' Copyright 2011 ESRI
' 
' All rights reserved under the copyright laws of the United States
' and applicable international laws, treaties, and conventions.
' 
' You may freely redistribute and use this sample code, with or
' without modification, provided you include the original copyright
' notice and use restrictions.
' 
' See the use restrictions.
' 

Imports Microsoft.VisualBasic
Imports System
Public Class Utility
  ' Constructs a callback result that will display an error message based on the passed-in
  ' exception
  Public Shared Function GetErrorCallback(ByVal exception As System.Exception) As ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResult
    ' Create a callback result to display an error message
    Dim jsAlertErrorMessage As String = GetJavaScriptErrorString(exception)
    Dim alertCallbackResult As ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResult = ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResult.CreateJavaScript(jsAlertErrorMessage)
    Return alertCallbackResult
  End Function

  ' Constructs JavaScript necessary to display an error message based on the passed-in exception.
  Public Shared Function GetJavaScriptErrorString(ByVal exception As System.Exception) As String
    ' Get the website's configuration file
    Dim webConfig As System.Configuration.Configuration = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration(System.Web.HttpContext.Current.Request.ApplicationPath)

    ' Get the "compilation" section of the config file
    Dim compilationSection As System.Web.Configuration.CompilationSection = TryCast(webConfig.GetSection("system.web/compilation"), System.Web.Configuration.CompilationSection)

    ' If the config file's compilation section specifies debug mode, include 
    ' stack trace information in the error message.  Otherwise, just return 
    ' the exception message.
    Dim errorMessage As String = Nothing
    If (Not compilationSection Is Nothing) AndAlso (compilationSection.Debug) Then
      Dim stackTrace As String = exception.StackTrace.Replace("\", "\\")
      stackTrace = stackTrace.Replace(Constants.vbLf, "\n")
      stackTrace = stackTrace.Replace(Constants.vbCr, "\r")
      stackTrace = stackTrace.Replace("'", "\'")
      errorMessage = exception.Message.Replace("\", "\\")
      errorMessage = errorMessage.Replace(Constants.vbLf, "\n")
      errorMessage = errorMessage.Replace(Constants.vbCr, "\r")
      errorMessage = errorMessage.Replace("'", "\'")

      errorMessage = errorMessage & "\n\n" & stackTrace.Trim()
    Else
      errorMessage = exception.Message
    End If

    ' Create a callback result to display an error message
    Dim jsAlertException As String = "alert('" & errorMessage & "')"
    Return jsAlertException
  End Function

  Public Shared Function CreateErrorCallback(ByVal message As String) As ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResultCollection
    ' Create a string containing the JavaScript necessary to display an alert with the passed-in 
    ' message as text
    Dim jsAlertException As String = "alert('" & message & "')"
    ' Create a callback result encapsulating the JavaScript
    Dim alertCallbackResult As ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResult = ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResult.CreateJavaScript(jsAlertException)

    ' Create a Web ADF CallbackResultCollection and add the callback results created above to it
    Dim callbackResultCollection As ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResultCollection = New ESRI.ArcGIS.ADF.Web.UI.WebControls.CallbackResultCollection()
    callbackResultCollection.Add(alertCallbackResult)

    Return callbackResultCollection
  End Function

  Friend Shared Function FindControl(ByVal controlID As String, ByVal page As System.Web.UI.Page) As System.Web.UI.Control
    ' Make sure the passed-in page and control are not null
    If page Is Nothing OrElse controlID Is Nothing Then
    Return Nothing
    End If

    ' Try getting a reference to the control being sought via the page's FindControl function
    Dim webControl As System.Web.UI.Control = page.FindControl(controlID)

    ' Check whether the control was found
    If webControl Is Nothing Then
      ' Call method to traverse the Page's controls and find the unique id of the control
      ' having the passed in control ID
      Dim uniqueControlID As String = GetControlUniqueID(controlID, page.Controls)
      If Not uniqueControlID Is Nothing Then
        webControl = page.FindControl(uniqueControlID)
      Else
        webControl = page.FindControl(controlID)
      End If
    End If
    Return webControl
  End Function

  Friend Shared Function GetControlUniqueID(ByVal controlID As String, ByVal controls As System.Web.UI.ControlCollection) As String
    ' Declare a Control object to store references to controls in the passed-in ControlCollection
    Dim control As System.Web.UI.Control
    ' Declare a string variable to store references to the UniqueIDs of controls in the passed-in
    ' collection
    Dim uniqueID As String = Nothing

    ' Iterate through the controls in the passed-in collection
    Dim i As Integer = 0
    Do While i < controls.Count
      ' Get a reference to the current control
      control = controls(i)

      ' Check whether the current control's ID matches the passed in control ID
      If control.ID = controlID Then
        ' The control's ID matches, so get a reference to its UniqueID and exit the loop
        uniqueID = control.UniqueID
        Exit Do
      End If

      ' Check whether the current control contains any child controls
      If control.Controls.Count > 0 Then
        ' Recursively call GetControlUniqueID with the passed-in control ID and the current
        ' control's collection of child controls
        uniqueID = GetControlUniqueID(controlID, control.Controls)
        ' Check whether the ID was found.  If so, exit the loop
        If Not uniqueID Is Nothing Then
          Exit Do
        End If
      End If
      i += 1
    Loop
    Return uniqueID
  End Function

  Friend Shared Function RenderControlHtml(ByVal webControl As System.Web.UI.Control) As String
    ' Instantiate StringWriter and HtmlTextWriter objects to render the control to and
    ' retrieve the control's HTML
    Dim stringWriter As System.IO.StringWriter = New System.IO.StringWriter()
    Dim htmlTextWriter As System.Web.UI.HtmlTextWriter = New System.Web.UI.HtmlTextWriter(stringWriter)

    ' Render the passed-in control to the HtmlTextWriter
    webControl.RenderControl(htmlTextWriter)
    ' Retrieve the control's html as a string from the StringWriter.  The state
    ' of the StringWriter is automatically updated via its reference to the HtmlTextWriter
    Dim htmlContent As String = stringWriter.ToString()
    ' Since we are done with the StringWriter, close it
    stringWriter.Close()

    ' Return the control's HTML as a string
    Return htmlContent
  End Function
End Class