first,second){
for(var i in second){
if(!first.hasOwnProperty(i)){
first[i] = second[i];
}else{
first[i] = merge(first[i],second[i]);
}
}
return first;
}
function generateTree(input,keys){
let values = input.reduce(function(o,i){
var key = generateKey(keys,i);
if(!o.hasOwnProperty(key)){
o[key] = [];
}
o[key].push(i);
return o;
},{});
return Object.keys(values).reduce(function(o,i){
var valueKeys = i.split('_');
var oo = {};
for(var index = valueKeys.length -2; index >=0 ;index--){
var out = {};
if(index === valueKeys.length -2){
out[valueKeys[index]] = values[i];
}else{
out[valueKeys[index]] = oo;
}
oo = out;
}
o = merge(o,oo);
return o;
},{});
}
console.log(generateTree(data,["Main", "Sub", "Detail"]));
jsFiddle Demo - https://jsfiddle.net/6jots8Lc/
I need to transmit some data, that has too many key-value pairs.
As the keys are similar, I dont want to transmit them with each object.
Consider I have the following data:
[
{
x:11,
y:12
},{
x:21,
y:22
},{
x:31,
y:32
},{
x:41,
y:42
}
];
And I need the final output as
[ [x,y],[[11,12],[21,22],[31,32],[41,42]] ] OR
[ [x,y],[11,12],[21,22],[31,32],[41,42] ]
On the other end, I should be able to convert back to its original form.
It would be great if it can handle an additional key in some of the objects
I think I have seen lodash or underscore function for something close/similar to this, but I'm not able to find it right now.
NOTE: I don't know what the keys will be
Lodash v4.17.1
modify original
var modifiedOriginal = _.chain(original)
.map(_.keys)
.flatten()
.uniq()
.thru(function(header){
return _.concat(
[header],
_.map(original, function(item) {
return _.chain(item)
.defaults(_.zipObject(
header,
_.times(_.size(header), _.constant(undefined))
))
.pick(header)
.values()
.value()
})
);
})
.value();
modified back to original (keys order is not
guarantee)
var backToOriginal = _.map(_.tail(modified), function(item) {
return _.chain(_.head(modified))
.zipObject(item)
.transform(function(result, val, key) {
if (!_.isUndefined(val)) {
result[key] = val;
}
})
.value();
});
JSFiddle code https://jsfiddle.net/wa8kaL5g/1/
Using Array#reduce
var arr = [{
x: 11,
y: 12
}, {
x: 21,
y: 22
}, {
x: 31,
y: 32
}, {
x: 41,
y: 42
}];
var keys = Object.keys(arr[0]);
var op = arr.reduce(function(a, b) {
var arr = keys.reduce(function(x, y) {
return x.concat([b[y]]);
}, [])
return a.concat([arr]);
}, [keys]); //If all the objects are having identical keys!
console.log(JSON.stringify(op));
A little more verbose way of doing it:
[Edit: added the function to convert it back]
function convert(arr) {
var retArr = [ [/* keys (retArr[0]) */], [/* values (retArr[1]) */] ]
arr.forEach(function(obj){
// create new array for new sets of values
retArr[1].push([])
// put all of the keys in the correct array
for (var key in obj) {
if (obj.hasOwnProperty(key)) {
// does the key exist in the array yet?
if (retArr[0].indexOf(key) === -1) {
retArr[0].push(key)
}
// get last index of retArr[1] and push on the values
retArr[1][retArr[1].length - 1].push(obj[key])
}
}
})
return retArr
}
function reConvert(arr) {
var retArr = []
var keys = arr[0]
arr[1].forEach(function(itemArr){
var obj = {}
itemArr.forEach(function(item, i){
obj[keys[i]] = item
})
retArr.push(obj)
})
return retArr
}
var objArr = [
{
x:11,
y:12
},{
x:21,
y:22
},{
x:31,
y:32
},{
x:41,
y:42
}
]
var arrFromObj = convert(objArr)
var objFromArr = reConvert(arrFromObj)
console.log(arrFromObj)
console.log(objFromArr)
A solution using Underscore.
First work out what the keys are:
var keys = _.chain(data)
.map(_.keys)
.flatten()
.uniq()
.value();
Then map across the data to pick out the value for each key:
var result = [
keys,
_.map(data, item => _.map(keys, key => item[key]))
];
and back again:
var thereAndBackAgain = _.map(result[1], item => _.omit(_.object(result[0], item), _.isUndefined));
Lodash's version of object is zipObject and omit using a predicate is omitBy:
var thereAndBackAgain = _.map(result[1], item => _.omitBy(_.zipObject(result[0], item), _.isUndefined));
var data = [
{
x:11,
y:12,
aa: 9
},{
x:21,
y:22
},{
x:31,
y:32,
z: 0
},{
x:41,
y:42
}
];
var keys = _.chain(data)
.map(_.keys)
.flatten()
.uniq()
.value();
var result = [
keys,
_.map(data, item => _.map(keys, key => item[key]))
];
var thereAndBackAgain = _.map(result[1], item => _.omit(_.object(result[0], item), _.isUndefined));
console.log(result)
console.log(thereAndBackAgain)
<script src="
https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script>
In ES6 you can do it by reducing it with Object.values(), and Object.keys(). You can restore it using a combination of Array.prototype.map() and Array.prototype.reduce():
const convertStructure = (data) => data.reduce((s, item) => {
s[1].push(Object.values(item));
return s;
}, [Object.keys(data[0]), []]); // all objects should be the same, so we can take the keys from the 1st object
const restoreStructure = ([keys, data]) => data.map((item) => item.reduce((o, v, i) => {
o[keys[i]] = v;
return o;
}, {}));
const data = [{
x: 11,
y: 12
}, {
x: 21,
y: 22
}, {
x: 31,
y: 32
}, {
x: 41,
y: 42
}];
const convertedStructure = convertStructure(data);
console.log('convertedStructure:\n', convertedStructure);
const restoredStructure = restoreStructure(convertedStructure);
console.log('restoredStructure:\n', restoredStructure);
For a nested complex object or array, I would like to collect all values for a given property name. Example:
var structure = {
name: 'alpha',
array: [
{ name: 'beta' },
{ name: 'gamma' }
],
object: {
name: 'delta',
array: [
{ name: 'epsilon' }
]
}
};
// expected result: [ 'alpha', 'beta', 'gamma', 'delta', 'epsilon' ]
It's obvious how to achieve this using plain JS, but: Is there any elegant, concise approach using lodash?
[edit] Current variant below. Nicer solutions welcome!
function getPropertyRecursive(obj, property) {
var values = [];
_.each(obj, function(value, key) {
if (key === property) {
values.push(value);
} else if (_.isObject(value)) {
values = values.concat(getPropertyRecursive(value, property));
}
});
return values;
}
This can be done elegantly with the following mixin, which is a recursive version of _.toPairs:
_.mixin({
toPairsDeep: obj => _.flatMap(
_.toPairs(obj), ([k, v]) =>
_.isObjectLike(v) ? _.toPairsDeep(v) : [[k, v]])
});
then to get the result you want:
result = _(structure)
.toPairsDeep()
.map(1)
.value()
If there are scalar properties other than name, you'll have to filter them out:
result = _(structure)
.toPairsDeep()
.filter(([k, v]) => k === 'name')
.map(1)
.value()
There's no Lodash/Underscore function that I know if that will do what you're looking for.
So what are you looking to do? Well, specifically you're looking to extract the values of all of the name properties out of a aggregate structure. How would we generalize that? In other words, if you were looking to add such functionality to Lodash/Underscore, how would you reframe the problem? After all, most people don't want to get the values of the name properties. You could create a generic function where you supply the name of the property you want, but...thinking even more abstractly than that, what you really want to do is visit all of the nodes in a aggregate structure and do something with them. If we consider aggregate structures in JavaScript as generic trees, we can take a recursive approach using a depth-first walk:
function walk(o, f) {
f(o);
if(typeof o !== 'object') return;
if(Array.isArray(o))
return o.forEach(e => walk(e, f));
for(let prop in o) walk(o[prop], f);
}
Now we can do what you're looking for by walking the structure and adding things to an array:
const arr = [];
walk(structure, x => if(x !== undefined && x.name) arr.push(x.name));
This isn't quite functional enough for my tastes, though...there's a side effect on arr here. So an even better generic approach (IMO) would be to allow a context object to ride along (or an accumulator if you will, a la Array#reduce):
function walk(o, f, context) {
f(o, context);
if(typeof o !== 'object') return context;
if(Array.isArray(o)) return o.forEach(e => walk(e, f, context)), context;
for(let prop in o) walk(o[prop], f, context);
return context;
}
Now you can call it like this, side-effect free:
const arr = walk(structure, (x, context) => {
if(x !== undefined && x.name) context.push(x.name);
}, []);
Iterate the object recursively using _.reduce():
function getPropertyRecursive(obj, prop) {
return _.reduce(obj, function(result, value, key) {
if (key === prop) {
result.push(value);
} else if (_.isObjectLike(value)) {
return result.concat(getPropertyRecursive(value, prop));
}
return result;
}, []);
}
var structure = {
name: 'alpha',
array: [{
name: 'beta'
}, {
name: 'gamma'
}],
object: {
name: 'delta',
array: [{
name: 'epsilon'
}]
}
};
var result = getPropertyRecursive(structure, 'name');
console.log(result);
<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.16.2/lodash.min.js"></script>
You could iterate the object and call it again for arrays or objects. Then get the wanted property.
'use strict';
function getProperty(object, key) {
function iter(a) {
var item = this ? this[a] : a;
if (this && a === key) {
return result.push(item);
}
if (Array.isArray(item)) {
return item.forEach(iter);
}
if (item !== null && typeof item === 'object') {
return Object.keys(item).forEach(iter, item);
}
}
var result = [];
Object.keys(object).forEach(iter, object);
return result;
}
var structure = { name: 'alpha', array: [{ name: 'beta' }, { name: 'gamma' }], object: { name: 'delta', array: [{ name: 'epsilon' }] } };
console.log(getProperty(structure,'name'));
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Based on the answer ( https://stackoverflow.com/a/39822193/3443096 ) , here's another idea for mixin:
_.mixin({
extractLeaves: (obj, filter, subnode, subpathKey, rootPath, pathSeparator) => {
var filterKv = _(filter).toPairs().flatMap().value()
var arr = _.isArray(obj) ? obj : [obj]
return _.flatMap(arr, (v, k) => {
if (v[filterKv[0]] === filterKv[1]) {
var vClone = _.clone(v)
delete vClone[subnode]
vClone._absolutePath = rootPath + pathSeparator + vClone[subpathKey]
return vClone
} else {
var newRootPath = rootPath
if (_.isArray(obj)) {
newRootPath = rootPath + pathSeparator + v[subpathKey]
}
return _.extractLeaves(
v[subnode], filter, subnode,
subpathKey, newRootPath, pathSeparator
)
}
})
}
});
This work for this example JSON, where you want to extract leaf-nodes:
{
"name": "raka",
"type": "dir",
"children": [{
"name": "riki",
"type": "dir",
"children": [{
"name": "roko",
"type": "file"
}]
}]
}
Use it this way:
_.extractLeaves(result, {type: "file"}, "children", "name", "/myHome/raka", "/")
And you will get:
[
{
"name": "roko",
"type": "file",
"_absolutePath": "/myHome/raka/riki/roko"
}
]