Add cmXMLWriter class to consolidate XML generation

Explicitly track XML generation state (indentation, element closure,
etc.) so that clients can avoid manually/implicitly maintaining it.

Source/CMakeLists.txt

@@ -347,6 +347,8 @@ set(SRCS
   cmXMLParser.h
   cmXMLSafe.cxx
   cmXMLSafe.h
+  cmXMLWriter.cxx
+  cmXMLWriter.h
   cmake.cxx
   cmake.h
 

Source/cmXMLWriter.cxx

@@ -0,0 +1,134 @@
+/*============================================================================
+  CMake - Cross Platform Makefile Generator
+  Copyright 2015 Daniel Pfeifer <daniel@pfeifer-mail.de>
+
+  Distributed under the OSI-approved BSD License (the "License");
+  see accompanying file Copyright.txt for details.
+
+  This software is distributed WITHOUT ANY WARRANTY; without even the
+  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+  See the License for more information.
+============================================================================*/
+#include "cmXMLWriter.h"
+#include "cmXMLSafe.h"
+
+#include <cassert>
+#include <fstream>
+
+cmXMLWriter::cmXMLWriter(std::ostream& output, std::size_t level)
+: Output(output)
+, Level(level)
+, ElementOpen(false)
+, BreakAttrib(false)
+, IsContent(false)
+{
+}
+
+cmXMLWriter::~cmXMLWriter()
+{
+  assert(this->Elements.empty());
+}
+
+void cmXMLWriter::StartDocument(const char* encoding)
+{
+  this->Output << "<?xml version=\"1.0\" encoding=\"" << encoding << "\"?>";
+}
+
+void cmXMLWriter::EndDocument()
+{
+  assert(this->Elements.empty());
+  this->Output << '\n';
+}
+
+void cmXMLWriter::StartElement(std::string const& name)
+{
+  this->CloseStartElement();
+  this->ConditionalLineBreak(!this->IsContent, this->Elements.size());
+  this->Output << '<' << name;
+  this->Elements.push(name);
+  this->ElementOpen = true;
+  this->BreakAttrib = false;
+}
+
+void cmXMLWriter::EndElement()
+{
+  assert(!this->Elements.empty());
+  if (this->ElementOpen)
+    {
+    this->Output << "/>";
+    }
+  else
+    {
+    this->ConditionalLineBreak(!this->IsContent, this->Elements.size() - 1);
+    this->IsContent = false;
+    this->Output << "</" << this->Elements.top() << '>';
+    }
+  this->Elements.pop();
+  this->ElementOpen = false;
+}
+
+void cmXMLWriter::BreakAttributes()
+{
+  this->BreakAttrib = true;
+}
+
+void cmXMLWriter::Comment(const char* comment)
+{
+  this->CloseStartElement();
+  this->ConditionalLineBreak(!this->IsContent, this->Elements.size());
+  this->Output << "<!-- " << comment << " -->";
+}
+
+void cmXMLWriter::CData(std::string const& data)
+{
+  this->PreContent();
+  this->Output << "<![CDATA[" << data << "]]>";
+}
+
+void cmXMLWriter::ProcessingInstruction(const char* target, const char* data)
+{
+  this->CloseStartElement();
+  this->ConditionalLineBreak(!this->IsContent, this->Elements.size());
+  this->Output << "<?" << target << ' ' << data << "?>";
+}
+
+void cmXMLWriter::FragmentFile(const char* fname)
+{
+  this->CloseStartElement();
+  std::ifstream fin(fname, std::ios::in | std::ios::binary);
+  this->Output << fin.rdbuf();
+}
+
+void cmXMLWriter::ConditionalLineBreak(bool condition, std::size_t indent)
+{
+  if (condition)
+    {
+    this->Output << '\n' << std::string(indent + this->Level, '\t');
+    }
+}
+
+void cmXMLWriter::PreAttribute()
+{
+  assert(this->ElementOpen);
+  this->ConditionalLineBreak(this->BreakAttrib, this->Elements.size());
+  if (!this->BreakAttrib)
+    {
+    this->Output << ' ';
+    }
+}
+
+void cmXMLWriter::PreContent()
+{
+  this->CloseStartElement();
+  this->IsContent = true;
+}
+
+void cmXMLWriter::CloseStartElement()
+{
+  if (this->ElementOpen)
+    {
+    this->ConditionalLineBreak(this->BreakAttrib, this->Elements.size());
+    this->Output << '>';
+    this->ElementOpen = false;
+    }
+}

Source/cmXMLWriter.h

@@ -0,0 +1,120 @@
+/*============================================================================
+  CMake - Cross Platform Makefile Generator
+  Copyright 2015 Daniel Pfeifer <daniel@pfeifer-mail.de>
+
+  Distributed under the OSI-approved BSD License (the "License");
+  see accompanying file Copyright.txt for details.
+
+  This software is distributed WITHOUT ANY WARRANTY; without even the
+  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+  See the License for more information.
+============================================================================*/
+#ifndef cmXMLWiter_h
+#define cmXMLWiter_h
+
+#include "cmStandardIncludes.h"
+#include "cmXMLSafe.h"
+
+#include <ostream>
+#include <stack>
+#include <string>
+#include <vector>
+
+class cmXMLWriter
+{
+public:
+  cmXMLWriter(std::ostream& output, std::size_t level = 0);
+  ~cmXMLWriter();
+
+  void StartDocument(const char* encoding = "UTF-8");
+  void EndDocument();
+
+  void StartElement(std::string const& name);
+  void EndElement();
+
+  void BreakAttributes();
+
+  template <typename T>
+  void Attribute(const char* name, T const& value)
+    {
+    this->PreAttribute();
+    this->Output << name << "=\"" << SafeAttribute(value) << '"';
+    }
+
+  template <typename T>
+  void Element(std::string const& name, T const& value)
+    {
+    this->StartElement(name);
+    this->Content(value);
+    this->EndElement();
+    }
+
+  template <typename T>
+  void Content(T const& content)
+    {
+    this->PreContent();
+    this->Output << SafeContent(content);
+    }
+
+  void Comment(const char* comment);
+
+  void CData(std::string const& data);
+
+  void ProcessingInstruction(const char* target, const char* data);
+
+  void FragmentFile(const char* fname);
+
+private:
+  cmXMLWriter(const cmXMLWriter&);
+  cmXMLWriter& operator=(const cmXMLWriter&);
+
+  void ConditionalLineBreak(bool condition, std::size_t indent);
+
+  void PreAttribute();
+  void PreContent();
+
+  void CloseStartElement();
+
+private:
+  static cmXMLSafe SafeAttribute(const char* value)
+    {
+    return cmXMLSafe(value);
+    }
+
+  static cmXMLSafe SafeAttribute(std::string const& value)
+    {
+    return cmXMLSafe(value);
+    }
+
+  template <typename T>
+  static T SafeAttribute(T value)
+    {
+    return value;
+    }
+
+  static cmXMLSafe SafeContent(const char* value)
+    {
+    return cmXMLSafe(value).Quotes(false);
+    }
+
+  static cmXMLSafe SafeContent(std::string const& value)
+    {
+    return cmXMLSafe(value).Quotes(false);
+    }
+
+  template <typename T>
+  static T SafeContent(T value)
+    {
+    return value;
+    }
+
+private:
+  std::ostream& Output;
+  std::stack<std::string, std::vector<std::string> > Elements;
+  std::size_t Level;
+  bool ElementOpen;
+  bool BreakAttrib;
+  bool IsContent;
+};
+
+#endif