VB.NET

JavaScript console

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Demonstrates console output using Chilkat JavaScript. VB.NET

Dim success As Boolean = False

' This example demonstrates using the built-in console object.
' The Javascript run in this example is shown below.

' Load the JavaScript from a file.
Dim sbScript As New Chilkat.StringBuilder
success = sbScript.LoadFile("qa_data/js_tests/test_console.js","utf-8")
If (success = False) Then
    Debug.WriteLine(sbScript.LastErrorText)
    Exit Sub
End If


Dim js As New Chilkat.Js
Dim result As New Chilkat.JsonObject

' Run the JavaScript
' Results (not console output) go to result.
' Note: Eval returns the completion value of the script. This is generally the value of the last evaluated expression.
' In this case, the last evaluated expression is console.log which does not calculate a value. Therefore, it returns undefined.
success = js.Eval(sbScript,result)
If (success = False) Then
    Debug.WriteLine(sbScript.LastErrorText)
    Exit Sub
End If


' We can look at the result, which is "undefined", which is normal and expected.
Debug.WriteLine(result.Emit())
' The result JSON is: {"type":"undefined","value":"undefined"}

' The console output is retrieved by calling ConsoleOutputSb
Dim sbOut As New Chilkat.StringBuilder
js.ConsoleOutputSb(sbOut)
Debug.WriteLine(sbOut.GetAsString())