Need some examples for new JSON library as of LC8

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sphere
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Location: the Netherlands

Need some examples for new JSON library as of LC8

Post by sphere » Sat Jul 29, 2017 2:20 pm

Hello,
does anyone have some examples on how to use the new JSON library?

I'm strugling a bit with it.
I'm trying the example from this page:http://forums.livecode.com/viewtopic.ph ... ON#p155118
Using the json data which i load fine as a test file from my website.
Then i use the example on the last post from Jim on that page.

But it seems not to work.

So if anyone has some more basics to play with, it would be great.

thanks a lot.
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jacque
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Re: Need some examples for new JSON library as of LC8

Post by jacque » Sat Jul 29, 2017 8:34 pm

How does it fail for you? One thing that does matter is that the JSON has to be well-formed or the function will fail. I usually wrap it in a "try" structure and report the error if one occurs. You can check for malformed JSON here:
http://json.parser.online.fr/

Here's what I usually do:

Code: Select all

put url tURL into tJSON
try
  put JSONToArray(tJSON) into tJSONArray
catch tErr
  answer tErr -- this should give some clue
end try
If the error is something about being unable to read the JSON, it's likely malformed. I usually see a list of LC error codes when that happens.

Some people have had better results using JsonImport() instead. You might try that too.
Jacqueline Landman Gay | jacque at hyperactivesw dot com
HyperActive Software | http://www.hyperactivesw.com

sphere
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Joined: Sat Sep 27, 2014 10:32 am
Location: the Netherlands

Re: Need some examples for new JSON library as of LC8

Post by sphere » Sat Jul 29, 2017 8:43 pm

Thanks, this is a nice thing to try. I will do so tomorrow and report back. I had to watch the quarter final Womens Soccer Euro Championship. Yoohoo :lol: we won again, now from Sweden: NL-SE 2-0 :D :D :D and now going to watch Germany-Denmark, the winner of that will have to compete the Dutch in the Semi-Final :)

***edit*** the match Ger-DM is prosponed, because of to much rain......

So i have some time now to check.
Thanks for the link: it had indeed 2 faults, now they are corrected. (it's just the json from the forum page as noted above, to test how this works exactly)

I do not get any error, but the widget is also not filled with data, maybe i'm overlooking something.
script in button:

Code: Select all

local tProfile,tURL,tJSON,tArray
on mouseUp
  put "https://mysite.nl/folder/json_test/test.json" into tURL
   put url tURL into tJSON
   answer tJSON    
if the result begins with "error" then
   answer"something is not good"
else
   answer"ok"
   try
      put JasonToArray("CRITERIA") into tArray
   catch tErr
      answer tErr -- this should give some clue
   end try
  set the arrayData of widget "Tree View" to tArray
end if
end mouseUp
script in stack:

Code: Select all

local tArray,tJSON,count
function JasonToArray whatType
    answer"function called"
   repeat for each key x in tJSON["feed"]
      add 1 to count
      if  tJSON["feed"] [x] ["type"] is whatType then put tJSON["feed"] [x] into tArray[count]
   end repeat
   return tArray
end JasonToArray
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sphere
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Re: Need some examples for new JSON library as of LC8

Post by sphere » Sat Jul 29, 2017 9:16 pm

don't know if it's a false flag, but Microsoft Essentials gets nervous of playing on that JSON parser site, using the items in the right corner :twisted: Samples-->All JS Types
trojan.PNG
trojan.PNG (5.34 KiB) Viewed 616 times
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jacque
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Re: Need some examples for new JSON library as of LC8

Post by jacque » Sun Jul 30, 2017 5:38 am

I mis-read what you are doing. There is a built-in function named "JSONtoArray" and that's what I use. I see now that you are using a custom function, "JasonToArray" which is something different. It apparently extracts lines of a particular type from a larger JSON string. Using a "try" structure here won't do much, since the function doesn't throw any errors if there's a problem. You can take it out.

It looks like the JasonToArray function is expecting a LC array, and you are passing a JSON string instead. You'll want to use the built-in JSONtoArray() function to convert the string you receive from the URL into a LC array, and then pass that to the JasonToArray function. If you pass only the raw JSON string, there are no "keys" per se, it's just a string, so the repeat loop won't run and it will return empty.

Secondly, the JSON string is stored in script locals in both the button and in the stack, but that won't share the data between different scripts. A script local variable only has value for the handlers in the same script. You could use a global variable instead but it would be even better (and cleaner) if you pass the JSON as a parameter to the jasonToArray function. As it is now, tJSON will probably be empty in the stack script so there is nothing to process.

Finally, unless the variable "count" is used elsewhere in the stack script, there's no reason to have it as a script-local variable. It can be a handler variable instead.
Jacqueline Landman Gay | jacque at hyperactivesw dot com
HyperActive Software | http://www.hyperactivesw.com

sphere
Posts: 464
Joined: Sat Sep 27, 2014 10:32 am
Location: the Netherlands

Re: Need some examples for new JSON library as of LC8

Post by sphere » Sun Jul 30, 2017 9:49 pm

Yes, thank you Jacque.
What was i thinking....i changed it somehow thinking it was a random name for the function, even though i did read it before in the dictionary. :oops:

Working now :) now i can test some more.

by the way, i googled some and this is also a nice json checkr without giving me security warnings https://jsonlint.com/

Thanks a lot for your clear advise!
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MaxV
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Re: Need some examples for new JSON library as of LC8

Post by MaxV » Wed Aug 09, 2017 12:08 pm

Please note of this bug: http://quality.livecode.com/show_bug.cgi?id=19698
so jsonimpot/jsonexport are not perfect.

this:

Code: Select all

{ 
    "Likes":[
        "noise",
        "animals",
        "chocolate",
        "hitting Izzy",
        "running and screaming"
    ]
}
using jsonexport(jsonimport(temp))
becomes:

Code: Select all

{ 
   "Likes": {
      "5": "running and screaming",
      "1": "noise",
      "2": "animals",
      "3": "chocolate",
      "4": "hitting Izzy"
    }
}
that is a totally different json file.
At the present there is no way to solve this bug, due the nature of the livecode arrays.
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sphere
Posts: 464
Joined: Sat Sep 27, 2014 10:32 am
Location: the Netherlands

Re: Need some examples for new JSON library as of LC8

Post by sphere » Wed Aug 09, 2017 1:24 pm

Yes i noted.
I'm struggling too, to see what's best for me.
As my thoughts are after importing and/or decoding it, it has to be treated as an array internally

so when is use this site http://www.convertcsv.com/csv-to-json.htm
it gives 4 choices of json files, just like you say MaxV

and after importing i'm trying to get it in a datagrid or table field for now to see how i can get a certain result when finding a key(or a value in a column on a certain line)
importing a database seems easier now to me then using this json, but maybe because i have to find the workings and understanding a lot more.
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sphere
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Re: Need some examples for new JSON library as of LC8

Post by sphere » Thu Aug 10, 2017 10:31 pm

the post of Richard Gaskin here viewtopic.php?f=49&t=27980#p146704 got me on the right track

so i exported an ods (open file format) excel like sheet with 12 colums and 23 rows to csv file in LibreOffice.
Then i used JSONedit(you can get it here http://tomeko.net/software/JSONedit/) to get a similair output as the 1st of 4 options from the above mentioned converter-site, so simple csv2json. exported it to json.

then count the number of elements,because csv2json creates an array of objects with keys/values in it
then using combine and a repeat loop i can now find the element which contains the correct key i want to find and put it in a table field

will put an example here tomorrow. This way i did not have to change anything manually to the json file.

So nice learning curve here with this i must say. Did take a while.... :P
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sphere
Posts: 464
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Location: the Netherlands

Re: Need some examples for new JSON library as of LC8

Post by sphere » Fri Aug 11, 2017 4:37 pm

So the JSON file i have is similair like this, only only shortened it and changed the actual data:

Code: Select all

    [	
	{
		"Board" : "50",
		"Counterweight" : "100,
		"ElectricalPower" : "120",
		"ElectricalType" : "US",
	},
	
	{
		"Board" : "60",
		"Counterweight" : "110",
		"ElectricalPower" : "230",
		"ElectricalType" : "UK",
	},
	
	{
		"Board" : "70",
		"Counterweight" : "120",
		"ElectricalPower" : "230",
		"ElectricalType" : "EU",
	}
	]
Put below script in a button, use an entry field for the data to search for, use a table field to display the found data and search on US UK or EU

Code: Select all

local tMatrix,tArray,tSubArray,tSomuch,tThis,count
on mouseUp
   put empty into field "Table Field"
  put URL "https://mysite.nl/folder/json_test/test.json" into tMatrix
   --answer tMatrix
 if the result begins with "error" then
    answer "File not loaded!"
    exit to top
--else
   --answer "File loaded OK!"
end if
put fld"search" into tThis
put JSONToArray(tMatrix) into tArray
put the number of elements of tArray into tSomuch--this counts the number of {"data"} between the [] brackets, in this example 3
repeat with x= 1 to tSomuch
   repeat for each key y in tArray[tSomuch]
      add 1 to count
      if  tArray[x][y] is tThis then put tArray[x] into tSubArray    
   end repeat
   if the mouse is down then exit repeat--just for test to bail out
  end repeat
   combine tSubArray by return and tab
  put tSubArray after field "Table Field"
end mouseUp
it will put both the key and the value of the found element into 2 columns of the datafield
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