tarun nt
Reputation: 33
how to flatten json file in nodejs using recursion
I have a very complex nested json file and i need to traverse it using recursion
what I need is
- assign the value of innermost value to its parent key
- remove the innermost key and value
- remove empty objects
I have tried many ways and I am new to javascript world and could not come up with the right solution. the json i have is nested as below
{
"Changes_Only": {
"_text": "some value"
},
"Legal_Employee_Id": {},
"EmployeeData": {
"OBJECT_ACTION_ID": {
"_text": "some value"
},
"Employee": {
"PersonID": {
"_text": "some value"
},
"PersonID_OLD": {},
"PersonNumber": {
"_text": "some value"
},
"PersonNumber_OLD": {},
"StartDate": {
"_text": "some value"
},
"StartDate_OLD": {},
"PersonType": {
"_text": "some value"
},
"PersonType_OLD": {},
"DateofBirth": {
"_text": "some value"
},
"DateofBirth_OLD": {},
"HireDate": {
"_text": "some value"
},
"HireDate_OLD": {},
"WorkEmail": {
"_text": "some value"
},
"WorkEmail_OLD": {},
"FirstName": {
"_text": "some value"
},
"FirstName_OLD": {},
"LastName": {
"_text": "some value"
},
"LastName_OLD": {}
},
"NationalIDHT": {
"NtionalIDData": {
"NationalIDValues": {
"NationalType": {
"_text": "some value"
},
"NationalIDNumber": {
"_text": "some value"
}
}
}
},
"AssignmentHT": {
"AssignmentData": {
"Assignment": {
"PersonNumber": {
"_text": "some value"
},
"PersonNumber_OLD": {},
"WorkerNumber": {
"_text": "some value"
},
"WorkerNumber_OLD": {},
"Gender": {
"_text": "some value"
},
"Gender_OLD": {},
"ActionName": {
"_text": "some value"
},
"ActionName_OLD": {},
"HourlySalaried": {
"_text": "some value"
},
"HourlySalaried_OLD": {},
"SalaryBasis": {
"_text": "some value"
},
"SalaryBasis_OLD": {},
"ManagerPersonNumber": {
"_text": "some value"
},
"ManagerPersonNumber_OLD": {},
"ManagerDisplayName": {
"_text": "some value"
},
"ManagerDisplayName_OLD": {},
"AssignmentCategory": {
"_text": "some value"
},
"AssignmentCategory_OLD": {},
"AsgState": {
"_text": "some value"
},
"AsgState_OLD": {},
"JobCode": {
"_text": "some value"
},
"JobCode_OLD": {},
"Desgination": {
"_text": "some value"
},
"Desgination_OLD": {},
"Grade": {
"_text": "some value"
},
"Grade_OLD": {},
"Levele-Grade": {
"_text": "some value"
},
"Levele-Grade_OLD": {},
"Department": {
"_text": "some value"
},
"Department_OLD": {},
"EmployeeType": {
"_text": "some value"
},
"EmployeeType_OLD": {},
"BusinessUnit": {
"_text":"some value"
},
"BusinessUnit_OLD": {},
"BaseLocation": {
"_text":"some value"
},
"BaseLocation_OLD": {},
"PhysicalWorkAddress": {
"_text":"some value"
}
}
}
}
}
}
the json which i need as below also help me remove the empty objects
{
"Changes_Only": "some value",
"EmployeeData": {
"OBJECT_ACTION_ID": "some value",
"Employee": {
"PersonID": "some value",
"PersonNumber": "some value",
"StartDate": "some value",
"PersonType": "some value",
"DateofBirth": "some value",
"HireDate": "some value",
"WorkEmail": "some value",
"FirstName": "some value",
"LastName": "some value"
},
"NationalIDHT": {
"NtionalIDData": {
"NationalIDValues": {
"NationalType": "some value",
"NationalIDNumber": "some value"
}
}
},
"AssignmentHT": {
"AssignmentData": {
"Assignment": {
"PersonNumber": "some value",
"WorkerNumber": "some value",
"Gender": "some value",
"ActionName": "some value",
"HourlySalaried": "some value",
"SalaryBasis": "some value",
"ManagerPersonNumber": "some value",
"ManagerDisplayName": "some value",
"AssignmentCategory": "some value",
"AsgState": "some value",
"JobCode": "some value",
"Desgination": "some value",
"Grade": "some value",
"Levele-Grade": "some value",
"Department": "some value",
"EmployeeType": "some value",
"BusinessUnit": "some value",
"BaseLocation": "some value",
"PhysicalWorkAddress": "some value"
}
}
}
}
}
Upvotes: 0
Views: 155
Answers (3)
vincent
Reputation: 2181
Here is an answer that doesn't rely on string manipulation and uses object-scan.
String manipulation has it's place, but here it could cause issues (i.e. pruning objects that become empty after their properties are pruned). So this answer should be preferred over those using string manipulation
// const objectScan = require('object-scan');
const input = {"Changes_Only":{"_text":"some value"},"Legal_Employee_Id":{},"EmployeeData":{"OBJECT_ACTION_ID":{"_text":"some value"},"Employee":{"PersonID":{"_text":"some value"},"PersonID_OLD":{},"PersonNumber":{"_text":"some value"},"PersonNumber_OLD":{},"StartDate":{"_text":"some value"},"StartDate_OLD":{},"PersonType":{"_text":"some value"},"PersonType_OLD":{},"DateofBirth":{"_text":"some value"},"DateofBirth_OLD":{},"HireDate":{"_text":"some value"},"HireDate_OLD":{},"WorkEmail":{"_text":"some value"},"WorkEmail_OLD":{},"FirstName":{"_text":"some value"},"FirstName_OLD":{},"LastName":{"_text":"some value"},"LastName_OLD":{}},"NationalIDHT":{"NtionalIDData":{"NationalIDValues":{"NationalType":{"_text":"some value"},"NationalIDNumber":{"_text":"some value"}}}},"AssignmentHT":{"AssignmentData":{"Assignment":{"PersonNumber":{"_text":"some value"},"PersonNumber_OLD":{},"WorkerNumber":{"_text":"some value"},"WorkerNumber_OLD":{},"Gender":{"_text":"some value"},"Gender_OLD":{},"ActionName":{"_text":"some value"},"ActionName_OLD":{},"HourlySalaried":{"_text":"some value"},"HourlySalaried_OLD":{},"SalaryBasis":{"_text":"some value"},"SalaryBasis_OLD":{},"ManagerPersonNumber":{"_text":"some value"},"ManagerPersonNumber_OLD":{},"ManagerDisplayName":{"_text":"some value"},"ManagerDisplayName_OLD":{},"AssignmentCategory":{"_text":"some value"},"AssignmentCategory_OLD":{},"AsgState":{"_text":"some value"},"AsgState_OLD":{},"JobCode":{"_text":"some value"},"JobCode_OLD":{},"Desgination":{"_text":"some value"},"Desgination_OLD":{},"Grade":{"_text":"some value"},"Grade_OLD":{},"Levele-Grade":{"_text":"some value"},"Levele-Grade_OLD":{},"Department":{"_text":"some value"},"Department_OLD":{},"EmployeeType":{"_text":"some value"},"EmployeeType_OLD":{},"BusinessUnit":{"_text":"some value"},"BusinessUnit_OLD":{},"BaseLocation":{"_text":"some value"},"BaseLocation_OLD":{},"PhysicalWorkAddress":{"_text":"some value"}}}}}};
const rewrite = (data) => {
objectScan(['**'], {
breakFn: ({ value, gparent, gproperty }) => {
if (typeof value === 'string') {
gparent[gproperty] = value;
}
},
filterFn: ({ value, parent, property }) => {
if (value instanceof Object && Object.keys(value).length === 0) {
delete parent[property];
}
}
})(data);
};
console.log(rewrite(input));
// => undefined
console.log(input);
/* => {
Changes_Only: 'some value',
EmployeeData: {
OBJECT_ACTION_ID: 'some value',
Employee: {
PersonID: 'some value',
PersonNumber: 'some value',
StartDate: 'some value',
PersonType: 'some value',
DateofBirth: 'some value',
HireDate: 'some value',
WorkEmail: 'some value',
FirstName: 'some value',
LastName: 'some value'
},
NationalIDHT: {
NtionalIDData: {
NationalIDValues: {
NationalType: 'some value',
NationalIDNumber: 'some value'
}
}
},
AssignmentHT: {
AssignmentData: {
Assignment: {
PersonNumber: 'some value',
WorkerNumber: 'some value',
Gender: 'some value',
ActionName: 'some value',
HourlySalaried: 'some value',
SalaryBasis: 'some value',
ManagerPersonNumber: 'some value',
ManagerDisplayName: 'some value',
AssignmentCategory: 'some value',
AsgState: 'some value',
JobCode: 'some value',
Desgination: 'some value',
Grade: 'some value',
'Levele-Grade': 'some value',
Department: 'some value',
EmployeeType: 'some value',
BusinessUnit: 'some value',
BaseLocation: 'some value',
PhysicalWorkAddress: 'some value'
}
}
}
}
}
*/.as-console-wrapper {max-height: 100% !important; top: 0}<script src="https://bundle.run/[email protected]"></script>Disclaimer: I'm the author of object-scan
Upvotes: 0
Biswa Soren
Reputation: 325
Try this I am just correcting @Konstantin Pribluda
const r = { ...} // Input JSON
JSON.parse(JSON.stringify(r).replace(/{\s*"_text":\s*("[^"]*")\s*}/g, "$1").replace(/"[^"]*"\s*:\s*{},/g,""))
Second, replace for empty {}
Upvotes: 0
Konstantin Pribluda
Reputation: 12367
Actually you do not need JSON parsing here - you may get away with regex. replacing {"_text": "some value"} with just "some value" will do the trick.
Like this:
str.replace(/{\s*"_text":\s*("[^"]*")\s*}/, "$1")
will take care of
"PersonNumber": { "_text": "some value" },
and
str.replace(/"[^"]*"\s*:\s*{},/,"")
will get rid of empty attributes
Upvotes: 1
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