PowerBuilder

Call a JavaScript Function Returning an Integer

See more JavaScript Examples

Demonstrates how to call a JavaScript function that returns an integer. PowerBuilder

integer li_rc
integer li_Success
oleobject loo_SbScript
oleobject loo_Js
oleobject loo_Result
oleobject loo_FuncCall
integer li_Retval

li_Success = 0

// ----------------------------------------------------------------------------------
// The Javascript function called in this example is shown at the bottom of this page.
// -----------------------------------------------------------------------------------

// In this example, we'll load the Javascript function definition from a file.
// It doesn't need to come from a file.  It could just as easily be loaded from a string.
loo_SbScript = create oleobject
li_rc = loo_SbScript.ConnectToNewObject("Chilkat.StringBuilder")
if li_rc < 0 then
    destroy loo_SbScript
    MessageBox("Error","Connecting to COM object failed")
    return
end if
li_Success = loo_SbScript.LoadFile("js_call_function.js","utf-8")
if li_Success = 0 then
    Write-Debug loo_SbScript.LastErrorText
    destroy loo_SbScript
    return
end if

// Note: Each instance of a Chilkat Js object automatically establishes
// its own internal runtime and context.  Applications do not need to explicitly create
// the JavaScript runtime or context.
loo_Js = create oleobject
li_rc = loo_Js.ConnectToNewObject("Chilkat.Js")

loo_Result = create oleobject
li_rc = loo_Result.ConnectToNewObject("Chilkat.JsonObject")

loo_Result.EmitCompact = 0

// Call Eval to add the function (shown at the bottom of this page) to the context's global object
li_Success = loo_Js.Eval(loo_SbScript,loo_Result)
if li_Success = 0 then
    // Examine the result for an exception.
    Write-Debug loo_Result.Emit()

    // Also examine the LastErrorText.
    Write-Debug loo_Js.LastErrorText
    destroy loo_SbScript
    destroy loo_Js
    destroy loo_Result
    return
end if

Write-Debug loo_Result.Emit()

// The expected output is "undefined":

// {
//   "type": "undefined",
//   "value": "undefined"
// }

//    When Eval processes a script containing only a function declaration,
//    it successfully performs the action (the function becomes defined).
//    However, since the script consists of a statement that produces no value,
//    the script's overall completion value is empty. In JavaScript, the
//    absence of a value is represented by `undefined`.
// 
//    Therefore, the Eval call returns `undefined`.

// ------------------------------------------------------------------------------
// Call the function calculateScore("Player1", 10, 20)

loo_FuncCall = create oleobject
li_rc = loo_FuncCall.ConnectToNewObject("Chilkat.JsonObject")

// Create JSON defining the function call:

// {
//   "name": "calculateScore",
//   "args": [ "Player1", 10, 20 ]
// }

loo_FuncCall.UpdateString("name","calculateScore")
loo_FuncCall.UpdateString("args[0]","Player1")
loo_FuncCall.UpdateInt("args[1]",10)
loo_FuncCall.UpdateInt("args[2]",20)

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

li_Success = loo_Js.CallFunction(loo_FuncCall,loo_Result)
if li_Success = 0 then
    // Examine the result for an exception.
    Write-Debug loo_Result.Emit()

    // Also examine the LastErrorText.
    Write-Debug loo_Js.LastErrorText
    destroy loo_SbScript
    destroy loo_Js
    destroy loo_Result
    destroy loo_FuncCall
    return
end if

Write-Debug loo_Result.Emit()

// Output:

// {
//   "type": "int",
//   "value": 37
// }

li_Retval = loo_Result.IntOf("value")
Write-Debug "retval = " + string(li_Retval)


destroy loo_SbScript
destroy loo_Js
destroy loo_Result
destroy loo_FuncCall