/// <summary>
/// Performs validation on the xml source as well as evaluates conditional and flow expresions
/// </summary>
/// <exception cref=".">For invalid use of conditional expressions or for invalid XML syntax. If a XmlValidatingReader is passed, then will also throw exceptions for non-schema-conforming xml</exception>
/// <param name="reader"></param>
/// <returns>the output xml </returns>
public string Process(XmlReader reader)
{
if(reader == null)
throw new ArgumentException("Invalid XML reader to pre-process");
IfContext context = new IfContext(true, true, IfState.None);
StringWriter xmlText = new StringWriter();
XmlTextWriter writer = new XmlTextWriter(xmlText);
writer.Formatting = Formatting.Indented;
while(reader.Read())
{
if(reader.NodeType == XmlNodeType.ProcessingInstruction)
{
bool ignore = false;
switch(reader.LocalName)
{
case "if":
m_IfStack.Push(context);
context = new IfContext(context.Keep & context.Active, ParseExpression(reader.Value), IfState.If);
ignore = true;
break;
case "elseif":
if(m_IfStack.Count == 0)
throw new WarningException("Unexpected 'elseif' outside of 'if'");
else if(context.State != IfState.If && context.State != IfState.ElseIf)
throw new WarningException("Unexpected 'elseif' outside of 'if'");
context.State = IfState.ElseIf;
if(!context.EverKept)
context.Keep = ParseExpression(reader.Value);
else
context.Keep = false;
ignore = true;
break;
case "else":
if(m_IfStack.Count == 0)
throw new WarningException("Unexpected 'else' outside of 'if'");
else if(context.State != IfState.If && context.State != IfState.ElseIf)
throw new WarningException("Unexpected 'else' outside of 'if'");
context.State = IfState.Else;
context.Keep = !context.EverKept;
ignore = true;
break;
case "endif":
if(m_IfStack.Count == 0)
throw new WarningException("Unexpected 'endif' outside of 'if'");
context = (IfContext)m_IfStack.Pop();
ignore = true;
break;
}
if(ignore)
continue;
}//end pre-proc instruction
if(!context.Active || !context.Keep)
continue;
switch(reader.NodeType)
{
case XmlNodeType.Element:
bool empty = reader.IsEmptyElement;
writer.WriteStartElement(reader.Name);
while (reader.MoveToNextAttribute())
writer.WriteAttributeString(reader.Name, reader.Value);
if(empty)
writer.WriteEndElement();
break;
case XmlNodeType.EndElement:
writer.WriteEndElement();
break;
case XmlNodeType.Text:
writer.WriteString(reader.Value);
break;
case XmlNodeType.CDATA:
writer.WriteCData(reader.Value);
break;
default:
break;
}
}
if(m_IfStack.Count != 0)
throw new WarningException("Mismatched 'if', 'endif' pair");
return xmlText.ToString();
}
/// <summary>
/// Performs validation on the xml source as well as evaluates conditional and flow expresions
/// </summary>
/// <exception cref=".">For invalid use of conditional expressions or for invalid XML syntax. If a XmlValidatingReader is passed, then will also throw exceptions for non-schema-conforming xml</exception>
/// <param name="reader"></param>
/// <returns>the output xml </returns>
public string Process(XmlReader reader)
{
if (reader == null)
{
throw new ArgumentException("Invalid XML reader to pre-process");
}
IfContext context = new IfContext(true, true, IfState.None);
StringWriter xmlText = new StringWriter();
XmlTextWriter writer = new XmlTextWriter(xmlText);
writer.Formatting = Formatting.Indented;
while (reader.Read())
{
if (reader.NodeType == XmlNodeType.ProcessingInstruction)
{
bool ignore = false;
switch (reader.LocalName)
{
case "if":
m_IfStack.Push(context);
context = new IfContext(context.Keep & context.Active, ParseExpression(reader.Value), IfState.If);
ignore = true;
break;
case "elseif":
if (m_IfStack.Count == 0)
{
throw new WarningException("Unexpected 'elseif' outside of 'if'");
}
else if (context.State != IfState.If && context.State != IfState.ElseIf)
{
throw new WarningException("Unexpected 'elseif' outside of 'if'");
}
context.State = IfState.ElseIf;
if (!context.EverKept)
{
context.Keep = ParseExpression(reader.Value);
}
else
{
context.Keep = false;
}
ignore = true;
break;
case "else":
if (m_IfStack.Count == 0)
{
throw new WarningException("Unexpected 'else' outside of 'if'");
}
else if (context.State != IfState.If && context.State != IfState.ElseIf)
{
throw new WarningException("Unexpected 'else' outside of 'if'");
}
context.State = IfState.Else;
context.Keep = !context.EverKept;
ignore = true;
break;
case "endif":
if (m_IfStack.Count == 0)
{
throw new WarningException("Unexpected 'endif' outside of 'if'");
}
context = (IfContext)m_IfStack.Pop();
ignore = true;
break;
}
if (ignore)
{
continue;
}
} //end pre-proc instruction
if (!context.Active || !context.Keep)
{
continue;
}
switch (reader.NodeType)
{
case XmlNodeType.Element:
bool empty = reader.IsEmptyElement;
writer.WriteStartElement(reader.Name);
while (reader.MoveToNextAttribute())
{
writer.WriteAttributeString(reader.Name, reader.Value);
}
if (empty)
{
writer.WriteEndElement();
}
break;
case XmlNodeType.EndElement:
writer.WriteEndElement();
break;
case XmlNodeType.Text:
writer.WriteString(reader.Value);
break;
case XmlNodeType.CDATA:
writer.WriteCData(reader.Value);
break;
default:
break;
}
}
if (m_IfStack.Count != 0)
{
throw new WarningException("Mismatched 'if', 'endif' pair");
}
return(xmlText.ToString());
}
