Parsing JSON, Stumped by Array of Objects that are Dictionaries

General
1

I’m using @Kem_Tekinay’s terrific M_JSON classes to parse some incoming JSON that includes a dictionary and several arrays of objects, all of which are dictionaries. Maybe it’s just one of those days where I can’t see the forest for the trees, but I can’t figure out how to retrieve the dictionaries that are within the arrays.

Here’s the relevant code:

Dim v as Variant
v=ParseJSON_MTC(content, False, True) 'Content incoming from the URLConnection

'Returns a dictionary with four entries:
'The first is a dictionary
'The second and third are arrays of 4 objects (ubound=3), all of which are dictionaries
'The fourth is a dictionary

If v IsA Dictionary Then
  
  For Each ky As DictionaryEntry In Dictionary(v)
    
    If ky.Key="latest-build" Then
      
      'A single dictionary, easy
      
    Elseif ky.key="messages" Then
      
      If ky.Value.IsArray Then 'This is an array of objects, all of which are Dictionaries
        
        Dim dvalues As Variant
        
        For j=0 To UBound(Array(ky.Value))
          
          dVal=Dictionary(Array(ky.Value(j))) 'Not an array, but treating it as one" <<<<==== THE PROBLEM LINE
          
          If dVal IsA Dictionary Then
            For Each de As DictionaryEntry In Dictionary(dVal)
              KeyStr=de.Key
              Astr=de.Value
            Next
          End If
          
        Next
        
      End If

etc...

It must be something simple and obvious, thoughts?

Thank you -

  • John
2

Some kind of bug, i’ve reported lately, try:

dVal=Dictionary(Object(Array(ky.Value(j))))

Xojo does return Object() instead of Dictionary() in Variant from ParseJSON

<https://xojo.com/issue/62293>

3

Alas, no luck. Tried Dictionary(Object(Array, Array(Object(Dictionary and every other combination I can think of.

4 
 Var objs() as object = dvalues
 For each obj as object in objs
 Var d as Dictionary = dictionary(obj)
 // do something with the doctionary.
 // catch exceptions too!
 Next

You can check the examples in the feeback report

5

Very clever, great thinking outside the box. Once again, the people on this forum are the BEST, thank you!

1 Like
6

FYI, when parsing JSON, you’ll only get one of two structures: Dictionary or Variant(), so this should work:

if ky.Value.IsArray then
  dim arr() as Variant = ky.Value
  for each d as Dictionary in arr
  ...
7

@Kem_Tekinay Not when receiving… again see the feedback case.
<https://xojo.com/issue/62293>

Internally ParseJSON uses Object() instead of Dictionary() so you must convert.
GenerateJSON does use Dictionary since you can’t parse objects() into it or it will trow an exception.

8

I know what the debugger says, but it’s an array of Variant. Try the code I posted to see.

9

Or try this code:

var s as string = "{""main"":[{""a"":1},{""b"":2}, true, null]}"
var d as Dictionary = ParseJSON( s )


var arr() as variant = d.Value( "main" )
for each child as variant in arr
  if child.Type = Variant.TypeObject then
    MessageBox Introspection.GetType( child ).Name
  else
    MessageBox child.Type.ToString
  end if
next