Sorry if this has been asked before. I have the JSON structure like:
{"data":[
{"Date":"03/04/2016","Key":"A","Values":"123"},
{"Date":"04/04/2016","Key":"A","Values":"456"},
{"Date":"03/04/2016","Key":"B","Values":"789"},
{"Date":"04/04/2016","Key":"B","Values":"012"}
]}
I want to change this to a different format which is basically grouped by Key and combines rest of the field in Values
{"Result":[
{
"Key":"A"
"Values":[["03/04/2016","123"], ["04/04/2016","456"]]
},
{"Key":"B"
"Values":[["03/04/2016","789"]},["04/04/2016","012"]]
}
]}
I want to do this javascript/html
You could iterate and build a new object if not exist.
var object = { "data": [{ "Date": "03/04/2016", "Key": "A", "Values": "123" }, { "Date": "04/04/2016", "Key": "A", "Values": "456" }, { "Date": "03/04/2016", "Key": "B", "Values": "789" }, { "Date": "04/04/2016", "Key": "B", "Values": "012" }], result: [] };
object.data.forEach(function (a) {
if (!this[a.Key]) {
this[a.Key] = { Key: a.Key, Values: [] };
object.result.push(this[a.Key]);
}
this[a.Key].Values.push([a.Date, a.Values]);
}, Object.create(null));
console.log(object);
I think this can be a better answer (but Nina's answer is the match for your problem terms) if items of data array have different properties and you don't want to change input data.
var raw = {"data":[
{"Date":"03/04/2016","Key":"A","Values":"123"},
{"Date":"04/04/2016","Key":"A","Values":"456"},
{"Date":"03/04/2016","Key":"B","Values":"789"},
{"Date":"04/04/2016","Key":"B","Values":"012"}
]};
var result = new Map;
raw.data.forEach(entry => {
var key = entry.Key;
if (this[key])
return this[key].push(getClonedData(entry));
this[key] = [getClonedData(entry)];
result.set(key, {
Key: key,
Values: this[key]
})
}, Object.create(null));
var filtered = {
result: [...result.values()]
}
console.log(filtered);
function getClonedData(entry) {
data = Object.assign({}, entry);
delete data.Key;
return data;
}
Related
I have an array of values as follows
[
{
"factor": {
"data": "f1",
"val": [
"val1"
]
}
},
{
"factor": {
"data": "f2",
"val": [
"val2"
]
}
}
]
Is there a way to convert it to below format
{
"keyvalue": {
"factor": {
"data": "f1",
"val": ["val1"]
},
"factor": {
"data": "f2",
"val": ["val2"]
}
}
}
Standard array parsing to object doesn't work in this case given keys has to be unique
It's impossible. Every key in the object has to be unique. To understand this, imagine you have an object with two identical keys:
const obj = {
"key": 1,
"key": 2
}
But what you should receive when you use an expression like obj.key? 1 or 2? It's nonsense.
You should rethink your object structure, maybe you need an array of objects?
{
"keyvalue": {
"factor": [
{
"data": "f1",
"val": ["val1"]
},
{
"data": "f2",
"val": ["val2"]
}
]
}
}
What you can do is use the data field as a key given it's always unique.
Something like this :
{
"factor": {
"f1": ["val1"],
"f2": ["val2"]
}
}
Here's how you would proceed to transform the array to the key/value object :
let keyValue = {"factor": {}};
theArray.forEach((item) => {
const key = item.factor.data;
const value = item.factor.val;
keyValue.factor[key] = value;
});
now the keyValue object is as described.
I have this nested object (json):
const json = {
"application": {
"App1": {
"cats": [
1
]
},
"App2": {
"cats": [
3
]
},
"App3": {
"cats": [
1,
2
]
}
},
"categories": {
"1": {
"name": "FirstCategory"
},
"2": {
"name": "SecondCategory"
},
"3": {
"name": "ThirdCategory"
}
}
};
This object has two main properties: application and categories.
I want to map over application's cats array and get name property of each element of cats array.
So the final result should look like:
{
"App1": "FirstCategory",
"App2": "ThirdCategory",
"App3": "FirstCategory, ThirdCategory"
}
I have tried to use map function, but the main difficulty is that inside applicaiton property cats is array (can have multiple values). So the code below didn't work:
Object.values(json.application).map(val => {
Object.keys(json.categories).map(key => {
//print something
});
});
You can use Array.reduce for an elegant solution.
const json = {
"application": {
"App1": {
"cats": [
1
]
},
"App2": {
"cats": [
3
]
},
"App3": {
"cats": [
1,
2
]
}
},
"categories": {
"1": {
"name": "FirstCategory"
},
"2": {
"name": "SecondCategory"
},
"3": {
"name": "ThirdCategory"
}
}
};
//Getting Application object
const application = json.application
//Getting Categories object
const categories = json.categories
//initializing reduce with a blank object and pushing all the keys of the application object
//Looping over keys of application object
const requiredOutput = Object.keys(application).reduce((out, appKey) => {
//Setting value based on categories name
out[appKey] = application[appKey].cats.map(id => categories[id].name)
return out
}, {})
console.log(requiredOutput)
PS: You can refer this gist for safe reading from a nested object.
Try it with this.
for(let val in json.application){
json.application[val] = json.application[val].cats.map(cat => json.categories[cat].name).join(",")
}
const result = Object.keys(json.application).reduce((a,key) => {
a[key] = json.application[key].cats
.map(cat => json.categories[cat].name)
.join(", ")
return a;
}, {})
loop over keys of application
for each key loop over car, and for each cat return string value from category
join list of cat strings
By using underscoreJS lib and manipulating some datas, i have this object
var data = {
"2017-09-26": [
{
"id": 274281,
"value": 10
},
{
"id": 274282,
"value": 20
}],
"2017-09-27": [
{
"id": 274281,
"value": 12
},
{
"id": 274282,
"value": 13
}],
}
i would like to obtain this result below by passing the keys as date in the child object and transform the value of id key as the new key of the value of value
var data = [{
date:"2017-09-26",
274281: 10,
274282: 20
},
{
date:"2017-09-27",
274281: 12,
274282: 13
}]
Please does someone as an idea to help me to do this and ideally efficiently?
Thanks
Here it is in one line:
Object.keys(data).map(key => ({date: key, ...data[key].reduce((p, c) => {p[c.id] = c.value; return p}, {})}))
Result:
[{
"274281":10,
"274282":20,
"date":"2017-09-26"
},
{
"274281":12,
"274282":13,
"date":"2017-09-27"
}]
You need nested loops. The first level creates the objects with the date property, then you loop over the objects in that value, and add the id: value properties to the result.
var newdata = _.map(data, (date, objects) => {
res = {date: date};
_.each(objects, obj => {
res[obj.id] = obj.value;
});
return res;
});
You can use Array.from() on the result of Object.entries(data) to create an array of objects by passing a callback function as the second argument.
Then for each sub-array, use .reduce() to create a new object from its members.
var data = {
"2017-09-26": [
{ "id": 274281, "value": 10 },
{ "id": 274282, "value": 20 }
],
"2017-09-27": [
{ "id": 274281, "value": 12 },
{ "id": 274282, "value": 13 }
],
};
const result = Array.from(Object.entries(data), ([key, arr]) =>
arr.reduce((res, {id, value}) =>
Object.assign(res, {[id]: value})
, {date: key})
);
console.log(result);
Here's one that's just about the same, but uses the new object literal spread syntax.
var data = {
"2017-09-26": [
{ "id": 274281, "value": 10 },
{ "id": 274282, "value": 20 }
],
"2017-09-27": [
{ "id": 274281, "value": 12 },
{ "id": 274282, "value": 13 }
],
};
const result = Array.from(Object.entries(data), ([key, arr]) =>
({date: key,
...Object.assign({}, ...arr.map(({id, value}) => ({[id]: value})))
})
);
console.log(result);
I have the following Json
var myjson = [{
"files": [
{
"domain": "d",
"units": [
{
"key": "key1",
"type": "2"
},
{
"key": "key2",
"type": "2"
},
{
"key": "key3",
"type": "2"
}]
},
{
"domain": "d1",
"units": [
{
"key": "key11",
"type": "2"
},
{
"key": "key12",
"type": "2"
},
{
"key": "key13",
"type": "2"
}]
}]
},
{
"files": [
{
"domain": "d",
"units": [
{
......
I want to create an new array from this Json array. The length of array will be the number of "units" in this Json object.
So I need to extract "units" and add some data from parent objects.
units: [{
domain: "",
type: "",
key: ""
}, {
domain: "",
type: "",
key: ""
},
{
domain: "",
type: "",
key: ""
}
....
];
I guess i can probably do something like this:
var res = [];
myjson.forEach(function(row) {
row.files.forEach(function(tfile) {
tfile.units.forEach(function(unit) {
var testEntity = {
domain: tfile.domain,
type : unit.type,
key: unit.key
};
res.push(testEntity);
});
});
});
But it is difficult to read and looks not so good. I was thinking to do something like :
var RESULT = myjson.map(function(row) {
return row.files.map(function(tfile) {
return tfile.units.map(function(unit) {
return {
domain: tfile.domain,
type : unit.type,
key: unit.key
};
});
});
});
But This doesn't work and looks not better . Is there any way to do so it works, maybe in more declarative way. hoped Ramda.js could help.
It there any good approach in general to get data from any Nested json in readable way?
Implementing something like:
nestedjson.findAllOnLastlevel(function(item){
return {
key : item.key,
type: type.key,
domain : item.parent.domain}
});
Or somehow flatten this json so all properties from all parents object are moved to leafs children. myjson.flatten("files.units")
jsbin http://jsbin.com/hiqatutino/edit?css,js,console
Many thanks
The function you can use here is Ramda's R.chain function rather than R.map. You can think of R.chain as a way of mapping over a list with a function that returns another list and then flattens the resulting list of lists together.
// get a list of all files
const listOfFiles =
R.chain(R.prop('files'), myjson)
// a function that we can use to add the domain to each unit
const unitsWithDomain =
(domain, units) => R.map(R.assoc('domain', domain), units)
// take the list of files and add the domain to each of its units
const result =
R.chain(file => unitsWithDomain(file.domain, file.units), listOfFiles)
If you wanted to take it a step further then you could also use R.pipeK which helps with composing functions together which behave like R.chain between each of the given functions.
// this creates a function that accepts the `myjson` list
// then passes the list of files to the second function
// returning the list of units for each file with the domain attached
const process = pipeK(prop('files'),
f => map(assoc('domain', f.domain), f.units))
// giving the `myjson` object produces the same result as above
process(myjson)
Pure JS is very sufficient to produce the result in simple one liners. I wouldn't touch any library just for this job. I have two ways to do it here. First one is a chain of reduce.reduce.map and second one is a chain of reduce.map.map. Here is the code;
var myjson = [{"files":[{"domain":"d","units":[{"key":"key1","type":"2"},{"key":"key2","type":"2"},{"key":"key3","type":"2"}]},{"domain":"d1","units":[{"key":"key11","type":"2"},{"key":"key12","type":"2"},{"key":"key13","type":"2"}]}]},{"files":[{"domain":"e","units":[{"key":"key1","type":"2"},{"key":"key2","type":"2"},{"key":"key3","type":"2"}]},{"domain":"e1","units":[{"key":"key11","type":"2"},{"key":"key12","type":"2"},{"key":"key13","type":"2"}]}]}],
units = myjson.reduce((p,c) => c.files.reduce((f,s) => f.concat(s.units.map(e => (e.domain = s.domain,e))) ,p) ,[]);
units2 = myjson.reduce((p,c) => p.concat(...c.files.map(f => f.units.map(e => (e.domain = f.domain,e)))) ,[]);
console.log(units);
console.log(units2);
For ES5 compatibility i would suggest the reduce.reduce.map chain since there is no need for a spread operator. And replace the arrow functions with their conventional counterparts like the one below;
var myjson = [{"files":[{"domain":"d","units":[{"key":"key1","type":"2"},{"key":"key2","type":"2"},{"key":"key3","type":"2"}]},{"domain":"d1","units":[{"key":"key11","type":"2"},{"key":"key12","type":"2"},{"key":"key13","type":"2"}]}]},{"files":[{"domain":"e","units":[{"key":"key1","type":"2"},{"key":"key2","type":"2"},{"key":"key3","type":"2"}]},{"domain":"e1","units":[{"key":"key11","type":"2"},{"key":"key12","type":"2"},{"key":"key13","type":"2"}]}]}],
units = myjson.reduce(function(p,c) {
return c.files.reduce(function(f,s) {
return f.concat(s.units.map(function(e){
e.domain = s.domain;
return e;
}));
},p);
},[]);
console.log(units);
Something like this should work. .reduce is a good one for these kind of situations.
const allUnits = myjson.reduce((acc, anonObj) => {
const units = anonObj.files.map(fileObj => {
return fileObj.units.map(unit => {
return {...unit, domain: fileObj.domain})
})
return [...acc, ...units]
}, [])
Note that this relies on both array spreading and object spreading, which are ES6 features not supported by every platform.
If you can't use ES6, here is an ES5 implementation. Not as pretty, but does the same thing:
var allUnits = myjson.reduce(function (acc, anonObj) {
const units = anonObj.files.map(function(fileObj) {
// for each fileObject, return an array of processed unit objects
// with domain property added from fileObj
return fileObj.units.map(function(unit) {
return {
key: unit.key,
type: unit.type,
domain: fileObj.domain
}
})
})
// for each file array, add unit objects from that array to accumulator array
return acc.concat(units)
}, [])
Try this
var myjson = [{
"files": [{
"domain": "d",
"units": [{
"key": "key1",
"type": "2"
}, {
"key": "key2",
"type": "2"
}, {
"key": "key3",
"type": "2"
}]
},
{
"domain": "d1",
"units": [{
"key": "key11",
"type": "2"
}, {
"key": "key12",
"type": "2"
}, {
"key": "key13",
"type": "2"
}]
}
]
}];
//first filter out properties exluding units
var result = [];
myjson.forEach(function(obj){
obj.files.forEach(function(obj2){
result = result.concat(obj2.units.map(function(unit){
unit.domain = obj2.domain;
return unit;
}));
});
});
console.log(result);
I am working on a D3.JS chart using an array named "dataset" where each entry is an object with a key and value attributes, such as the following:
dataset=
[
{"key":"alpha", "value": [ {}, { } ...]},
{"key":"beta", "value": [ { }, { } ...]},
{"key":"gamma", "value": [ {}, { } ...]},
{"key":"delta", "value": [ { }, { } ...]}
];
I need to extract one of those objects to create a new array. I have tried the following:
filteredDataset = dataset.filter(function(d){ console.log("d",d); if(d.key === "gamma") return d});
I can see in the console that I am accessing each object in the dataset, but the resulting filteredDataset comes out empty. What am I doing wrong?
For clarity filter should be used by returning a boolean:
Like:
filteredDataset = dataset.filter(function(d){ return d.key === "gamma"})
And on my end the code
var dataset = [
{"key":"alpha", "value": [ {}, { }]},
{"key":"beta", "value": [ { }, { }]},
{"key":"gamma", "value": [ {}, { }]},
{"key":"delta", "value": [ { }, { }]}
];
filteredDataset = dataset.filter(function(d){ return d.key === "gamma"})
Outputs:
[ { key: 'gamma', value: [ {}, {} ] } ]
So please double check your code
dataset.filter(function(d){return d.key === 'gamma';});
This returns the data where key === gamma.
https://github.com/mbostock/d3/wiki/Selections#filter