I am trying to consume a web service in VB6. The service - which I control - currently can return a SOAP/XML message or JSON. I am having a really difficult time figuring out if VB6's SOAP type (version 1) can handle a returned object - as opposed to simple types like string, int, etc. So far I cannot figure out what I need to do to get VB6 to play with returned objects.
So I thought I might serialize the response in the web service as a JSON string. Does a JSON parser exist for VB6?
Check out JSON.org for an up-to-date list (see bottom of main page) of JSON parsers in many different languages. As of the time of this writing, you'll see a link to several different JSON parsers there, but only one is for VB6/VBA (the others are .NET):
The actual syntax for this VB JSON library is really simple:
Dim p As Object
Set p = JSON.parse(strFormattedJSON)
'Print the text of a nested property '
Debug.Print p.Item("AddressClassification").Item("Description")
'Print the text of a property within an array '
Debug.Print p.Item("Candidates")(4).Item("ZipCode")
Building on ozmike solution, which did not work for me (Excel 2013 and IE10). The reason is that I could not call the methods on the exposed JSON object. So its methods are now exposed through functions attached to a DOMElement. Didn't know this is possible (must be that IDispatch-thing), thank you ozmike.
As ozmike stated, no 3rd-party libs, just 30 lines of code.
Option Explicit
Public JSON As Object
Private ie As Object
Public Sub initJson()
Dim html As String
html = "<!DOCTYPE html><head><script>" & _
"Object.prototype.getItem=function( key ) { return this[key] }; " & _
"Object.prototype.setItem=function( key, value ) { this[key]=value }; " & _
"Object.prototype.getKeys=function( dummy ) { keys=[]; for (var key in this) if (typeof(this[key]) !== 'function') keys.push(key); return keys; }; " & _
"window.onload = function() { " & _
"document.body.parse = function(json) { return JSON.parse(json); }; " & _
"document.body.stringify = function(obj, space) { return JSON.stringify(obj, null, space); }" & _
"}" & _
"</script></head><html><body id='JSONElem'></body></html>"
Set ie = CreateObject("InternetExplorer.Application")
With ie
.navigate "about:blank"
Do While .Busy: DoEvents: Loop
Do While .readyState <> 4: DoEvents: Loop
.Visible = False
.document.Write html
.document.Close
End With
' This is the body element, we call it JSON:)
Set JSON = ie.document.getElementById("JSONElem")
End Sub
Public Function closeJSON()
ie.Quit
End Function
The following test constructs a JavaScript Object from scratch, then stringifies it. Then it parses the object back and iterates over its keys.
Sub testJson()
Call initJson
Dim jsObj As Object
Dim jsArray As Object
Debug.Print "Construction JS object ..."
Set jsObj = JSON.Parse("{}")
Call jsObj.setItem("a", 1)
Set jsArray = JSON.Parse("[]")
Call jsArray.setItem(0, 13)
Call jsArray.setItem(1, Math.Sqr(2))
Call jsArray.setItem(2, 15)
Call jsObj.setItem("b", jsArray)
Debug.Print "Object: " & JSON.stringify(jsObj, 4)
Debug.Print "Parsing JS object ..."
Set jsObj = JSON.Parse("{""a"":1,""b"":[13,1.4142135623730951,15]}")
Debug.Print "a: " & jsObj.getItem("a")
Set jsArray = jsObj.getItem("b")
Debug.Print "Length of b: " & jsArray.getItem("length")
Debug.Print "Second element of b: "; jsArray.getItem(1)
Debug.Print "Iterate over all keys ..."
Dim keys As Object
Set keys = jsObj.getKeys("all")
Dim i As Integer
For i = 0 To keys.getItem("length") - 1
Debug.Print keys.getItem(i) & ": " & jsObj.getItem(keys.getItem(i))
Next i
Call closeJSON
End Sub
outputs
Construction JS object ...
Object: {
"a": 1,
"b": [
13,
1.4142135623730951,
15
]
}
Parsing JS object ...
a: 1
Length of b: 3
Second element of b: 1,4142135623731
Iterate over all keys ...
a: 1
b: 13,1.4142135623730951,15
Hopefully this will be a big help to others who keep on coming to this page after searching for "vba json".
I found this page to be very helpful. It provides several Excel-compatible VBA classes that deal with processing data in JSON format.
As Json is nothing but strings so it can easily be handled if we can manipulate it the right way, no matter how complex the structure is. I don't think it is necessary to use any external library or converter to do the trick. Here is an example where I've parsed json data using string manipulation.
Sub GetJsonContent()
Dim http As New XMLHTTP60, itm As Variant
With http
.Open "GET", "http://jsonplaceholder.typicode.com/users", False
.send
itm = Split(.responseText, "id"":")
End With
x = UBound(itm)
For y = 1 To x
Cells(y, 1) = Split(Split(itm(y), "name"": """)(1), """")(0)
Cells(y, 2) = Split(Split(itm(y), "username"": """)(1), """")(0)
Cells(y, 3) = Split(Split(itm(y), "email"": """)(1), """")(0)
Cells(y, 4) = Split(Split(itm(y), "street"": """)(1), """")(0)
Next y
End Sub
VBA-JSON by Tim Hall, MIT licensed and on GitHub. It's another fork of vba-json that emerged end of 2014. Claims to work on Mac Office and Windows 32bit and 64bit.
UPDATE: Found a safer way of parsing JSON than using Eval, this blog post shows the dangers of Eval ... http://exceldevelopmentplatform.blogspot.com/2018/01/vba-parse-json-safer-with-jsonparse-and.html
Late to this party but sorry guys but by far the easiest way is to use Microsoft Script Control. Some sample code which uses VBA.CallByName to drill in
'Tools->References->
'Microsoft Script Control 1.0; {0E59F1D2-1FBE-11D0-8FF2-00A0D10038BC}; C:\Windows\SysWOW64\msscript.ocx
Private Sub TestJSONParsingWithCallByName()
Dim oScriptEngine As ScriptControl
Set oScriptEngine = New ScriptControl
oScriptEngine.Language = "JScript"
Dim sJsonString As String
sJsonString = "{'key1': 'value1' ,'key2': { 'key3': 'value3' } }"
Dim objJSON As Object
Set objJSON = oScriptEngine.Eval("(" + sJsonString + ")")
Debug.Assert VBA.CallByName(objJSON, "key1", VbGet) = "value1"
Debug.Assert VBA.CallByName(VBA.CallByName(objJSON, "key2", VbGet), "key3", VbGet) = "value3"
End Sub
I have actually done a series of Q&As which explore JSON/VBA related topics.
Q2 In Excel VBA on Windows, how to loop through a JSON array parsed?
Q5 In Excel VBA on Windows, for parsed JSON variables what is this JScriptTypeInfo anyway?
VB6 - JsonBag, Another JSON Parser/Generator should also be importable into VBA with little trouble.
Here is a "Native" VB JSON library.
It is possible to use JSON that is already in IE8+. This way your not dependent on a third party library that gets out of date and is untested.
see amedeus' alternative version here
Sub myJSONtest()
Dim oJson As Object
Set oJson = oIE_JSON() ' See below gets IE.JSON object
' using json objects
Debug.Print oJson.parse("{ ""hello"": ""world"" }").hello ' world
Debug.Print oJson.stringify(oJson.parse("{ ""hello"": ""world"" }")) ' {"hello":"world"}
' getting items
Debug.Print oJson.parse("{ ""key1"": ""value1"" }").key1 ' value1
Debug.Print oJson.parse("{ ""key1"": ""value1"" }").itemGet("key1") ' value1
Debug.Print oJson.parse("[ 1234, 4567]").itemGet(1) ' 4567
' change properties
Dim o As Object
Set o = oJson.parse("{ ""key1"": ""value1"" }")
o.propSetStr "key1", "value\""2"
Debug.Print o.itemGet("key1") ' value\"2
Debug.Print oJson.stringify(o) ' {"key1":"value\\\"2"}
o.propSetNum "key1", 123
Debug.Print o.itemGet("key1") ' 123
Debug.Print oJson.stringify(o) ' {"key1":123}
' add properties
o.propSetNum "newkey", 123 ' addkey! JS MAGIC
Debug.Print o.itemGet("newkey") ' 123
Debug.Print oJson.stringify(o) ' {"key1":123,"newkey":123}
' assign JSON 'objects' to properties
Dim o2 As Object
Set o2 = oJson.parse("{ ""object2"": ""object2value"" }")
o.propSetJSON "newkey", oJson.stringify(o2) ' set object
Debug.Print oJson.stringify(o) ' {"key1":123,"newkey":{"object2":"object2value"}}
Debug.Print o.itemGet("newkey").itemGet("object2") ' object2value
' change array items
Set o = oJson.parse("[ 1234, 4567]") '
Debug.Print oJson.stringify(o) ' [1234,4567]
Debug.Print o.itemGet(1)
o.itemSetStr 1, "234"
Debug.Print o.itemGet(1)
Debug.Print oJson.stringify(o) ' [1234,"234"]
o.itemSetNum 1, 234
Debug.Print o.itemGet(1)
Debug.Print oJson.stringify(o) ' [1234,234]
' add array items
o.itemSetNum 5, 234 ' add items! JS Magic
Debug.Print o.itemGet(5) ' 234
Debug.Print oJson.stringify(o) ' [1234,234,null,null,null,234]
' assign JSON object to array item
o.itemSetJSON 3, oJson.stringify(o2) ' assign object
Debug.Print o.itemGet(3) '[object Object]
Debug.Print oJson.stringify(o.itemGet(3)) ' {"object2":"object2value"}
Debug.Print oJson.stringify(o) ' [1234,234,null,{"object2":"object2value"},null,234]
oIE_JSON_Quit ' quit IE, must shut down or the IE sessions remain.
Debug.Print oJson.stringify(o) ' can use after but but IE server will shutdown... soon
End Sub
You can bridge to IE.JSON from VB.
Create a function oIE_JSON
Public g_IE As Object ' global
Public Function oIE_JSON() As Object
' for array access o.itemGet(0) o.itemGet("key1")
JSON_COM_extentions = "" & _
" Object.prototype.itemGet =function( i ) { return this[i] } ; " & _
" Object.prototype.propSetStr =function( prop , val ) { eval('this.' + prop + ' = ""' + protectDoubleQuotes (val) + '""' ) } ; " & _
" Object.prototype.propSetNum =function( prop , val ) { eval('this.' + prop + ' = ' + val + '') } ; " & _
" Object.prototype.propSetJSON =function( prop , val ) { eval('this.' + prop + ' = ' + val + '') } ; " & _
" Object.prototype.itemSetStr =function( prop , val ) { eval('this[' + prop + '] = ""' + protectDoubleQuotes (val) + '""' ) } ; " & _
" Object.prototype.itemSetNum =function( prop , val ) { eval('this[' + prop + '] = ' + val ) } ; " & _
" Object.prototype.itemSetJSON =function( prop , val ) { eval('this[' + prop + '] = ' + val ) } ; " & _
" function protectDoubleQuotes (str) { return str.replace(/\\/g, '\\\\').replace(/""/g,'\\""'); }"
' document.parentwindow.eval dosen't work some versions of ie eg ie10?
IEEvalworkaroundjs = "" & _
" function IEEvalWorkAroundInit () { " & _
" var x=document.getElementById(""myIEEvalWorkAround"");" & _
" x.IEEval= function( s ) { return eval(s) } ; } ;"
g_JS_framework = "" & _
JSON_COM_extentions & _
IEEvalworkaroundjs
' need IE8 and DOC type
g_JS_HTML = "<!DOCTYPE html> " & _
" <script>" & g_JS_framework & _
"</script>" & _
" <body>" & _
"<script id=""myIEEvalWorkAround"" onclick=""IEEvalWorkAroundInit()"" ></script> " & _
" HEllo</body>"
On Error GoTo error_handler
' Create InternetExplorer Object
Set g_IE = CreateObject("InternetExplorer.Application")
With g_IE
.navigate "about:blank"
Do While .Busy: DoEvents: Loop
Do While .ReadyState <> 4: DoEvents: Loop
.Visible = False ' control IE interface window
.Document.Write g_JS_HTML
End With
Set objID = g_IE.Document.getElementById("myIEEvalWorkAround")
objID.Click ' create eval
Dim oJson As Object
'Set oJson = g_IE.Document.parentWindow.Eval("JSON") ' dosen't work some versions of IE
Set oJson = objID.IEEval("JSON")
Set objID = Nothing
Set oIE_JSON = oJson
Exit Function
error_handler:
MsgBox ("Unexpected Error, I'm quitting. " & Err.Description & ". " & Err.Number)
g_IE.Quit
Set g_IE = Nothing
End Function
Public Function oIE_JSON_Quit()
g_IE.Quit
Exit Function
End Function
Up vote if you find useful
You could write an Excel-DNA Add-in in VB.NET. Excel-DNA is a thin library that lets you write XLLs in .NET. This way you get access to the entire .NET universe and can use stuff like http://james.newtonking.com/json - a JSON framework that deserializes JSON in any custom class.
If you are interested, here's a write up of how to build a generic Excel JSON client for Excel using VB.NET:
http://optionexplicitvba.com/2014/05/09/developing-a-json-excel-add-in-with-vb-net/
And here's the link to the code: https://github.com/spreadgit/excel-json-client/blob/master/excel-json-client.dna
I would suggest using a .Net component. You can use .Net components from VB6 via Interop - here's a tutorial. My guess is that .Net components will be more reliable and better supported than anything produced for VB6.
There are components in the Microsoft .Net framework like DataContractJsonSerializer or JavaScriptSerializer. You could also use third party libraries like JSON.NET.
Understand this is an old post, but I recently stumbled upon it while adding web service consumption to an old VB6 app. The accepted answer (VB-JSON) is still valid and appears to work. However, I discovered that Chilkat has been updated to include REST and JSON functionality, making it a one-stop (though paid) tool for me. They even have an online code generator that generates the code to parse pasted JSON data.
Whether you need it for VB6, VBA, VB.NET, C#, Delphi or pretty much any other programming language on the Windows platform, check JSON Essentials. Its capabilities go well beyond just parsing and querying JSON. Using JSON Essentials you can serialize objects into JSON, make JSON HTTP calls and get parsed JSON DOM in response if you need it, re-formatting JSON, using files, registry, memory streams, or HTTP/HTTPS for writing and loading JSON data in UTF-8/16/32 and ASCII/EASCII encodings, and it comes with JSON Schema support. On top of that it's exceptionally fast, stable, standard compliant, being actively developed and supported. And it has a free license too.
Here are some quick samples, the first one shows how to parse and query JSON:
' Create JSON document object.
Dim document As JsonDocument
Set document = New JsonDocument
' Parse JSON.
document.parse "{""a"":true,""b"":123,""c"":{},""d"":[""abc""]}"
' Select the first node of the 'd' node using JSON Pointer
' starting from the root document node.
Dim node_abc As IJsonNode
Set node_abc = document.root.select("/d/0")
' Select node 'a' starting from the previously selected
' first child node of node 'd' and traversing first up to
' the root node and then down to node 'a' using Relative
' JSON Pointer.
Dim node_a As IJsonNode
Set node_a = node_abc.select("rel:2/a")
The next one is about saving/loading a file:
' Load JSON from a UTF-16 file in the current directory
document.load "file://test.json", "utf-16"
' Save document to the current directory using UTF-8 encoding.
document.save "file://test.json", "utf-8"
That's how simple to make an HTTP JSON request using JSON Essentials:
' Load document from HTTP response.
Dim status As IJsonStatus
Set status = document.load("http://postman-echo.com/get")
And that's how to make complex HTTP JSON requests and and parse JSON responses:
' Create and fill a new document model object.
Dim model As SomeDocumentModel
Set model = New SomeDocumentModel
model.a = True
model.b = 123
Set model.c = New EmptyDocumentModel
model.d = Array("abc")
' Load JSON data from a document model object.
document.load model
Dim request As String
' Specify HTTP method explicitly.
request = "json://{" + _
"""method"" : ""PUT"","
' Add custom HTTP query parameters.
request = request + _
"""query"" : {" + _
"""a"" : ""#a""," + _
"""b"" : ""#b""," + _
"""c"" : ""#c""" + _
"},"
' Add custom HTTP form data parameters.
request = request + _
"""form"" : {" + _
"""d"" : ""#d""," + _
"""e"" : ""#e""," + _
"""f"" : ""#f""" + _
"},"
' Add custom HTTP headers.
request = request + _
"""form"" : {" + _
"""a"" : ""#1""," + _
"""b"" : ""#2""," + _
"""c"" : ""#3""" + _
"},"
' Override default TCP timeouts.
request = request + _
"""timeouts"" : {" + _
"""connect"" : 5000," + _
"""resolve"" : 5000," + _
"""send"" : 5000," + _
"""receive"" : 5000" + _
"},"
' Require response JSON document to contains HTTP response status code,
' HTTP response headers and HTTP response body nested as JSON.
request = request + _
"""response"" : {" + _
"""status"" : true," + _
"""headers"" : true," + _
"""body"" : ""json""" + _
"}" + _
"}"
' Save JSON document to the specified endpoint as HTTP PUT request
' that is encoded in UTF-8.
Dim status As IJsonStatus
Set status = document.save("http://postman-echo.com/put", "utf-8", request)
' Print JSON data of the parsed JSON response
Debug.Print status.response.json
And finally here's how to create a JSON Schema and perform JSON document validation:
' Create schema JSON document object.
Dim schemaDoc As JsonDocument
Set schemaDoc = New JsonDocument
' Load JSON schema that requires a node to be an array of numeric values.
schemaDoc.parse _
"{" + _
"""$id"": ""json:numeric_array""," + _
"""type"": ""array""," + _
"""items"": {" + _
"""type"": ""number""" + _
"}" + _
"}"
' Create schema collection and add the schema document to it.
Dim schemas As JsonSchemas
Set schemas = New JsonSchemas
Dim schema As IJsonSchema
Set schema = schemas.Add(schemaDoc, "json:numeric_array")
' Create JSON document object.
Dim instanceDoc As JsonDocument
Set instanceDoc = New JsonDocument
' Load JSON, an array of numeric values that is expected to
' satisfy schema requirements.
instanceDoc.load Array(0, 1, 2)
' Validate JSON instance document against the added schema.
Dim status As IJsonStatus
Set status = schema.validate(instanceDoc)
' Ensure the validation passed successfully.
Debug.Print IIf(status.success, "Validated", "Not-validated")
Using JavaScript features of parsing JSON, on top of ScriptControl, we can create a parser in VBA which will list each and every data point inside the JSON. No matter how nested or complex the data structure is, as long as we provide a valid JSON, this parser will return a complete tree structure.
JavaScript’s Eval, getKeys and getProperty methods provide building blocks for validating and reading JSON.
Coupled with a recursive function in VBA we can iterate through all the keys (up to nth level) in a JSON string. Then using a Tree control (used in this article) or a dictionary or even on a simple worksheet, we can arrange the JSON data as required.
Full VBA Code here.Using JavaScript features of parsing JSON, on top of ScriptControl, we can create a parser in VBA which will list each and every data point inside the JSON. No matter how nested or complex the data structure is, as long as we provide a valid JSON, this parser will return a complete tree structure.
JavaScript’s Eval, getKeys and getProperty methods provide building blocks for validating and reading JSON.
Coupled with a recursive function in VBA we can iterate through all the keys (up to nth level) in a JSON string. Then using a Tree control (used in this article) or a dictionary or even on a simple worksheet, we can arrange the JSON data as required.
Formula in an EXCEL CELL
=JSON2("{mykey:1111, mykey2:{keyinternal1:22.1,keyinternal2:22.2}, mykey3:3333}", "mykey2", "keyinternal2")
DISPLAYS: 22.2
=JSON("{mykey:1111,mykey2:2222,mykey3:3333}", "mykey2")
DISPLAYS: 2222
Tools -> References -> Microsoft Script Control 1.0; {0E59F1D2-1FBE-11D0-8FF2-00A0D10038BC}; C:\Windows\SysWOW64\msscript.ocx
Public Function JSON(sJsonString As String, Key As String) As String
On Error GoTo err_handler
Dim oScriptEngine As ScriptControl
Set oScriptEngine = New ScriptControl
oScriptEngine.Language = "JScript"
Dim objJSON As Object
Set objJSON = oScriptEngine.Eval("(" + sJsonString + ")")
JSON = VBA.CallByName(objJSON, Key, VbGet)
Err_Exit:
Exit Function
err_handler:
JSON = "Error: " & Err.Description
Resume Err_Exit
End Function
Public Function JSON2(sJsonString As String, Key1 As String, Key2 As String) As String
On Error GoTo err_handler
Dim oScriptEngine As ScriptControl
Set oScriptEngine = New ScriptControl
oScriptEngine.Language = "JScript"
Dim objJSON As Object
Set objJSON = oScriptEngine.Eval("(" + sJsonString + ")")
JSON2 = VBA.CallByName(VBA.CallByName(objJSON, Key1, VbGet), Key2, VbGet)
Err_Exit:
Exit Function
err_handler:
JSON2 = "Error: " & Err.Description
Resume Err_Exit
End Function
this is vb6 example code, tested ok,works done
from the above good examples, i made changes and got this good result
it can read keys {} and arrays []
Option Explicit
'in vb6 click "Tools"->"References" then
'check the box "Microsoft Script Control 1.0";
Dim oScriptEngine As New ScriptControl
Dim objJSON As Object
''to use it
Private Sub Command1_Click()
Dim json$
json="{'key1': 'value1' ,'key2': { 'key3': 'value3' } }"
MsgBox JsonGet("key1", json) 'result = value1
json="{'key1': 'value1' ,'key2': { 'key3': 'value3' } }"
MsgBox JsonGet("key2.key3",json ) 'result = value3
json="{'result':[{'Bid':0.00004718,'Ask':0.00004799}]}"
MsgBox JsonGet("result.0.Ask", json) 'result = 0.00004799
json="{key1:1111, key2:{k1: 2222 , k2: 3333}, key3:4444}"
MsgBox JsonGet("key2.k1", json) 'result = 2222
json="{'usd_rur':{'bids':[[1111,2222],[3333,4444]]}}"
MsgBox JsonGet("usd_rur.bids.0.0", json) 'result = 1111
MsgBox JsonGet("usd_rur.bids.0.1", json) 'result = 2222
MsgBox JsonGet("usd_rur.bids.1.0", json) 'result = 3333
MsgBox JsonGet("usd_rur.bids.1.1", json) 'result = 4444
End Sub
Public Function JsonGet(eKey$, eJsonString$, Optional eDlim$ = ".") As String
Dim tmp$()
Static sJsonString$
On Error GoTo err
If Trim(eKey$) = "" Or Trim(eJsonString$) = "" Then Exit Function
If sJsonString <> eJsonString Then
sJsonString = eJsonString
oScriptEngine.Language = "JScript"
Set objJSON = oScriptEngine.Eval("(" + eJsonString + ")")
End If
tmp = Split(eKey, eDlim)
If UBound(tmp) = 0 Then JsonGet = VBA.CallByName(objJSON, eKey, VbGet): Exit Function
Dim i&, o As Object
Set o = objJSON
For i = 0 To UBound(tmp) - 1
Set o = VBA.CallByName(o, tmp(i), VbGet)
Next i
JsonGet = VBA.CallByName(o, tmp(i), VbGet)
Set o = Nothing
err: 'if key not found, result = "" empty string
End Function
Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
Set objJSON = Nothing
Set oScriptEngine = Nothing
End Sub
Here is a new one: [VB6/VBA] JSON parsing to built-in VBA.Collections with JSON Path support
It's a single self-contained module (no classes), parses JSON to nested built-in Collections (fast and lean) and supports practical subset of JSON Path (aka XPath for JSON) to retrieve values.
This means that there is no need to madly nest Item calls like
oJson.Item("first").Item("second").Item("array").Item(0)`
. . . but to access nested values can just use a single call to
JsonValue(oJson, "$.first.second.array[0]")
. . . and retrieve data from as deep in the hierarchy as needed.
