docs: Fixed sample comment, adding load error handling sample, added custom writer sample

git-svn-id: http://pugixml.googlecode.com/svn/trunk@552 99668b35-9821-0410-8761-19e4c4f06640

docs/samples/load_error_handling.cpp

@@ -0,0 +1,29 @@
+#include "pugixml.hpp"
+
+#include <iostream>
+
+void check_xml(const char* source)
+{
+//[code_load_error_handling
+	pugi::xml_document doc;
+	pugi::xml_parse_result result = doc.load(source);
+
+	if (result)
+		std::cout << "XML [" << source << "] parsed without errors, attr value: [" << doc.child("node").attribute("attr").value() << "]\n\n";
+	else
+	{
+		std::cout << "XML [" << source << "] parsed with errors, attr value: [" << doc.child("node").attribute("attr").value() << "]\n";
+		std::cout << "Error description: " << result.description() << "\n";
+		std::cout << "Error offset: " << result.offset << " (error at [..." << (source + result.offset) << "]\n\n";
+	}
+//]
+}
+
+int main()
+{
+	check_xml("<node attr='value'><child>text</child></node>");
+	check_xml("<node attr='value'><child>text</chil></node>");
+	check_xml("<node attr='value'><child>text</child>");
+	check_xml("<node attr='value\"><child>text</child></node>");
+	check_xml("<node attr='value'><#tag /></node>");
+}

docs/samples/load_memory.cpp

@@ -22,7 +22,7 @@ int main()
 
 	{
 	//[code_load_memory_buffer_inplace
-		// You can use load_buffer_inplace to load document from mutable memory block; memory blocks lifetime must exceed that of document
+		// You can use load_buffer_inplace to load document from mutable memory block; the block's lifetime must exceed that of document
 		char* buffer = new char[size];
 		memcpy(buffer, source, size);
 

docs/samples/save_custom_writer.cpp

@@ -0,0 +1,112 @@
+#include "pugixml.hpp"
+
+#include <string>
+
+#include <stdio.h>
+
+struct xml_string_writer: pugi::xml_writer
+{
+	std::string result;
+
+	virtual void write(const void* data, size_t size)
+	{
+		result += std::string(static_cast<const char*>(data), size);
+	}
+};
+
+struct xml_memory_writer: pugi::xml_writer
+{
+	char* buffer;
+	size_t capacity;
+
+	size_t result;
+
+	xml_memory_writer(): buffer(0), capacity(0), result(0)
+	{
+	}
+
+	xml_memory_writer(char* buffer, size_t capacity): buffer(buffer), capacity(capacity), result(0)
+	{
+	}
+
+	size_t written_size() const
+	{
+		return result < capacity ? result : capacity;
+	}
+
+	virtual void write(const void* data, size_t size)
+	{
+		if (result < capacity)
+		{
+			size_t chunk = (capacity - result < size) ? capacity - result : size;
+
+			memcpy(buffer + result, data, chunk);
+		}
+
+		result += size;
+	}
+};
+
+std::string node_to_string(pugi::xml_node node)
+{
+	xml_string_writer writer;
+	node.print(writer);
+
+	return writer.result;
+}
+
+char* node_to_buffer(pugi::xml_node node, char* buffer, size_t size)
+{
+	if (size == 0) return buffer;
+
+	// leave one character for null terminator
+	xml_memory_writer writer(buffer, size - 1);
+	node.print(writer);
+
+	// null terminate
+	buffer[writer.written_size()] = 0;
+
+	return buffer;
+}
+
+char* node_to_buffer_heap(pugi::xml_node node)
+{
+	// first pass: get required memory size
+	xml_memory_writer counter;
+	node.print(counter);
+
+	// allocate necessary size (+1 for null termination)
+	char* buffer = new char[counter.result + 1];
+
+	// second pass: actual printing
+	xml_memory_writer writer(buffer, counter.result);
+	node.print(writer);
+
+	// null terminate
+	buffer[writer.written_size()] = 0;
+
+	return buffer;
+}
+
+int main()
+{
+	// get a test document
+	pugi::xml_document doc;
+	doc.load("<foo bar='baz'>hey</foo>");
+
+	// get contents as std::string (single pass)
+	printf("contents: [%s]\n", node_to_string(doc).c_str());
+
+	// get contents into fixed-size buffer (single pass)
+	char large_buf[128];
+	printf("contents: [%s]\n", node_to_buffer(doc, large_buf, sizeof(large_buf)));
+
+	// get contents into fixed-size buffer (single pass, shows truncating behavior)
+	char small_buf[22];
+	printf("contents: [%s]\n", node_to_buffer(doc, small_buf, sizeof(small_buf)));
+
+	// get contents into heap-allocated buffer (two passes)
+	char* heap_buf = node_to_buffer_heap(doc);
+	printf("contents: [%s]\n", heap_buf);
+	delete[] heap_buf;
+}