I am trying to enumerate the 'Keys' in a Gambas decoded JSON file. If I run the code below I can print the data associated with the key but not the keys.


I am looking to get a list of 'Keys' into an array ["BTC_BCN","BTC_BELA",…] and ["id","last","lowestAsk"…]. Any ideas appreciated.

(Click to enlarge)

Try this:-

Thanks SteveDee. There is no doubt that this works but I am having trouble getting my head around the logic. I haven't worked out how to get the next set of 'Keys', but this is a start, thanks.  :?

The clues are in your first post, but I don't know how much time you have spent playing around with Collections. As your screen shots show, vNew contains a collection of collections. Each trading pair in the collection contains its own collection of data, where the trading pair name is the Key string.

So I've taken the variant vNew (which is returned from Json.Decode) and copied it into the new collection cBitcoin. Then I enumerate each item in the collection cBitcoin by asking: "FOR EACH collection (ciBitcoin) IN the collection (cBitcoin) please return the Key"

The collection property cBitcoin.Key returns each collection key as a string (e.g. BTC_ETH). And then I can use:

…to get the corresponding Last value.

In VB6 you could also access a collection using a numeric index, something like:
…would give you the 3rd item Key in the collection. But Gambas does not support a numeric index.

I'm glad you used the Poloniex api query: "https://poloniex.com/public?command=returnTicker"
..as the main collection only references sub-collections, which makes the code straight forward.

As an additional exercise, I spent an hour or two this morning trying to do the same thing with:
 "https://www.cryptocompare.com/api/data/coinlist/"
This collection includes a mixture of strings and collections, and I can't think how to deal with this.

What additional data are you trying to retrieve? The remaining data for each trading pair in your example is similar to "last". So for example, if you wanted the 24hr High value use:


And if you want to filter trading pairs, you could just display Ether markets:

I hope this helps, but come back if its still gibberish.

As an additional exercise, I spent an hour or two this morning trying to do the same thing with:
"https://www.cryptocompare.com/api/data/coinlist/"
This collection includes a mixture of strings and collections, and I can't think how to deal with this.

I think that should be pretty easy actually. A recursive function to do the data extraction, and start it with a test like this:/lang/is - Gambas Documentation

(Haven't actually run this code)

Yes, I discussed it with #3 son last night (he is doing Computer Science at Uni, but does not code in Gambas) and this morning I came up with this:-


Wow! there are 1507 cryptos listed on this site!

The important bit is the For Each line that just enumerates the "Data" object in the json text. The rest just puts the text into an array and creates pretty-text.

This started with a question from Brad on the 'other' forum (which seems to be a forum no longer). I managed to sort the problem for which I recveived the heart warming "Awesome! Thank you so much!" but I thought I'd dig further and automatically get all the data into arrays. The URL I am using came from Brad.

Your solution worked but confused me as I have only ever enumerated with the variable after 'Each' not with the variable after 'In'

e.g.
For Each ciBitcoin In cBitcoin
  Print ciBitcoin.Key
Next

But you worked with ciBitcoin, it works but I can't work out the logic here.

For Each ciBitcoin In cBitcoin
  Print cBitcoin.Key
Next

I was trying to get a list of the other keys as well ["id","last",lowestAsk"…].

Using your example website you end up with a list of keys ["Response", "Message"…"Data"…] then ["LC", "HEAT", "EXB"…] and open up the Collection and there are more keys ["id", "Url", "ImageUrl"…].

Basically I can get the information out as I can see keys like "last" but I thought it would be nice for Gambas to get all that detail for me.

cogier said

…Your solution worked but confused me as I have only ever enumerated with the variable after 'Each' not with the variable after 'In'

e.g.
For Each ciBitcoin In cBitcoin
  Print ciBitcoin.Key
Next

But you worked with ciBitcoin, it works but I can't work out the logic here.

For Each ciBitcoin In cBitcoin
  Print cBitcoin.Key
Next

Take a look at this For Each…In… example:-




This "Cars" collection consists of 4 string elements, each one has an integer value assigned to it.
We could print the integer value of an individual element by directly addressing the element, e.g.


…would result in: 3

But by creating a string variable ("Make") we can specify that we want to step through each string element in Cars, assign it to Make and then print the corresponding integer value for Make. The result is that the integers are printer in the order they appear in the collection: 2 1 4 3

In the Crypto example, I am not looking for a string element in the Collection, I'm looking for other Collection elements. So I Dim a collection ("ciBitcoin") and use this:-

 Reading my last post again this morning, I realise something is not quite right with my explanation.

Although the Cars example appears to work, the variable "Make" should be an integer, not a string. The reason it appears to work as a string is that Gambas just quietly converts each integer into a string.

Even if you replace the integers in this example with booleans (True or False) the code still runs without error, but converts True to "T" and false to "".

Thanks for all the effort here. I can't get much from the Jornmo example. I tried the following


This got me: -
Key: id Value: 7
Key: id Value: 8
Key: id Value: 10
Key: id Value: 12
Key: id Value: 13
Key: id Value: 14
…….

Thanks for the explanation SteveDee

I discussed it with #3 son last night (he is doing Computer Science at Uni, but does not code in Gambas)

    He'll need lots of these then "{}{}{}{}{}{}{}".  

Going to the pub now, I will get a friend to look at all this and see if he can add anything to this debate.

 I can't get much from the Jornmo example. I tried the following

Try replacing:


With:

Your code works but the 'TypeOf (v)' is never 'True' so is not called.

This code will get the 'Keys' of the 1st and 2nd depth.


Result
…..
BTC_OMG
ETH_OMG
BTC_GAS
ETH_GAS
id
last
lowestAsk
highestBid
percentChange
baseVolume
quoteVolume
isFrozen
high24hr
low24hr

Your code works but the 'TypeOf (v)' is never 'True' so is not called.

I suppose that's because your JSON file does not produce collections inside a collection, as with stevedee?!

Hi Guys,

TypeOf(v) is true, if you pass the whole result from Json.decode… see below


Results:
Collection: Key: BTC_BCN
Key: id Value: 7
Key: last Value: 0.00000034
Key: lowestAsk Value: 0.00000035
Key: highestBid Value: 0.00000034
Key: percentChange Value: -0.02857142
Key: baseVolume Value: 39.58161827
Key: quoteVolume Value: 115639167.85117029
Key: isFrozen Value: 0
Key: high24hr Value: 0.00000036
Key: low24hr Value: 0.00000033
Collection: Key: BTC_BELA
Key: id Value: 8
Key: last Value: 0.00003115
…

Hi Guys,

I think the "Collection" could do with a ".Keys" as well as ".Key" function…. ?

In the meantime, see my GetKeys(Collection) function below:


Cheers
Matt

 If you tick "Do not automatically parse URLs" below the posting form, the URL's will display properly inside the code highlighter. (I will sooner or later need to make the plugin skip parsing automatically)

I think the "Collection" could do with a ".Keys" as well as ".Key" function…. ?

Agree  8-)

i am getting unknown identifier Json error
anyone can help ?

<IMG src="https://pix.cobrasoftwares.org/images/2022/03/28/Screenshot-from-2022-03-28-21-57-02.png">

Welcome to the forum.

Try going to Project > Properties… > Components and ensure you have the gb.util.web component loaded.

<IMG src="https://www.cogier.com/gambas/Json1.png"> </IMG>

Hello! New to Gambas here. I was trying to do an example using httpClient instead of Wget but no matter what i always end getting Null when i try to JsonDecode.
Does anyone know what i may be doing wrong here? Any help is appreciated.

Hi DayanUt31 and welcome to the forum.

I suggest you start a 'New Topic' next time you have a question.
Tip: - When adding Gambas code to your posts use the 'gb' button. The code looks a lot better, see below
<IMG src="https://www.cogier.com/gambas/gb_button.png"> </IMG>  

Regarding your query, put the code below in a Graphical Application and run it, hopefully it will answer some of your questions.

Thank you a lot for your help! i was able to understand more about Json decode in gambas.
I made some small adjustements to the code you provide before so instead i can get the data collection printed in a terminal.
This is how it looks:


Just one last question.
For some reason, when i try to change the url from this example to this one:
https://jsonplaceholder.typicode.com/users

it gives me an error telling me "Wanted string, got Collection instead"
<IMG src="https://ibb.co/54RGPZP"> </IMG>

why is this? and do you know how could i adapt this code to work with this specific Url?
thanks for all the support.

Did you include the  "<a href=" parts by mistake?
url strings were added to the URL by the forum and should not be there (Charlie forgot to select the  "Do not automatically parse URLs" option)

this is not right…

it should just be this..

or this even

Did you include the "<a href=" parts by mistake?
url strings were added to the URL by the forum and should not be there (Charlie forgot to select the "Do not automatically parse URLs" option)

Opps! :?
I have fixed this.

The reason that the new URL creates a crash is due to the fact that there are Collections inside the Collections and I notice, there is another Collection inside that!
<IMG src="https://www.cogier.com/gambas/Collections.png"> </IMG>

The code below will skip over the error. Programming the code further depends on what your program is expecting to achieve.

Thank you very much for all the help, i managed to get it running like this:


The only bad thing is i get different results in the company name. It shows like this "company :       (Collection 0x56185d800b98)"
I was thinking i could get around this by adding an if inside the for each so it can change it to Collection or variant depending on the result in vVal but i would need to give it a try.