How to get inner XML of a node in pugixml?

I parse a document and want to retrieve part of the XML tree as string. The document (example):

<?xml version="1.0"?> <MyConfig> <MyData> <Foo bar="baz>42</Foo> </MyData> <OtherData>Something</OtherData> </MyConfig> 

The code:

 pugi::xml_document doc; doc.load_file(documentFileName); pugi::xml_node root = doc.child("MyConfig"); // parse custom data _customData = root.child("MyData"). <-- HOW TO GET INNER XML? 

Expected contents of custom data (if formatting is lost, I don't mind):

"<Foo bar="baz>42</Foo>" 

How to do this?

2 Answers

I found a solution directly in the docs, it's just that google does not index them well, so I had to look it up manually. My solution was to use pugi::xml_writer and node.print. In the docs, they even already show an implementation for std::string:

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); } }; 

With that available, I just made a convenience function to merge XML of all child nodes:

std::string InnerXML(pugi::xml_node target) { xml_string_writer writer; for (pugi::xml_node child = target.first_child(); child; child = child.next_sibling()) child.print(writer, ""); return writer.result; } 

I think pugi::xml_node::print() is a way.

pugi::xml_node node = root.child("MyData"); pugi::xml_node child = node.first_child(); std::stringstream ss; child.print(ss); std::string s = ss.str(); 

The trouble is that s will now have value

<Foo bar="baz&gt;42&lt;/Foo&gt; &lt;/MyData&gt; &lt;OtherData&gt;Something&lt;/OtherData&gt; &gt; &#10;&lt;/MyConfig&gt;" /> 

1. It's the textual tree from the node onwards, and;
2. It's messy with html escape sequences rather than < and >

Not ideal, but these can obviously be solved with some string manipulation.

// replace &lt; with < size_t off = 0; while ((off = s.find("&lt;", off)) != s.npos) s.replace(off, 4, "<"); // replace &gt; with > off = 0; while ((off = s.find("&gt;", off)) != s.npos) s.replace(off, 4, ">"); // truncate at the closing tag size_t end_open = s.find(">", 0); size_t end_close = s.find(">", end_open + 1); s = s.substr(0, end_close + 1); 

Which will lead to s having value

<Foo bar="baz>42</Foo>