XmlParseError class

The XmlParseError exception class catches parsing errors (including syntax, translation, and encoding errors) thrown by the deserialization methods: LoadXml and WebReceive of the Janus SOAP XmlDoc_API, and the ParseXml method of the HttpResponse class.

This class is available as of Sirius Mods Version 7.6.

The XmlParseError methods

The following are the available XmlParseError class methods.

Method	Description
CharacterPosition	Position of character at of before which the error occurred
Description	Brief description of the exception
InputHexValue	Hexadecimal value of bytes causing the exception
New	Create a new XmlParseError object
Reason	Enumerated cause of the exception

The methods in the class are described in the subsections that follow. In addition:

• "Notation conventions for methods" has information about the conventions followed.
• "XmlParseError methods syntax" is a single page that contains the syntax diagrams of all the methods in the class.

CharacterPosition property

Position of character at of before which the error occurred (XmlParseError class)

This ReadOnly property returns a number that indicates the position within the input character stream (starting with 1) at or before which the error was detected.

Syntax

%number = xmlParseError:CharacterPosition

Syntax terms

%number	The position at or before which the error was detected.
xmlParsError	A reference to an instance of an XmlParseError object.

Usage notes

• The number of bytes that constitute a character depends on the type of string that causes the exception:
  • If EBCDIC, one byte corresponds to one character.
  • If Unicode, two bytes correspond to one character.
  • If UTF-16, two bytes correspond to one character.
  • If UTF-8, the relationship between bytes and characters is variable, depending on the code points.

Description property

Brief description of the exception (XmlParseError class)

This ReadOnly property returns a string that contains a brief description of the exception.

Syntax

%string = xmlParseError:Description

Syntax terms

%string	A string to receive the description of the exception.
xmlParsError	A reference to an instance of a XmlParseError object.

InputHexValue property

Hexadecimal value of bytes causing the exception (XmlParseError class)

This ReadOnly property returns a string that contains the hexadecimal representation of the bytes that caused the exception to be thrown.

InputHexvalue returns a value for all reasons except SyntaxError.

Syntax

%string = xmlParseError:InputHexValue

Syntax terms

%string	A string to receive the hexadecimal value of the bytes that caused the exception to be thrown.
xmlParsError	A reference to an instance of a XmlParseError object.

New constructor

Create a new XmlParseError object (XmlParseError class)

This constructor generates an instance of an XmlParseError exception. As shown in the syntax that follows, the New method arguments set the values of the class properties that have the corresponding names.

Each argument to New sets the value of the corresponding property of the newly constructed XmlParseError object.

Syntax

%xmlParseError = [%(XmlParseError):]New( Reason= xmlParseErrorReason, - [CharacterPosition= number], - [Description= string], - [InputHexValue= string])

Syntax terms

xmlParsError	A reference to an instance of a XmlParseError object.
%(XmlParseError)	The class name in parentheses denotes a shared method.
Reason	This name required parameter specifies the value to be assigned to the exception object's Reason property. Reason settings are XmlParseErrorReason enumeration values. The Reason parameter is not optional.
CharacterPosition	This optional, but name required, parameter specifies the numeric value (number) to be assigned to the object's CharacterPosition property. Its default value is 0.
Description	This optional, but name required, parameter specifies the string value (string) to be assigned to the object's Description property. Its default value is a null string.
InputHexValue	This optional, but name required, parameter specifies the string value (string) to be assigned to the object's InputHexValue property. Its default value is a null string.

Reason property

Enumerated cause of the exception (XmlParseError class)

This ReadOnly property returns an XmlParseErrorReason enumeration value that describes the error that caused the XmlParseError exception.

Syntax

%xmlParseErrorReason = xmlParseError:Reason

Syntax terms

%reason	This XmlParseErrorReason enumeration value (see below) describes the parsing error.
xmlParsError	A reference to an instance of a XmlParseError object.

XmlParseErrorReason enumeration

An XmlParseErrorReason enumeration may have one of the following values, each of which is demonstrated in the examples below.

InvalidUnicodeCharacter

The Unicode input contains an invalid character.

InvalidUTF8Encoding

The input UTF8 stream is invalid.

InvalidUTF16Encoding

The input UTF16 stream is invalid.

SyntaxError

A violation of the syntax of an XML document.

UntranslatableEBCDIC

The EBCDIC input contains a character that is not translatable to Unicode.

UntranslatableISOn

The ISO-8859-n input contains a character that is not translatable to Unicode.

UntranslatableUnicode

The Unicode input contains a character that is not translatable to EBCDIC. This exception can be avoided using the AllowUntranslatable option of the deserialization method.

Example

The following template is used to apply the LoadXml deserialization method to a series of test input-string values to demonstrate the XmlParseError exception output:

try printText {~}: {%d:LoadXml(input-string)} catch XmlParseError to %err print ' ' print 'Error Reason:' And %err:Reason:ToString print 'Error Description:' And %err:Description print 'Error Character Position:' And %err:CharacterPosition print 'Error Input Hex Value:' And %err:InputHexValue print ' - - -' end try

• When called with:

  %d:LoadXml('<a>'):

  The results are:

  Error Reason: SyntaxError Error Description: XML doc parse error: missing ETag for top level element near or before position 4 (end of input) Error Character Position: 4 Error Input Hex Value: - - -

• When called with:

  %d:LoadXml('<' With 'FF':X With '>')

  The results are:

  Error Reason: UntranslatableEBCDIC Error Description: XML doc parse error: EBCDIC character not translatable to Unicode near or before position 3 Error Character Position: 3 Error Input Hex Value: FF - - -

• When called with:

  %d:LoadXml('<a>&#x2122;</a>':U)

  The results are:

  Error Reason: UntranslatableUnicode Error Description: XML doc parse error: invalid Unicode character - not translatable to EBCDIC near or before position 5 Error Character Position: 5 Error Input Hex Value: 2122 - - -

• When called with:

  %d:LoadXml('FEFF003C33':X)

  The results are:

  Error Reason: InvalidUTF16Encoding Error Description: XML doc parse error: expecting additional byte of UTF-16 encoding near or before position 2 (end of input) Error Character Position: 2 Error Input Hex Value: 33 - - -

• When called with:

  %d:LoadXml('FEFFD800':X)

  The results are:

  Error Reason: InvalidUnicodeCharacter Error Description: XML doc parse error: surrogate point in UTF-16 input near or before position 1 Error Character Position: 1 Error Input Hex Value: D800 - - -

• When called with:

  %d:LoadXml('C181':X)

  The results are:

  Error Reason: InvalidUTF8Encoding Error Description: XML doc parse error: byte 1 of 2 too low in UTF-8 encoding near or before position 2 Error Character Position: 2 Error Input Hex Value: C181 - - -

• When called with:

  %d:LoadXml('FF818256':X)

  The results are:

  Error Reason: InvalidUTF8Encoding Error Description: XML doc parse error: attempt to use 4-byte UTF-8 encoding of surrogate point near or before position 2 Error Character Position: 2 Error Input Hex Value: FF - - -

• When called with:

  %d:LoadXml('EDA080':X)

  The results are:

  Error Reason: InvalidUnicodeCharacter Error Description: XML doc parse error: invalid Unicode character (surrogate range) near or before position 2 Error Character Position: 2 Error Input Hex Value: EDA080 - - -