1 files changed, 116 insertions, 0 deletions
diff --git a/docs/samples/save_custom_writer.cpp b/docs/samples/save_custom_writer.cpp
new file mode 100644
index 0000000..e777a32
--- /dev/null
+++ b/docs/samples/save_custom_writer.cpp
@@ -0,0 +1,116 @@
+#include "pugixml.hpp"
+
+#include <string>
+#include <iostream>
+#include <cstring>
+
+// tag::code[]
+struct xml_string_writer: pugi::xml_writer
+{
+    std::string result;
+
+    virtual void write(const void* data, size_t size)
+    {
+        result.append(static_cast<const char*>(data), size);
+    }
+};
+// end::code[]
+
+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_string("<foo bar='baz'>hey</foo>");
+
+    // get contents as std::string (single pass)
+    std::cout << "contents: [" << node_to_string(doc) << "]\n";
+
+    // get contents into fixed-size buffer (single pass)
+    char large_buf[128];
+    std::cout << "contents: [" << node_to_buffer(doc, large_buf, sizeof(large_buf)) << "]\n";
+
+    // get contents into fixed-size buffer (single pass, shows truncating behavior)
+    char small_buf[22];
+    std::cout << "contents: [" << node_to_buffer(doc, small_buf, sizeof(small_buf)) << "]\n";
+
+    // get contents into heap-allocated buffer (two passes)
+    char* heap_buf = node_to_buffer_heap(doc);
+    std::cout << "contents: [" << heap_buf << "]\n";
+    delete[] heap_buf;
+}
+
+// vim:et