Reading complex json data as dataframe in R - json

Question

I have the following json data:
json_data <- data.frame(changedContent=c('{"documents":[],"images":[],"profileCommunications":[],"shortListedProfiles":[],"matrimonyUser":{"createdBy":null,"parentMatrimonyUserId":0,"userSalutationVal":"Mr.","matrimonyUserCode":"173773","matrimonyUserName":"SUDIPTO DEB BARMAN","emailAddress":"sudipto06#yahoo.com","contactNumber":"9434944429","emailOTP":"","mobilePhoneOTP":"","isEmailOTPVerified":1,"isMobilePhoneOTPverified":1,"isHideContact":null,"isHideEmail":null,"lastLogInTime":null,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133028,"isDeleted":null,"isActive":1,"isAllowedLogin":null,"numberOfChildProfile":null,"matrimonyUserTypeId":100000006,"matrimonyUserTypeVal":"Online Customer","onlineStatusFlag":null,"lastSystemTransactionDateTime":null,"isLive":null,"mobileCountryCode":0,"userStatusIdValue":"Registered and Verified","crmUserStatusIdValue":null,"deactivateReasonIdValue":null,"deactivateReason":null,"matrimonyUserId":165614,"userSalutationId":100001617,"userStatusId":100002760,"crmUserStatusId":null,"deactivateReasonId":null,"createdOn":null},"aboutMes":[],"partnerPreference":{"isSubcastDealbreaker":null,"isOccupationDealbreaker":null,"isIndustryDealbreaker":null,"isIncomeDealbreaker":null,"isHeightDealbreaker":null,"isBodyTypeDealbreaker":null,"isHivDealbreaker":null,"isFamilyTypeDealbreaker":null,"isFamilyIncomeDealbreaker":null,"isDrinkingDealbreaker":null,"locationTypeIds":null,"isLocationTypeDealbreaker":null,"isLocationNameDealbreaker":null,"locationNameOthers":"","isMaritalStatusDealbreaker":null,"isSmokingDealbreaker":null,"isFoodHabitsDealbreaker":null,"isGothraDealbreaker":null,"isManglikDealbreaker":null,"isProfileCreatedbyDealbreaker":null,"religionIdsValues":"","casteIdsValues":null,"motherTongueIdsValues":"","minimumEducationValues":"","occupationIdsValues":"","industryIdsValues":"","bodyTypeIdsValues":"","hivIdValue":null,"familyTypeIdsValues":"","familyIncomeValues":"","drinkingIdValues":"","locationNameIdsValues":null,"maritalStatusIdsValues":"","smokingIdsValues":"","foodHabitsIdsValues":"","gothraIdsValues":"","manglikIdValue":null,"profileCreatedbyValues":"","heightFrom":null,"heightTo":null,"createdBy":4444,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133115,"isDeleted":null,"isActive":1,"partnerPreferenceId":2757,"isReligionDealbreaker":null,"casteIds":null,"isCasteDealbreaker":null,"isMotherTongueDealbreaker":null,"subcaste":"","religionIds":null,"motherTongueIds":null,"minimumEducation":null,"occupationIds":null,"industryIds":null,"bodyTypeIds":null,"income":null,"incomeValues":"","familyIncome":null,"hivId":0,"familyTypeIds":null,"drinkingId":null,"locationNameIds":"","maritalStatusIds":null,"smokingIds":null,"foodHabitsIds":null,"gothraIds":null,"manglikId":0,"profileCreatedby":null,"adbCount":0,"fifCount":0,"ageFrom":null,"ageTo":null,"isAgeDealbreaker":null,"isminimumEducationDealbreaker":null,"userId":165614,"createdOn":1440167133115,"height":null},"profileAgentDtl":{"campaignId":"","acquirerCode":0,"createdBy":4444,"modifiedBy":4444,"modifiedOn":1440167133110,"isDeleted":null,"isActive":1,"relationshipMangerId":0,"sourceCode":100000004,"userId":165614,"createdOn":1440167133110,"idOdNo":"","relationshipMangerName":null,"relationshipMangerContact":"","profileAgentDtlId":2757,"dateOfEntry":1437935400000,"formSerialNo":"3661","sourceCodeVal":null,"agentCode":null,"acquirerCodeVal":null,"agentName":"","agentMobileNo":"","adBookingNo":""},"profileBasicRegistrationDtl":{"sourceId":null,"createdBy":4444,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133109,"isDeleted":null,"isActive":1,"genderId":100000596,"priorityId":100001671,"profileCreatedById":100000590,"webSourceId":100001672,"dob":null,"genderVal":"Male","userId":165614,"profileCompleteness":null,"createdOn":1440167133109,"profileDtlId":2757,"nickName":null,"relation":null,"regViewersCount":null,"guestViewersCount":null,"trustScore":20,"webSourceVal":"Newspaper ","priorityVal":"Medium","profileCreatedByval":"Self","fieldContentModerationStatusId":null,"photoModerationStatusId":null,"documentModerationStatusId":null,"isPhotoHide":null,"isHoroscopeHide":null},"profileAstrologyDtl":{"createdBy":4444,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133111,"isDeleted":null,"isActive":1,"userId":165614,"createdOn":1440167133111,"profileAstrologyDtlId":2757,"gothraId":0,"gaanId":0,"nakshatraId":0,"sunSignId":0,"moonSignId":0,"manglikFlagId":0,"placeOfBirth":"0","timeOfBirth":null,"isPreferredPartnerDtl":null,"gothraVal":"","gaanVal":"","nakshatraVal":"","sunSignVal":"","moonSignVal":"","manglikFlagVal":""},"profileFamilyDtl":{"permanentAddress":null,"createdBy":4444,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133111,"isDeleted":null,"isActive":1,"familyIncome":0.0,"fathersStatusId":0,"mothersStatusId":0,"fathersOccupationId":0,"mothersOccupationId":0,"mothersIndustryId":null,"fathersIndustryId":null,"familyTypeId":0,"familyValueId":0,"familyKindId":0,"familyStatusId":0,"userId":165614,"createdOn":1440167133111,"moderatedOn":null,"profileFamilyDtlId":2757,"fathersName":"","fathersStatusVal":null,"motherName":"","mothersStatusVal":null,"numberOfSibling":0,"shortRefModerationStatus":null,"fathersOccupationVal":null,"mothersOccupationVal":null,"familyTypeVal":null,"familyValueVal":null,"familyKindVal":null,"familyStatusVal":null,"mothersIndustryVal":null,"fathersIndustryVal":null,"familyIncomeVal":"","moderatedBy":null,"moderatorRemarks":null,"ref1fullName":null,"ref1relationship":null,"ref1emailId":null,"ref1phoneNo":null,"ref1remarks":null,"ref2fullName":null,"ref2relationship":null,"ref2emailId":null,"ref2phoneNo":null,"ref2remarks":null},"profileLifestyleDtl":{"createdBy":4444,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133110,"isDeleted":null,"isActive":1,"favouriteBooksTypeIds":null,"favouriteHobbiesTypeIds":null,"favouriteMoviesTypeIds":null,"favouriteMusicTypeIds":null,"favouriteSportsTypeIds":null,"livingInHouseTypeId":0,"vehicleTypeOwnedId":0,"petsId":0,"drinkingStatusId":0,"numberOfKids":0,"userId":165614,"createdOn":1440167133110,"moderatedOn":null,"moderatedBy":null,"isModerated":null,"moderatorRemarks":null,"profileLifestyleDtlId":2757,"smokingStatusId":0,"foodHabitsId":0,"financialPlansId":0,"retirementPlansId":0,"vehicleDescription":null,"vehicleNumber":0,"childrenDesiredId":null,"isReligionImportantFlagId":null,"religiousBeliefs":0,"smokingStatusVal":"","drinkingStatusVal":null,"foodHabitsVal":"","financialPlansVal":null,"retirementPlansVal":null,"vehicleTypeOwnedVal":null,"livingInHouseTypeVal":null,"petsVal":null,"childrenDesiredVal":null,"favouriteBooksTypeVals":"","favouriteMoviesTypeVals":"","favouriteMusicTypeVals":"","favouriteSportsTypeVals":"","favouriteHobbiesTypeVals":"","isReligionImportantFlagVal":null,"religiousBeliefsVal":"","favouriteHobbiesRating":null,"favouriteHobbiesDescription":null,"noOfKidsVal":null},"profileOccupationEducationDtl":{"highestSpecializationVal":null,"highestSpecializationOthersVal":"","createdBy":4444,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133110,"isDeleted":null,"isActive":1,"highestEducationId":null,"occupationId":null,"designationId":null,"incomeCurrencyId":null,"education2id":0,"education3id":0,"specialization2id":0,"specialization3id":0,"highestSpecializationId":null,"industryId":null,"annualIncome":null,"userId":165614,"createdOn":1440167133110,"moderatedOn":null,"moderatedBy":null,"isModerated":null,"moderatorRemarks":null,"highestEducationVal":null,"occupationVal":null,"industryVal":null,"incomeCurrencyVal":null,"designationVal":null,"education3val":null,"education2val":null,"specialization2val":null,"specialization2othersVal":"","specialization3val":null,"specialization3othersVal":"","additionalQualification":null,"professionalQualification":null,"occupationOthersVal":"","departmentId":null,"employmentSectorId":null,"companyName":"","highestEducationInstituteVal":null,"education2instituteVal":"0","education3instituteVal":"","professionalQualificationVal":null,"departmentVal":null,"employmentSectorVal":null,"annualIncomeVal":null,"profileOccupationEducationDtlId":2757,"schoolName2":"","schoolName1":"","education2instituteId":null,"education3instituteId":null},"profilePersonalDtl":{"createdBy":4444,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133110,"isDeleted":null,"isActive":1,"familyOriginId":0,"stateId":null,"countryId":null,"numChildrenProspect":0,"countryVal":null,"stateVal":null,"landmark":null,"locationVal":null,"userId":165614,"locationId":null,"religionId":100000598,"createdOn":1440167133110,"isPreferredPartnerDtl":null,"maritalStatusId":null,"maritalStatusVal":null,"subCaste":"","profilePersonalDtlId":2757,"motherTongueId":100000618,"casteId":null,"marryOutsideCasteId":0,"familyOriginVal":null,"facebookHandle":"","linkedInHandle":"","twiterHandle":null,"googlePlus":null,"casteText":"Kshatriya","homeTownText":"0","religionVal":"Hindu","motherTongueVal":"Bengali","marryOutsideCasteVal":"","isSocialMediaVerified":null,"numChildrenProspectVal":null,"locality":null},"profilePhysicalAttributesDtl":{"createdBy":4444,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133110,"isDeleted":null,"isActive":1,"hivId":0,"bodyTypeId":0,"complexionId":0,"bloodGroupId":0,"userId":165614,"createdOn":1440167133110,"height":null,"isPreferredPartnerDtl":null,"hairColourId":0,"eyeColourId":0,"hairLengthId":0,"physicalStatusId":null,"disabilitiesVal":"","hivVal":"","knownAilmentVal":"","bodyTypeVal":null,"complexionVal":null,"hairColourVal":"","eyeColourVal":"","hairLengthVal":"","physicalStatusVal":null,"bloodGroupVal":null,"profilePhysicalAttributesDtlId":2757,"weight":null},"profileSiblingsDtl":null,"profileImageDtl":null,"notes":[{"createdBy":4444,"modifiedBy":4444,"modifiedOn":1440167133115,"isDeleted":null,"isActive":1,"userId":165614,"createdOn":1440167133115,"profileNotesDtlId":3499,"notesDescription":""}],"references":[],"relationOthers":[],"photoIdentificationDetails":null,"preModAboutMes":[{"answer":"null ","preModerationAboutMeId":1439283144614540579,"moderationStatus":1,"createdBy":4444,"questionVal":null,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133092,"isActive":1,"isAnswerChange":0,"userId":165614,"questionId":1,"createdOn":1440167133092},{"answer":"null ","preModerationAboutMeId":1439283144614540580,"moderationStatus":1,"createdBy":4444,"questionVal":null,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133093,"isActive":1,"isAnswerChange":0,"userId":165614,"questionId":2,"createdOn":1440167133093},{"answer":"null ","preModerationAboutMeId":1439283144614540581,"moderationStatus":1,"createdBy":4444,"questionVal":null,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133094,"isActive":1,"isAnswerChange":0,"userId":165614,"questionId":3,"createdOn":1440167133094},{"answer":"null ","preModerationAboutMeId":1439283144614540582,"moderationStatus":1,"createdBy":4444,"questionVal":null,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133094,"isActive":1,"isAnswerChange":0,"userId":165614,"questionId":4,"createdOn":1440167133094}],"preModContent":[{"preModerationContentId":1439307323336466240,"isChangeMatrimonyUserName":null,"isChangeLocality":0,"isChangeLandmark":0,"permanentAddress":"Dev Barman,Mayapur,PO-Talbagicha,Kharadpur-721306","isChangePermanentAddress":1,"nameOfInstitutionHighestEducation":"0","highestSpecializationVal":null,"highestSpecializationOthersVal":null,"createdBy":4444,"matrimonyUserName":"SUDIPTO DEB BARMAN","userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133104,"isDeleted":null,"isActive":1,"highestEducationId":0,"occupationId":0,"designationId":0,"incomeCurrencyId":null,"highestSpecializationId":0,"industryId":0,"annualIncome":0.0,"stateId":100000269,"countryId":100000101,"dob":520972200000,"countryVal":null,"stateVal":null,"landmark":"","userId":165614,"moderationStatusId":null,"createdOn":1440167133104,"isChangeNameOfInstitutionHighestEducation":0,"isChangeHighestSpecialization":0,"highestEducationVal":null,"isChangeHighestEducation":0,"occupationVal":null,"isChangeOccupation":0,"industryVal":"","isChangeIndustry":0,"incomeCurrencyVal":null,"isChangeIncomeCurrency":0,"customerTypeId":null,"customerTypeVal":null,"isChangeCustomerType":1,"isChangeDob":1,"maritalStatusId":100000900,"maritalStatusVal":"Never Married","isChangeMaritalStatus":1,"isChangeCountry":1,"isChangeState":1,"cityId":0,"isChangeCity":0,"cityVal":null,"isChangeAnnualIncome":0,"designationVal":null,"isChangeDesignation":0,"subCaste":null,"hometown":null,"isChangeSubCaste":null,"isChangeHometown":null,"ref1fullName":null,"isChangeRef1fullName":null,"ref1relationship":null,"isChangeRef1relationship":null,"ref1emailId":null,"isChangeRef1emailId":null,"ref1phoneNo":null,"isChangeRef1phoneNo":null,"ref1remarks":null,"isChangeRef1remarks":null,"ref2fullName":null,"isChangeRef2fullName":null,"ref2relationship":null,"isChangeRef2relationship":null,"ref2emailId":null,"isChangeRef2emailId":null,"ref2phoneNo":null,"isChangeRef2phoneNo":null,"ref2remarks":null,"isChangeRef2remarks":null,"typeOfCustomer":null,"isChangeTypeOfCustomer":null,"highestEducationInstituteId":null,"typeOfCustomerId":100000006,"locality":""}],"preModReferences":[],"preModShortReferences":[{"moderationStatus":null,"createdBy":4444,"userSessionDtlId":null,"modifiedBy":4444,"modifiedOn":1440167133099,"isDeleted":null,"isActive":1,"userId":165614,"createdOn":1440167133099,"isModerated":null,"premoderationprofileImageDtlId":1772,"ref1fullName":"","isChangeRef1fullName":0,"ref1relationship":"","isChangeRef1relationship":0,"ref1emailId":"","isChangeRef1emailId":0,"ref1phoneNo":null,"isChangeRef1phoneNo":0,"ref1remarks":null,"ref2fullName":"","isChangeRef2fullName":0,"ref2relationship":"","isChangeRef2relationship":0,"ref2emailId":"","isChangeRef2emailId":0,"ref2phoneNo":null,"isChangeRef2phoneNo":0,"ref2remarks":null}],"paymentTransactions":[],"userPlanMappings":[],"userFeatureMappings":[],"userPlanMapping":null,"blockedProfiles":[],"notMyTypeProfiles":[]}')
I want to convert the above to a convenient data frame with 1 row each MatrimonyUserId in the above.I have tried a few things but unable to get this in desired format.

Answer 1

Assuming you can wrangle the json data into a nested list....
x <- jsonlite::fromJSON(jsontext)
I've found it's easiest to parse complex list structures by using the pipe operator and frequently checking the structure (limited to 1 or 2 levels.
str1 <- function(x) str(x, 1)
str2 <- function(x) str(x, 2)
# for pipe operator
library("magittr")
x %>% str1
x %>% .[[1]] %>% str2
Etc.