nfJson

A set of fast performance, reliable and easy to use Json functions using pure VFP.

Project Manager: Marco Plaza

Functions & Usage

( Each function is a single prg - No additional dependencies / Requires VFP9 )

• oJson = nfJsonRead(cJsonString , lReviveCollections)
  Example :
  jsonstr = '{"name":"John", "age":30, "family":{"wife":"Susana","son":"Tom"}, "location":"texas"}'
  vfpobj = nfJsonRead(jsonstr)
  ? vfpobj.age &&will show 30
  ? vfpobj.family.son &&will show Tom

*lReviveCollections: nfJsoncreate stringify key/keyless kcollections as arrays; set this flag if you are parsing json created with nfjsoncreate that you know had a vfp collection; this will perform a extra step to get your collections back from the array representation ( revive it ) or set it to false to view your collections as arrays for debugging purposes -check collectiontest.prg in test folder.

• cJsonString = nfJsonCreate(oVfp, lFormattedOutput, lNoNullArrayItems,cRootName,aMembersFlag)

• nfJsonToCursor(cJson, cCursorName , lForceImportFromArray) ( creates cursor back from Json created using nfCursorToJson4vfp, for any other case see nfOpenJson and notes below: )

• cJsonString = nfCursorToJson4vfp() && converts current open table/cursor to Json suitable for later use of nfJsonToCursor()

• cJsonString = nfCursorToJson(lReturnArray, lArrayofValues, lIncludestruct, lFormattedOutput) converts current open table/cursor to Json

• oJson = nfCursorToObject(lCopyToArray, lIncludeStruct)

• cJsonString = jsonFormat( cJsonStr )* Format json string w/o validate or change element positions

• nfOpenJson(** cJsonString , [ cArrayPath ], [cCursorStructure & object mappings ] )

  Similar to SqlServer 2016 openJson function

To convert json to cursor:

For simple 1:1 conversion I recommend to simply use nfJsonRead and a existing destination cursor like this:

TEXT to mssample2 noshow
[
{ "CorpCode": "KAKK01",
"MobNo": "9447820950",
"KitID": "2320007005",
"EwireTxnNo": "2"
},
{ "CorpCode": "KAKK01",
"MobNo": "9544727140",
"KitID": "2320007006",
"EwireTxnNo": "2"
}
]
ENDTEXT

ox = nfJsonRead(m.mssample2)
Create Cursor temp ( corpcode v(10), mobno v(20),kitid v(10), ewireTxnNo v(10) )

For Each Row In ox.Array
	Insert Into temp From Name Row
Endfor

BROWSE TITLE 'using nfJsonRead'

** Use nfOpenJson to flatten objects with ease ( check a discussion here https://www.tek-tips.com/viewthread.cfm?qid=1796615 )

*** using nfOpenJson:

TEXT to mssample3 noshow
[
{ "CorpCode": "KAKK01",
"MobNo": "9447820950",
"KitID": "2320007005",
"EwireTxnNo": "2",
"person":{"name":"Curt","age":54,"phone":["12345","5645466"]}
},
{ "CorpCode": "KAKK01",
"MobNo": "9544727140",
"KitID": "2320007006",
"EwireTxnNo": "2",
"person":{"name":"David","age":55,"phone":["142145","4665465"]}
}
]
ENDTEXT

TEXT TO curstruc NOSHOW TEXTMERGE PRETEXT 8
- corpcode v(10) $.corpCode
- mobno v(20) $.mobNo
- kitid v(10) $.kitid
- ewireTxnNo v(10) $.ewireTxnNo
- name v(10) $.person.Name
- age i $.person.age
- phone1 v(10) $.person.phone[1]
- phone2 v(10) $.person.phone[2]
ENDTEXT

nfOpenJson( m.mssample3,'array',m.curstruc)

BROWSE TITLE 'Using nfOpenJson'

Tests & Sample files

• nfOpenJsonTest: samples taken from https://docs.microsoft.com/en-us/sql/t-sql/functions/openjson-transact-sql

• nfJsonPerfTest.prg: just run it and choose one of the embedded json samples from the list to check performance on your pc. ( Allows you to parse Json from clipboard too. )

• examples.prg will parse the next Json files included in JsonSamples folder. just run from test folder and see sample code and output.

• collectionTest.prg: creates a complex collection , converts it to Json and back to vfp.

• Sample Json files included:

  • youtubesearch.json
  • cycloneForecast.json
  • dropbox.json
  • googleMapsDistance.json
  • iphone photo.json
  • mapquest.json
  • mySimpleArray.json
  • tweeter.json
  • weatherService.json
  • yahooweather.json

Release Notes

2022/07/09 ( PatrickvonDeetzen )

• create json with special characters is now significantly faster (changes made in function "escapeandencode")
• updated performance test & added new test sample
• bug fix: missing m. in nfcursortoobject.prg

2019/06/14

• JsonFormat function by Carlos Alloati

2017/08/05

• no matter wich strictdate setting you have set, a JsonDateTime "0000-00-00T00:00:00" will return an empty date.
• valid JsonDates with time "T00:00:00" will return a date value ( ie: {"testDate":"2017-12-01T00:00:00"} )
• invalid dates ( ie 2017/50/50 ) properly formatted as Json Date ( ie: 2017-50-50T00:00:00 ) will throw error; ( previous behavior was to return .null. )

2017/03/10

• fixed: proper support for 19 character strings with ISO basic date format & different strictdate settings.

2017/02/05

• fixed: nfJsonRead bug fix: incorrect parsing for strings terminated with escaped double quotes; minor changes & code refactoring.

2017/01/11

• fixed: nfJsonRead: incorrect unescaped output with "set exact = on"
• escapetest.prg - removed "leftover" lines.

2017/01/11

• fixed issue escaping values terminated with "
• nfJsonRead: removed parameter "isFile" now you can just pass a file name or string
• added test: escapeTest.prg

2016/09/28

• minor bug fix: zero item collections created as 1 empty item collection
• proper indent for raw/formatted collection objects

2016/08/16

• nfJsonPerfTest: added compiled exe, samples file ships as a separate file for you to edit
• fixed bug on test prgs: clean installs would fail due to missing temp folder on distribution zip w/o tests\temp folder
• fixed bug on collectionTest

2016/07/22

• nfJsonRead: Improved error management
• CollectionTest: added new test

2016/07/20

• Fixed bug: missing closing curly brace on collections as object member
• Updated collections program test

2016/07/09

• Automatic cast for datetime properties ( ISO-8601 basic format & vfp compilant as described on https://en.wikipedia.org/wiki/ISO_8601#Times. )
• nfJsonToCursor Bug Fix: "Date/datetime evaluated to an invalid value" while running under "strictdate = 1" converting empty dates back from Json

2016/07/04

• Added support for control characters encoding ( chr( 0) ~ chr(31) )

2016/05/05

• invalid Json error shows calling program information

2016/04/02

• complex nested objects/arrays validation
• missing object/array closures validation

2016/03/28

• nfJsonRead performs JSON validation: invalid Json throws error indicating reason.
• nfJsonPerfTest: proper error management enabled for invalid Json input from clipboard
• nfJsonToCursor: use of strict date format