Have already incorporated JsonBag2.4 into my own projects. So far it works perfectly well.
The documentation is very good.
Will come back and report bugs, if any. ;)
Printable View
Have already incorporated JsonBag2.4 into my own projects. So far it works perfectly well.
The documentation is very good.
Will come back and report bugs, if any. ;)
An update to the JsonDate.cls companion class. Breaking changes, so read the "Changes" text file. Now version 2.0 but no new JsonBag.cls here.
Handles Unix timetamp values in both seconds and milliseconds. Corrects conversions to/from local time to handle DST better. This means it won't work on Windows XP and earlier dead versions of Windows... but see the comments for "fallback" code you can use if you need XP support as well.
ISS Plot Demo
This demo makes use of the super simple "Where the ISS at?" REST API web service to plot the position of the International Space Station over the Earth against a simple "equirectangular projection" map.
Much of the size of the attachment is images.
The program uses JsonBag 2.4 and JsonDate 2.0 along with WinHTTP to make a position request every 5 seconds. Since this is a free web service that doesn't even require a free account, anyone should be able to unzip and run the demo on Windows Vista SP1 or later.
With tweaks mentioned above to JsonDate.cls it should even run on Windows XP.
It's a quick and dirty demo, so there might be some errors in the offsets and arithmetic used to position the IIS icon and "drop" the red trail of breadcrumbs. But it works well enough for demo purposes.
If you are interested in this sort of thing, the API might be expanded in the future to track more orbital objects as well as the ISS. There are other similar web services from other sources for more data regarding orbiting stuff and astronomy more generally.
JsonBag 2.5:
No logic changes of any significance. Just a change to several properties that accepted an "Optional ByVal Arg As Variant = Null" argument.
If you have any of these your Class cannot be compiled into a VB6 DLL, OCX, etc. This involves a subtle point of COM Marshalling.
The fix is to remove the default Null value and early in the procedure test for IsMissing() and if True assign Null to the Optional argument. The result should compile and work identically to the original.
Thanks to engowen for bringing this up. Thanks to VB and C# Watcha's, Gotcha's, Tips & Tricks for the solution.
Hello,
I have installed (Excel Demo (2.4) ) and with sample works as expected
I am trying to figure out how to use another JSON data file (prefer to get by WinHttp method)
I have read through the documentation but can not figure out how to get to array that have objects and then strings.
the sample file lib.json (lib.txt) Attachment 142049
How would I get "issuelinks" (an array) and then create headers from the objects "id" ,"self","type" : object+{"id","name","inward" ,"outward" "self}..., etc and then populate rows. Maybe to complex JSON?
This json can be retrieved from: https://jira.atlassian.com/rest/api/2/issue/JRA-9.json
I am using VBA and tried VBA-JSON but can't get it to work.
I am sorry that I don't understand how this works, any help would be appreciated.
I am using VBA and tried VBA-JSON but can't get it to work.
I am trying to parse a JSON file and am getting an error at this step:
Private Sub SkipWhitespace(ByRef Text As String)
CursorIn = CursorIn + StrSpn(StrPtr(Text) + 2 * (CursorIn - 1), PtrWhiteSpace)
End Sub
Compile error: type mismatch
Using VBA and Jsonbag 2.1
VBA support isn't thoroughly tested, especially in a 64-bit VBA host. I suggest you try a newer version though, there were some VBA-related changes made in version 2.4 that might address this.Quote:
Originally Posted by mjk1165
I have updated to version 2.5. The JSON function seems to works and return the information but I am not able to access the data.
in the Locals window I see:
myJB
...
Names
...
Values
...
Item 1
Item 2
...
the .item() functiont returns, "key not found"
the .itemJOSN() functions gives compile error "type mismatch"
I have not sure I have the right syntax:
Date from I
I have updated to version 2.5. The JSON function seems to works and return the information but I am not able to access the data.
in the Locals window I see:
myJB
...
Names
...
Values
...
Item 1
Item 2
...
the .item() functiont returns, "key not found"
the .itemJOSN() functions gives compile error "type mismatch"
I have not sure I have the right syntax:
Date from I
Perhaps this might help?
sample.js
Code:{"sample":
{ "fudge": "vanilla",
"story":
{ "title": "Konfabulator Magnifico",
"author": "Fred G. Poobles",
"pages": 53,
"words": 12000
},
"text":
[ "Click Here",
"Bold",
"Fresh"
]
}
}
Code:Dim JB As JsonBag
Dim F As Integer
Dim I As Integer
Dim JBText As JsonBag
Set JB = New JsonBag
F = FreeFile(0)
Open "sample.js" For Input As #F
JB.JSON = Input$(LOF(F), #F)
Close #F
Print " Single sample:fudge:"
Print , JB.Item("sample").Item("fudge")
Print " Single sample:story:title:"
Print , JB.Item("sample").Item("story").Item("title")
Print " List sample:story:"
With JB.Item("sample").Item("story")
For I = 1 To .Count
Print , .Item(I)
Next
End With
Print " Single sample:text(1):"
Print , JB.Item("sample").Item("text")(1)
Set JBText = JB.Item("sample").Item("text")
Print " List JBText:"
For I = 1 To JBText.Count
Print , JBText.Item(I)
Next
Attachment 143933
I have made progress with reading the jsonbag.
The function fails still when retriving some keys, with a error 3265 - 'Item not found in Collection'. What is odd is the that when I a follow the code, it seems to find the key and retrieve the value, but falls out of the 'Property Get' function with the 'Item not found... error or Run-time -424 - Object Required. The key is 'message' which appears to be a nested json, but I have another routine where it fails on string values.
I included a link to the file I am trying to parse.
https://www.dropbox.com/s/b91uhc8lfr...Logs.json?dl=0
I appreciate any direction you could provide.
Mike
I'm not seeing a problem. I had no trouble parsing and using your sample document.
Attachment 144139
Your sample JSON is in the attachment.Code:Option Explicit
Private Sub Form_Load()
Dim JB As JsonBag
Dim F As Integer
Dim JBLogs As JsonBag
Dim LogName As String
Dim JBLog As JsonBag
Dim Row As Long
Dim Col As Long
Dim JBMessage As JsonBag
Set JB = New JsonBag
F = FreeFile(0)
Open "SD_Logs.json" For Input As #F
JB.JSON = Input$(LOF(F), #F)
Close #F
'Discard all but "logs" from here on:
Set JBLogs = JB.Item("logs")
Set JB = Nothing
Caption = "Dump of SD_Logs.json ""logs"""
With MSHFlexGrid1
.WordWrap = True
.ColWidth(0) = TextWidth("..log..")
.Rows = JBLogs.Count + 1
Set JBLog = JBLogs.Item(1)
.Cols = JBLog.Count + 1
.Row = 0
.Col = 0
.Text = "log"
For Col = 1 To .Cols - 1
.Col = Col
.Text = JBLog.Name(Col)
.ColAlignment(Col) = flexAlignLeftTop
Next
'JBLog item 4 is the very long embedded JSON "message" value:
.ColWordWrapOption(4) = flexWordBreakEllipsis
.ColWidth(4) = 4320
Set JBMessage = New JsonBag
For Row = 1 To .Rows - 1
.Row = Row
If Row > 1 Then Set JBLog = JBLogs.Item(Row)
.Col = 0
.Text = JBLogs.Name(Row)
For Col = 1 To .Cols - 1
.Col = Col
If Col = 4 Then
'Parse the embedded JSON and extract the first "error" value:
JBMessage.JSON = JBLog.Item(Col)
.Text = JBMessage.Item("errors").Item(1)
Else
.Text = CStr(JBLog.Item(Col))
End If
Next
.RowHeight(Row) = TextHeight("Wjgy") * 4
Next
End With
End Sub
Private Sub Form_Resize()
If WindowState <> vbMinimized Then
MSHFlexGrid1.Move 0, 0, ScaleWidth, ScaleHeight
End If
End Sub
Turns out that:
... wasn't used above. I was coding on the fly so I declared something I didn't use. Just ignore it but I didn't want to add confusion.Code:Dim LogName As String
Just tested your last example, and you might want to fix your "parsing-handler for numeric data" -
in the last column you convert the (quite large) integer into a double, which could lead to imprecise output or calculations
(in the RichClient I start with mapping Integer-Numbers to Longs I think, then Currencies, and then Decimals, in case
the incoming Numbers "cross" the "fitting-boundaries" of the types in question).
The Field(Values) I mean (which are mapped to a Double-Type), are the last ones in the records of the larger JSON-array:
..., "_version_":1556427511093526531}
Olaf
That's a funny edge case.
The JSON spec allows integers (Number) of unlimited size, but Javascript itself treats integers that large the same as a "Double".
What do you do when it doesn't fit in a Decimal? keep it a string?
As it says in the documention (not included in the example above but in the other uploads before it):
So most JSON parsers deal with it one way or another, and that's how JsonBag does it. The default is Double which is what the spec calls for even though that is widely violated. JSON inherits the weak type system of JavaScript.Quote:
DecimalMode As Boolean [read/write]
Defaults to False.
The setting of this property determines how numbers are parsed and serialized. See the discussion Impact Of DecimalMode Setting above.
This should only be set on a JsonBag instance that is being used as a "root" document node when it is empty.
Slopping a "number" into an Integer for example can lead to unexpected overflows when somebody works with it. That's one of the reasons why trying to get clever can blow up in users' faces. Badly.
But you have to make a decision one way or the other, and that's just how the JSON game goes.
It was just a hint, to not leave anything to chance (or to some Usage-Properties, which might not be switched away from their defaults)...Quote:
Originally Posted by dilettante
In my understanding, the usage of Doubles (IEEE754) is just a suggestion (since it's a commonly available type between languages).
But VB6 *does* have support for higher precision (per Decimal-Variants) - so why not switch *automatically* to
the Dec-Types (in the Variant-holding Collection), when e.g. a large Int64 value comes along (often used in DB-Tables as Record-ID)
To detect, whether the text-representation of a number is an integer, is a no-brainer -
it can be easily determined at the parsing-stage, by checking for the local-invariant: "."
Sure, JavaScript cannot deal with the large Integer-Value (as shown in post #73),
and for example, when it's meant as an ID (e.g. to identify a Record in a DB-Table)...:
alert( JSON.stringify( JSON.parse('{"ID":1556427511093526531}') ) );
... will give the serialized output: {"ID":1556427511093526500} - which is a loss of information,
... so a potential next roundtrip back to the WebServer (and its DB) will cause errors due to not matching IDs
(e.g. when the purpose is an Update-Query, to store some piggy-back-traveling extra-JSON-fields under that ID).
Though many other languages (and JSON-Parsers) will not have any problem with such a large Integer-Value (VB6 among them) -
in the meantime JSON is not a "JavaScript-only"-thing anymore - it's a quite wide-spread serialization-format -
and the usage of RPCs is not limited to (WebBrowser+JavaScript)<->(WebServer) communication.
Just my 0.02$... <shrug>
Olaf
Thank you for all your help. My biggest challenge is my lack of experience with JSON's.
I am working my way thru each nested JSON using your example. Is there way to tell if a key exists in a JSON? For example, the message block could have messages warnings or errors, and I would want to handle the information differently.
As it says in the JsonBag.rtf document:
Quote:
Exists(ByVal Key As Variant) As Boolean
Only meaningful on "Object" JsonBags. Used to determine whether a named Item exists, by name or index.
"Array" type JsonBag list members indices always range from one (1) to Count.
The way Javascript and PHP deals with overly large integers - is to export them as a JSON strings.
I remember this being a fiasco when facebook went to 64bit IDs, and broke a bunch of APIs.
The best thing about this class - is it's open source. We can modify it to suit specific needs, and edge case behavior.
Yep, and that raises the question, which toolset (or language) did produce the JSON-serializationQuote:
Originally Posted by DEXWERX
(containing that large Integer-Value in mjk1165's example)...
Apparently it expects a JSON-parser (on the other end), which is capable to understand
(and not mangle) that Integer-Value.
Well, I hope mjk1165 is capable of doing that...Quote:
Originally Posted by DEXWERX
As it is currently, I hope he understood from what was said, that he has to use a specific non-default-setting on diles JSON-Bag,
to not run into issues with that Integer (e.g. on a potential back-posting roundtrip with "re-serialized" content to the ServerSide).
The "automatic-fallback-mode to Decimal" I was suggesting (when Integer-Numbers get too large) would hurt nobody
(even in the Default-Setting "Parse-Numbers-into-Doubles") and would require the least efforts, when dile does it himself.
But as said, it was only a well-meant suggestion (take it or leave it)...
Olaf
I'm not arguing with you - It's definitely a good suggestion.Quote:
Originally Posted by Schmidt
The JsonBag has a property for this, just as documented (unlike so much undocumented closed-source code of dubious attribution people promote):
It is a trivial matter to assign True to this property or even to alter its default value to True. The latter is spelled out pretty explicitly:Quote:
DecimalMode As Boolean [read/write]
Defaults to False.
The setting of this property determines how numbers are parsed and serialized. See the discussion Impact Of DecimalMode Setting above.
This should only be set on a JsonBag instance that is being used as a "root" document node when it is empty.
If somebody can't figure out how to change the default value to True they have a bigger problem. ;)Code:Private Sub Class_Initialize()
TypeNameOfMe = TypeName(Me)
PtrWhiteSpace = StrPtr(WHITE_SPACE)
Clear 'Creates Collections.
DecimalMode = False 'Default
Whitespace = False 'Default
WhitespaceIndent = 4 'Default.
WhitespaceNewLine = vbNewLine 'Default.
End Sub
You're repeating yourself.Quote:
Originally Posted by dilettante
My point was, that this property would be completely unnecessary (with just a slight addition in your parsing-code).
As it is, it is just confusing - especially since it behaves inconsistently (and is *not* adhering to your "documentation").
Since you say in your Doc: "...this property determines how numbers are parsed and serialized..."
Example:
So - the latter result (of JB2 above) is not holding its promise (to serialize in Double-Format, as the Doc states),Code:Dim JB1 As New JsonBag
JB1.DecimalMode = False '<- use Double-Mode
JB1.JSON = "{""longNumber"":1556427511093526531}"
Debug.Print JB1("longNumber") 'will print 1.55642751109353E+18
Dim JB2 As New JsonBag
JB2.DecimalMode = False '<- use Double-Mode
JB2("longNumber") = CDec("1556427511093526531")
Debug.Print JB2.JSON 'will print {"longNumber":1556427511093526531}
since a Double clearly cannot hold an integer-value in that precision (as the first printout of JB1 shows).
So, as already suggested - either fix your code - or your wrong documentation
(now curious whether you're able to manage one of the two things without further sidekicks,
a simple "dear fellow-developer, thank you for pointing that out" would already be enough... <g>).
Olaf
Perhaps you didn't read the documentation?
Under the discussion on DecimalMode it says:
The behavior you showed above matches this exactly. If anything perhaps there is a small flaw there (the bold text you quoted), but unlike some people I provide both the source and documentation. I'll keep this documentation change in mind for a future release. At least it has been covered to death here now though.Quote:
This property setting only impacts assignments to the JSON property, i.e. parsing serialized JSON. If you directly assign a numeric value the actual type your code used is stored in the object hierarchy data. Of course as noted it may also impact retrieval from the JSON property, i.e. serializing the tree into JSON text.
Let's cut back on the sniping shall we... in both directions. You've both provided some excellent work in this forum and both deserve to have that acknowledged.
keep any criticism friendly and constructive and let's receive it in the same vein.
Hey guys,
i' on was on the version 1,6, it was working perfectly, thanks for great job.
But :) One week ago our IT updatet the Office 2010 to 64 bit and it didn't work
Ok, i updatet the JsonBag to version 2,5 and now i have the problem with "Names"
"Set ContractNames = JsRoot.Item(x1).Item("rows").Item(x2).Item("data").Names"
unfortunately after set the object is always ContractNames = nothing
Can you help me please?
json is attached
Hey guys!
our it updated the office to the 64 bit version, so i updated jsonbag to the 2.5 version and now i have a problem with the "names"
Set ContractNames = JsRoot.Item(x1).Item("rows").Item(x2).Item("data").Names
after set is the object ContractNames = nothing
can you tell me, what i am doing wrong? thanks in advance
PS: json is attached
PSS: sorry for my bad english
PSSS: Dim ContractNames As CollectionQuote:
Originally Posted by paul-ac
Names will never return a Collection. The value will either be a simple value type or else a JsonBag instance.
We have no way to guess what your "x1" variable is or what value it has. That makes it very difficult to explore for possible problems.
The Json text in your attachment seems to parse just fine in JsonBag.
I see nothing here to suggest that moving to 64-bit VBA makes any difference. Are you sure this ever worked before in 32-bit VBA?
Yes, it worked for me.Quote:
Originally Posted by dilettante
Now i changed the code and it works, thanks !
Hi there,
I'm trying to parse Json data but without any luck with v1.8 on Windows 7 64-bit:
I'm unable to get any readings by:Code:{
"ESP8266": {
"NTC": {
"temperature": 18.03633
},
"DHT11": {
"temperature": 19,
"humidity": 59
},
"SHT30": {
"temperature": 19.48043,
"humidity": 63.17846
},
"BMP180": {
"temperature": 19.7,
"pressure": 997.52
},
"WU": {
"temperature": 1.6,
"humidity": 98,
"pressure": 1006
}
}
}
Also got some error saying:Code:Debug.Print objJson.Item("ESP8266").Item("NTC").Item("temperature")
But, if I check the feeded JSON Object, it's clear reading.Code:Requested Item by key doesn't exist (case mismatch?)
Code:Debug.Print objJson.JSON
So, I don't know what I'm doing wrong.Code:{"ESP8266":{"NTC":{"temperature":18.03633},"DHT11":{"temperature":19,"humidity":58},"SHT30":{"temperature":19.73144,"humidity":62.63981},"BMP180":{"temperature":20.1,"pressure":997.25},"WU":{"temperature":1.6,"humidity":97,"pressure":1006}}}
Please advise!
Kind regards,
Viktor
Anyway, after one and a half day strugling, I figured out that I was destroying the Json Object on the half way! :D
I use the JsonBag 2.5
and this code works perfect for me
Code:Dim J As New JsonBag
J.JSON = Text1.Text
Debug.Print J.Item("ESP8266").Item("NTC").Item("temperature")
As I wrote before, I forgot to removeQuote:
Originally Posted by yokesee
and the JSON Object was empty alwaysHTML Code:Set objJson = Nothing
Hi there,
Why I'm getting this from the Jeson parser:
when I'm feeding with these values:Code:{
"ESP8266": {
"NTC": {
"temperature": 18.65
},
"DHT11": {
"temperature": 21,
"humidity": 48
},
"SHT30": {
"temperature": 21.59,
"humidity": 56.03
},
"BMP180": {
"temperature": 22.1,
"pressure": 999.06
},
"WU": {
"temperature": 8.6,
"humidity": 77,
"pressure": 1006
}
}
}
So, where are my decimals gone?Code:{
"ESP8266": {
"NTC": {
"temperature": 18.65
},
"DHT11": {
"temperature": 21.00,
"humidity": 48.00
},
"SHT30": {
"temperature": 21.59,
"humidity": 56.03
},
"BMP180": {
"temperature": 22.10,
"pressure": 999.06
},
"WU": {
"temperature": 8.60,
"humidity": 77.00,
"pressure": 1006.00
}
}
}
Kind regards,
Viktor
They are gone because they're supposed to be gone. That isn't from the parser but the serializer.
JSON has just a simple "number" type for numeric values. On decoding these become Double (or optionally Decimal). Don't be confused about the text representation once re-encoded back to JSON. JSONBag serializes numeric values back to a compact form, desirable to keep transmission costs down.
Nothing in the JSON spec requires retaining the original formatting of a value within the parsed JSON text. Even if it did, there are no rules to tell you how to format the value if changed or a new value is added, etc. JSON makes no provision for formatting numeric values any particular way as long as they result in a legal JSON "number."
If you really, really wanted this for some odd reason you would have to add another property to each numeric JSONBag item for "format" though I have no idea how reliable the parser could be at deciding what "format string" to assign when values are parsed.
dilettante, thank you.
This parser is very very necessary thing for a modern format of settings storage.
dilettante:
FWIW:
Just ran your JSON 2.5 Firefox bookmarks.
Stuck in loop and had to use Ctrl-Alt_Delete to exit.
For further discussion see here:
http://www.vbforums.com/showthread.p...lete-Bookmarks
Sounds like you have found a bug. Can you provide sample data that reproduces the problem?
If you break execution in the IDE what line is it on?
dilettante:
Happy New Year. Decided to come off my break early so in response to your questions:
Running your Demo2 from Version 2.5, with my bookmarks.json file.Quote:
If you break execution in the IDE what line is it on?
Everytime I break it end up in Form1:Proc: "DumpText"
At break bookmarks.json values are valid as I search bookmarks file to verify.
Just seems to repeat -- stuck in loop.
This is a tough one as using a copy of my actual bookmarks file.Quote:
Can you provide sample data that reproduces the problem?
See what I can do.
You can try make regexp-replacements of personal data.
As soon as this line of code finishes:
... the parsing is done. So the problem is probably not in JsonBag at all.Code:JB.JSON = JsonData
The rest of that program (mainly JbDump) just tries to walk the JsonBag tree and dump everything.
After that it queries a couple of items and displays than in MsgBox dialogs, but you probably deleted that part since it was specific to the original sample JSON document.
If JbDump has a problem I don't see it. Did you alter it? When you break try View|Call Stack... to walk back and find out where DumpText was called from. What are the values of Name, Level, JB.Count, and ItemIndex?
Without a sample file that produces this problem there isn't a lot we can do remotely.
Dragokas:
Have never worked with regexp so a non-starter.Quote:
You can try make regexp-replacements of personal data.
Was looking at a possible Search / Replace but Not sure amount effort involved.
I would think any Firefox bookmark file would give the same problems as IMHO it is more in their JSON format than in my data.
dilettante
Give me a couple days to see what I can come up with.
If my data agree, if Firefox bookmark format is issue then any Firefox JSON bookmark file should give same error. Firefox appears to use arrays of objects (children) which may be nested fairly deep.Quote:
Without a sample file that produces this problem there isn't a lot we can do remotely.
Quick Followup:
No, other than to substitute path to bookmarks.json which I copied to same directory as the program.Quote:
Did you alter it?
Did three different breaks and followed Call Stack each time to JbDumpQuote:
When you break try View|Call Stack... to walk back and find out where DumpText was called from. What are the values of Name, Level, JB.Count, and ItemIndex?
Checked the values for the variables suggested at each break.
All variables at EACH break had different values, but values look good -- from my bookmarks.json file.
=================
When I run Demo2 using the bookmarks.json file the left side "RTB" is stable and appears to show the bookmarks.json file (source) correctly from a cursory review. the right side "RTB" is the one that scrolls continuously as if stuck in a loop.
==================
After the 3 breaks ran again until appeared locked.
Quote:
IGNORE THE FOLLOWING - POSTED IN ERROR because:
Since I broke on JbTest I would expect JbDump to have "Subscript out of Range" errors
and other variables to be questionable
==================================================
In checking JbDump the key issue appears to be "Subscript out of Range"
The other variables had values of:Code:<< This following line and any other line with JB.Item(ItemIndex)
<< in JbDump shows as "Subscript out of Range"
If TypeOf JB.Item(ItemIndex) Is JsonBag Then
Name = ""
ItemIndex = 0
JB.Count = 8
What if you add two lines to remove the overhead of the control's UI updating?
Code:Set JB = New JsonBag
JB.JSON = JsonData
Show
txtJsonBagDump.Visible = False
JbDump "*anonymous outer JsonBag*", JB
txtJsonBagDump.Visible = True
HomeDump
Thanks for the code and suggestion.
Sadly, let run for 10 minutes and no output in Right Textbox.
This weekend will try and debug and see if I can pinpoint where hangup is occurring.
FWIW: Dumped just the first few lines of the file and grouped them (blank lines between groups)
to get some idea of the format.
Lot of embedding.
Hi, Wonder if anyone can help.
I am using jsonbag and works very well. However, i send a query to a website and expect to get a list of stuff back.
This all works good. However if i send an incorrect code i get a json respone that gives me
P.Item("name") = "Not Found"
If when i check P.Item("name") = "Not Found" everything works and i exit the sub , but when i send a valid query and
everything is ok i get P.Item(Row).Item("xxxxxxx")
How do i check the error raised when P.Item("name") is not even returned.
I am using VB6 and get Runtime error 5 . invalid call or procedure.
i have tried checking Not IsNull(P.Item("name")) and some other variations but the only way i can
see is to use Goto err handler which i did not want to do.
Is there a way to catch this error of an item not being avail.
many thanks
Try turning the circled option on in the IDE:
Attachment 155289
Nice Library. Has anyone used it to serialize a recordset? Any examples?
thanks
Nice Library. Has anyone used it to serialize a recordset? Any examples?
thanks
The problem with this is that something like an ADO Recordset is incredibly far richer than JSON.Quote:
Originally Posted by hbrofman
JSON is so feature poor it is hard to know where to begin. Just look at data types:
JSON only has one numeric type: "number." That's instead of bytes, 16-bit and 32-bit integers, single-precision and double precision floating point, and more. JSON has no byte array. JSON has no date and time types. The list just goes on and on and on. Most of the culprit here is the incredibly type-poor JavaScript that JSON is based upon.
JSON lacks all kinds of metadata. For example a Recordset tracks whether a row has been modified, which is important when marshalling data back to a server for updating so you can send only the modified rows back... and if you send it all back the server can see which rows are to be updated to the underlying datastore at its end. The Fields within a Recordset also carry lots of metadata like the data type, ActualSize and DefinedSize, NumericScale, Precision, the Value and OriginalValue and UnderlyingValue, and more.
If you really want to serialize ADO Recordsets you may be far better off using one of the two formats it supports natively: ADO's own XML format or its ADTG binary format (far more compact).
Now, if you must have JSON and your needs are really meager you can cobble something up. However it is hard to imagine any generic way of doing this for all Recordsets. You must make massive compromises and those must be chosen for every use case.
Nothing says you can't invent some sort of JSON schema for doing this, much as ADO has its XML schema for representing Recordsets. i haven't seen anyone even attempt it yet though. There just isn't enough demand.
I suspect most people dealing with JSON are also dealing with servers that can't handle a Recordset anyway. So in that case they just use some ad hoc JSON schema that implements some tiny fraction of the metadata, if any at all, and live with the data type limitations.
But in that case there just isn't much to it. Any example would have to imply so many assumptions about the specific application as to be meaningless, probably useless for any other application.
the built-in one on the recordset is pretty good if you don't mind using the disk:Quote:
Originally Posted by hbrofman
to disk:
from disk:Code:rs.save("c:\temp.dat",adPersistADTG)
Code:rs.open("c:\temp.dat","Provider=MSPersist")
hi. looking to used JsonBag and did an initial test to check the existence of keys.
how can i do the following as below raises an error
i know JB.Exists("sample") works fine, but checking for a 2nd key ie JB.Exists("fudge") does notCode:If JB.Exists("sample").Item("fudge") = True Then
Debug.Print JB.Item("sample").Item("fudge")
End If
thanks
Hello,
Look, I think there is a bug in the Exists method of the last version, copy this code and replace the Exists procedure:
About how to use it in chain:Code:Public Function Exists(ByVal Key As Variant) As Boolean
Dim Name As String
If VarType(Key) = vbString Then
On Error Resume Next
Name = Names.Item(PrefixHash(Key))
Else
On Error Resume Next
Name = Names.Item(Key)
End If
Exists = Err.Number = 0
Err.Clear
End Function
The word .Item is optional. (whether you put it or not it works anyway)Code:If JB.Exists("sample") Then
If JB("sample").Exists("fudge") Then
Debug.Print JB.Item("sample").Item("fudge")
' Or
Debug.Print JB("sample")("fudge")
End If
End If
thanks Eduardo. If JB("sample").Exists("fudge") Then was what i needed. Did not change the Exists though. left it as is and works fineQuote:
Originally Posted by Eduardo-
Code:Public Function Exists(ByVal Key As Variant) As Boolean
Dim Hash As Long
Dim PrefixedKey As String
Dim Name As String
If VarType(Key) = vbString Then
HashData StrPtr(Key), Len(Key) * 2, VarPtr(Hash), 4
PrefixedKey = Right$("0000000" & Hex$(Hash), 8) & Key
On Error Resume Next
Name = Names.Item(PrefixedKey)
Else
On Error Resume Next
Name = Names.Item(Key)
End If
Exists = Err.Number = 0
Err.Clear
End Function
I am looking to load json data to a treeview but don't know how.
can anyone help or give small example to help
many thanks.
I'm not sure how useful something like that is.
Normally you don't expose JSON to users any more than they should be looking at XML, INI, or any other persistence format. These are meant to store things like program settings that seldom change, descriptions of things like user interface layouts, or as data interchange formats.
If you really want this for some weird reason though it seems simple enough, for example:
Attachment 166223
Here I used different icon images to illustrate whether a node contains an "Object," "Array," "Property," or "Element." Blue for parent nodes and red for leaf nodes.
thanks dilettante, that's just what i was looking for. i am trying to make a little app to help me create code that gets the json from web data.Quote:
Originally Posted by dilettante
usually i go through the json picking what i want and some times its hard to get the right combination
ie p.item("root").item("blah").item("bitmore")
then sometimes i create a for next to load in arrays of data and type this all manually.
With this i can create a rightclick on a node and poss create the path and bits of code i need to paste into my own apps
saves me typing and trial and error to get the right path.
again , many thanks
Don't suppose you would have any example of syntax highlighting json similar to thisQuote:
Originally Posted by dilettante
Attachment 166227
again, thanks