Android Question [B4A] PrefDialog.PrefItems.Set

[T201016]

Hello,
Can someone explain to me what is wrong with the performance,
Look:
PrefDialog.PrefItems.Set(0, newItem) ?

    ...


    PrefDialog.Initialize(Parent, "Dialog", 300dip, 400dip)

    PrefDialog.LoadFromJson(File.ReadString(File.DirAssets, "template.json"))

 

    ...

 

    Dim oldItem As String = PrefDialog.PrefItems.Get(0)

    Dim newItem As Object = SFX.MidExtract(oldItem,"Title=","]","Duplicate Record")

    PrefDialog.PrefItems.Set(0, newItem) ------------------ >>> ERROR

java.lang.ClassCastException:
java.lang.String cannot be cast to b4a.example.preferencesdialog
$_b4xprefitem



Used procedures:

'Used to extract text from a string between to other blocks of text,
'and converted to a new text last parameter function.
Public Sub MidExtract(paramString1 As String, paramString2 As String, paramString3 As String, paramString4 As String) As Object
    Private str As String = ""

    If (LenString(paramString1) = 0) Then Return ""
    If paramString2.Length = 0 And paramString3.Length = 0 Then    Return paramString1
    If ((paramString1.Contains(paramString2)) And (paramString1.Contains(paramString3))) Then

        str = paramString1.Substring2(paramString1.IndexOf(paramString2), paramString1.indexOf(paramString3))
        str = str.Substring2(paramString2.Length, str.Length).Trim
      
        str = paramString1.Replace(str, paramString4).Trim
    
        Return str
    Else
        Return ""
    End If
End Sub

'Returns the length of this string.
Public Sub LenString(paramString1 As String) As Int
    Return paramString1.Length
End Sub

template.json

{
    "Version": 1.1,
    "Theme": "Light Theme",
    "Items": [
        {
            "title": "Edit Record",
            "type": "Separator",
            "key": "",
            "required": false
        },
        {
            "title": "First Name",
            "type": "Text",
            "key": "FirstName",
            "required": true
        },
        {
            "title": "Last Name",
            "type": "Text",
            "key": "LastName",
            "required": true
        },
        {
            "title": "Company",
            "type": "Text",
            "key": "Company",
            "required": true
        },
        {
            "title": "Address",
            "type": "Text",
            "key": "Address",
            "required": true
        },
        {
            "title": "Email",
            "type": "Text",
            "key": "Email",
            "required": true
        }
    ]
}

 

[Erel]

0. Please use [code]code here...[/code] tags when posting code.

1. First step is to remove this MidExtract code. You don't need it. If you want to parse JSON then use JSON library.
2. Post the full error message from the logs.
3. What are you trying to do?

 

[T201016]

Hello Erel,

3.
In the file 'template.json'
I want to replace the title of a dialog
from "title": "Edit Record" to "title": "xxxxxxxxxx xxxxx"

 

[T201016]

Of course by using: PrefDialog.PrefItems.Set (0, newItem)

 

[Erel]

As I wrote, the first step is to remove this MidExtract code. It is really impossible to fix any code based on it.

A simple solution is to parse the json file, replace the value in the map and generate a new json string.

Dim parser As JSONParser
parser.Initialize(s)
Dim m As Map = parser.NextObject
Dim items As List = m.Get("Items")
For Each item As Map In items
    If item.Get("title") = "Edit Record" Then
        item.Put("title", "new title")
    End If
Next
Dim gen As JSONGenerator
gen.Initialize(m)
Log(gen.ToPrettyString(4))

 

[T201016]

Welcome back,
Thanks to Erel for solving the problem, and I will check the example below soon.

Your code seems to be working so the thread can be closed.