PowerBuilder

Check if Integer Exists at JSON Path

Demonstrates how to get an integer value at a JSON path, and how to check to see if it exists. PowerBuilder

integer li_rc
integer li_Success
oleobject loo_Json
string ls_Path
integer li_Val
integer li_WasFound

li_Success = 0

loo_Json = create oleobject
li_rc = loo_Json.ConnectToNewObject("Chilkat.JsonObject")
if li_rc < 0 then
    destroy loo_Json
    MessageBox("Error","Connecting to COM object failed")
    return
end if

// First build simple JSON..
loo_Json.UpdateInt("test.abc",100)

loo_Json.EmitCompact = 0
Write-Debug loo_Json.Emit()

// This is our JSON:
// {
//   "test": {
//     "abc": 100,
//   }
// }

ls_Path = "test.notHere"

// The call to IntOf will return 0, because it's not present.
// But how do we know if it really was present, and the value was truly 0?
li_Val = loo_Json.IntOf(ls_Path)
Write-Debug "val = " + string(li_Val)

// We cannot use LastMethodSuccess because LastMethodSuccess only applies
// to methods that:
// - return a string
// - return a new Chilkat object, binary bytes, or a date/time.
// - returns a boolean status where 1 = success and 0 = failed.
// - returns an integer where failure is defined by a return value less than zero.
// The IntOf method fits none of these requirements, and therefore the LastMethodSuccess 
// is not a valid indicator..
li_WasFound = loo_Json.LastMethodSuccess
Write-Debug "wasFound = " + string(li_WasFound) + " (not a valid indicator)"

// Instead, if the returned value is 0, we can double-check to see if the member was truly there..
if li_Val = 0 then
    li_WasFound = loo_Json.HasMember(ls_Path)
    Write-Debug "wasFound = " + string(li_WasFound)
    if li_WasFound = 1 then
        Write-Debug "The value was present and is 0."
    else
        Write-Debug "no member is present at test.notHere"
    end if

else
    Write-Debug "val = " + string(li_Val)
end if

// Alternatively, you could check to see if the member exists beforehand..
if loo_Json.HasMember(ls_Path) = 1 then
    Write-Debug "val = " + string(loo_Json.IntOf(ls_Path))
else
    Write-Debug "no member at " + ls_Path
end if



destroy loo_Json