convert a string variable into eR64 from DOM parser

[Sundancekid]

Dear all,

while parsing a xml file with the DOM parser some values in the attributes are read as string variables although they contain only numbers plus decimal point.

I've learned from the help file that "File.Formatter.ParseString" should do the job to convert thge string into a numeric value, but I stumbled to get it working.

How do I initialize the File.Formatter.ParseString method, with which object?

Regards,

Rainer

[AndreasK]

Using this class should work too.

I assume its faster because of the missing interface call.

Just use

dim autoLocale : set autoLocale = new CNumLocale

...

dim val : val = CDbl(textVal)

once at the beginning of your ReadStore function.

Or with the formatter:

dim Formatter : Formatter = File.Formatter

Formatter.DecimalPoint = "."

...

dim dataPointNb : dataPointNb = formatter.ParseString(textVal, eR64)

Please set the formatter to an variable.

File.Formatter.ParseString

is slidely slower than

Formatter.ParseString

because of indirection.

But this tip is for each . in an big loop.

'/**
' @brief  Class to set the locale to en-us and set it back when the script finishes
'         This is important to make sure that '.' is interpreted as decimal point
'
' @code
'   dim autoLocale : set autoLocale = new CNumLocale
'   dim val : val = CDbl("1.234")
'   autoLocale = NULL
' @endcode
'*/
Class CNumLocale
 
  '/**
  ' @brief  Initialization will set the locale to english to make sure that the
  '         decimal numbers are interpreted with '.' as decimal point
  '*/
  Private Sub Class_Initialize  
    originalLocale_ = GetLocale
    SetLocale "en-us"
  End Sub

  '/**
  ' @brief  Deinitialization of the class. This method is called automatially and
  '         Will set the locale back to the original value
  '*/
  Private Sub Class_Terminate   
    SetLocale originalLocale_
  End Sub

  private originalLocale_ '///< Old locale setting that will be reestablished after work finished
End Class

[AndreasK]

Another Tip for reading xml from DOM tree and some helper methods.

dim textVal : textVal = XmlValue(parentNode)

is much faster than

dim textVal : textVal = parentNode.textValue

I do not know why. Would asume the internal implementation is the same.

'/**
' @brief Get a child element with the given name
' @param  elem  The dom element to search a sub child in
' @param  name  The name of the the sub element. If "" is given as name the first child
'                       element is picked
' @return a DOMElement object. Use set to assign it to a variable
'*/
Function XmlChild(ByRef elem, ByRef name)

  if 1 <> elem.nodeType Then XmlError "This variable is no DOMElement!"

  Set XmlChild = Nothing

  Dim childElem : For each childElem in elem.childNodes
 
    If 1 = childElem.nodeType then
      ' Only use DOMElements
      if ("" = name) OR (name = childElem.nodeName) then
      
        set XmlChild = childElem
        Exit For
      End if
    
    End If
 
  Next

End Function


'/**
' @brief Count all child element with the given name
' @param  elem  The dom element to search sub childs of
' @param  name  The name of the the sub elements. If "" is given as name all child elements are counted
' @return Number of sub elements with the given name
'*/
Function XmlCountChilds(ByRef elem, ByRef name)
 
  XmlCountChilds = 0

  Dim childElem
  if "" = name then
     For each childElem in elem.childNodes
      If 1 = childElem.nodeType then
        ' Only use DOMElements
        XmlCountChilds = XmlCountChilds + 1
      End If
    Next
  else
    For each childElem in elem.childNodes
      If 1 = childElem.nodeType then
        ' Only use DOMElements
        if name = childElem.nodeName then
          XmlCountChilds = XmlCountChilds + 1
        End if
      End If
    Next
  end if
End Function


'/**
' @brief Get all child element with the given name
' @param  elem  The dom element to search sub childs of
' @param  name  The name of the the sub elements. If "" is given as name all child elements are returned
' @return An array of DOMElements which can be iterated using foreach...
'*/
Function XmlChilds(ByRef elem, ByRef name)

  if 1 <> elem.nodeType Then XmlError "This variable is no DOMElement!"
  dim numOfChilds : numOfChilds = XmlCountChilds(elem, name)

  dim rv : redim rv(numOfChilds - 1)

  Dim childElem
  dim index
  if "" = name then
     index = 0
     For each childElem in elem.childNodes
     If 1 = childElem.nodeType then
        ' Only use DOMElements
        set rv(index) = childElem
        index = index + 1
      End If
    Next
  else
    index = 0
    For each childElem in elem.childNodes
     If 1 = childElem.nodeType then
        ' Only use DOMElements
        if name = childElem.nodeName then
          set rv(index) = childElem
          index = index + 1
        End if
      End If
    Next
  end if

  XmlChilds = rv
End Function

'/**
' @brief Get the value of a given attribute
' @param  elem The DOMElement to look for an attached attribute
' @param  name  Name of the attribute
' @return A string containing the attribute value. If the attribute was not found an error is raised
' @code
' <elem attrib="1232"/>
' dim value : value = XmlAttribute(elem, "attrib")
' Will return 1232 as CString
' @endcode
'*/
Function XmlAttribute(ByRef elem, ByRef name)

  if 1 <> elem.nodeType Then XmlError "This variable is no DOMElement!"

  XmlAttribute = NULL
  dim attrib : set attrib = elem.Attributes.getNamedItem(name)
  if attrib Is Nothing then
    XmlError "Attribute """ & name & """ does not exist on this element!"
  end if
 
  XmlAttribute = attrib.nodeValue

End Function

'/**
' @brief Get the value of a given attribute if the attribute does not exist "" is returned
' @param  elem The DOMElement to look for an attached attribute
' @param  name  Name of the attribute
' @return A string containing the attribute value. If the attribute was not found an error is raised
' @code
' <elem attrib="1232"/>
' dim value : value = XmlAttribute(elem, "attrib")
' Will return 1232 as CString
' @endcode
'*/
Function XmlAttributeNoRaise(ByRef elem, ByRef name)

  if 1 <> elem.nodeType Then XmlError "This variable is no DOMElement!"

  dim attrib : set attrib = elem.Attributes.getNamedItem(name)
  if attrib Is Nothing then
    XmlAttributeNoRaise = ""
  Else
    XmlAttributeNoRaise = attrib.nodeValue
  end if
 
End Function

'/**
' @brief Get value of the embedded DOMTextElement
' @param  elem The DOMElement to look for an embedded text element
' @return A string containing the attribute value. If none text element is embedded "" is returned
' @code
' <elem>abc</elem>
' dim value : value = XmlValue(elem)
' Will return abc as CString
'
' and
'
' <elem/>
' dim value : value = XmlValue(elem)
' Will return "" as CString
' @endcode
'*/
Function XmlValue(ByRef elem)

  if 1 <> elem.nodeType Then XmlError "This variable is no DOMElement!"

  XmlValue = ""

  Dim childElem : For each childElem in elem.childNodes
 
    If 3 = childElem.nodeType then
      ' Only use DOMText
      XmlValue = childElem.nodeValue
    End If
    
  Next

End Function

'/**
' @brief Get the name of a DOMElement
' @param  elem  Element to get the name of
' @return The name of the element. If the given element is not a DOMElement an error is raised
'*/
Function XmlName(ByRef elem)

  if 1 <> elem.nodeType Then XmlError "This variable is no DOMElement!"
 
  XmlName = elem.nodeName

End Function

'/**
' @brief  Raise an vbs error with the given description
' @param  errorDescription  Error description to be attached to the raised error
'*/
Sub XmlError(ByRef errorDescription)
    Err.Description = errorDescription
    Err.Raise 6
End Sub

[Brad_Turpin]

Hi SundanceKid,

The File.Formatter.ParseString function is ONLY available in a DataPlugin.  There is no way to inistantiate such a File object in a regular DIAdem VBScript because that function is not resident in DIAdem's VBScript host.  Only the DataPlugin VBScript host has this implemented.

If you are in a DataPlugin, then you can provide the datatype to use when parsing the string value in the one parameter this function uses:

IntValue = File.Formatter.ParseString(eI32)

RealValue = File.Formatter.ParseString(eR64)

StringValue = File.Formatter.ParseString(eString)

Set TimeValueObj = File.Formatter.ParseString(eTime)

Note that this function assumes you are dealing with a delimited ASCII file (say values separated by commas or tab characters).  It will not succeed in getting the next XML tag value.

Brad Turpin

DIAdem Product Support Engineer
National Instruments