Add support for substrings

IO/vtkXMLParser.cxx

@@ -22,16 +22,17 @@
 #include <ctype.h>
 #include <sys/stat.h>
 
-vtkCxxRevisionMacro(vtkXMLParser, "1.11");
+vtkCxxRevisionMacro(vtkXMLParser, "1.12");
 vtkStandardNewMacro(vtkXMLParser);
 
 //----------------------------------------------------------------------------
 vtkXMLParser::vtkXMLParser()
 {
-  this->Stream      = 0;
-  this->Parser      = 0;
-  this->FileName    = 0;
-  this->InputString = 0;
+  this->Stream            = 0;
+  this->Parser            = 0;
+  this->FileName          = 0;
+  this->InputString       = 0;
+  this->InputStringLength = 0;
 }
 
 //----------------------------------------------------------------------------
@@ -61,11 +62,23 @@ void vtkXMLParser::PrintSelf(ostream& os, vtkIndent indent)
 int vtkXMLParser::Parse(const char* inputString)
 {
   this->InputString = inputString;
+  this->InputStringLength = -1;
   int result = this->vtkXMLParser::Parse();
   this->InputString = 0;
   return result;
 }
 
+//----------------------------------------------------------------------------
+int vtkXMLParser::Parse(const char* inputString, unsigned int length)
+{
+  this->InputString = inputString;
+  this->InputStringLength = length;
+  int result = this->vtkXMLParser::Parse();
+  this->InputString = 0;
+  this->InputStringLength = -1;
+  return result;
+}
+
 
 //----------------------------------------------------------------------------
 int vtkXMLParser::Parse()
@@ -135,7 +148,14 @@ int vtkXMLParser::ParseXML()
   // Parsing of message
   if ( this->InputString )
     {
-    return this->ParseBuffer(this->InputString);
+    if ( this->InputStringLength >= 0 )
+      {
+      return this->ParseBuffer(this->InputString, this->InputStringLength);
+      }
+    else
+      {
+      return this->ParseBuffer(this->InputString);
+      }
     }
 
   // Make sure we have input.

IO/vtkXMLParser.h

@@ -56,8 +56,10 @@ public:
   virtual int Parse();
 
   // Description:
-  // Parse the XML message.
+  // Parse the XML message. If length is specified, parse only the
+  // first "length" characters
   virtual int Parse(const char* inputString);
+  virtual int Parse(const char* inputString, unsigned int length);
 
   // Description:
   // Set and get file name.
@@ -76,6 +78,7 @@ protected:
   
   // Character message to parse
   const char* InputString;
+  int InputStringLength;
   
   // Expat parser structure.  Exists only during call to Parse().
   void* Parser;