V8, append text to the last element of the array

Question

I'm building a native NodeJS C++ module based on V8. I got the following code in loop:

Local<Array> nodes = Array::New();

/********** INSIDE THE LOOP ************/
Local<Object> node_obj = Object::New();
node_obj->Set(data_symbol, String::New(input.substr(openPos + (lastTag > 1 ? 3 : 2), pos - openPos - (lastTag > 1 ? 3 : 2) - 1).c_str()));
node_obj->Set(tag_symbol, Integer::New(lastTag));
nodes->Set(id, node_obj);

And I'm populating an array with objects, so the output (in JS) will look like this:

[
    {tag: 2, data: "asdsadsadasfddgdfgdfg"},
    {tag: 1, data: "afg235235232fgdfg"}
]

My questions is how I can append a string to the data_symbol of the last object of the array?

Full code can be found here: http://pastebin.com/tCgWCxyA

Example of what I'm trying to do:

Lets take this structure for example:

struct Node {
    short tag;
    std::string data;

    Node(const std::string& input, short tagId) : tag(tagId), data(input) {}
};

std::vector<Node> elems;

My question is how I can do

elems.back().data.append("SomeString");

in V8?

Answer 1

You can use String::Concat(Handle<String> left, Handle<String>right) like so:

HandleScope scope;

Local<Object> lastnode = nodes->Get(nodes->Length() - 1)->ToObject();
Local<String> lastdatastr = lastnode->Get(data_symbol)->ToString();
lastnode->Set(data_symbol,
              String::Concat(lastdatastr, String::New(" I'm appended!")));