iOS Question check if a kvs custom type contains an element

[marcick]

I have a KeyValueStore that contains custom type

Type LocCfg(Password As String, Confirmed As Boolean, Cdate As Long)

Now I need to add a field and I modify like this

Type LocCfg(Password As String, Confirmed As Boolean, Cdate As Long, NewField as int)

I publish on the store the new app

First time the new app is run, the existing kvs does not have the NewField, so I'm trying to do like this

Dim par As LocCfg=KvsLocCfg.Get(key1)
if par.NewField=null or par.NewField="" then par.NewField=0
dim x as int=par.NewField

But it generate a "null" error

Also adding a Try-Catch does not work

Dim par As LocCfg=KvsLocCfg.Get(key1)
Dim x as int
try
    x=par.NewField
catch
   x=0
End Try

Which is the correct way to manage this ?

 

[kstainsb]

Could you define a new data type LocCfg2 with the new data elements. Then get the object from kvs, and do a check. If obj is LocCfg then...else if obj is LocCfg2 ... etc?

 

[Erel]

Could you define a new data type LocCfg2 with the new data elements. Then get the object from kvs, and do a check. If obj is LocCfg then...else if obj is LocCfg2 ... etc?

This is a good option. You can also add LocCfg as a field in LocCfg2. This way you will only need to add the new field.

But it generate a "null" error

Can you post the full error message?

 

[marcick]

Thanks, I’ll try and be back soon.

 

[marcick]

Dim par As LocCfg=KvsLocCfg.Get(key1)
if par.NewField=null or par.NewField="" then par.NewField=0
dim x as int=par.NewField

The error in the last instruction is: "Cannot parse: (null)"

I feel there is a simpler way to solve, but I did like this and seems to work:

Dim parold As LocCfg
Dim parnew As LocCfg2
Dim xx As Object
For Each k As String In MySub.KvsLocCfgWeb.ListKeys
      xx=MySub.KvsLocCfgWeb.get(k)
      If xx Is LocCfgWeb Then
           parold=MySub.KvsLocCfgWeb.Get(k)
           parnew.Password=parold.Password
           parnew.Cdate=parold.Cdate
           parnew.NewField=0
           MySub.KvsLocCfgWeb.put(k,parnew)
      End If
Next