How can I get the keys of a node.js hash from a C++ module?

Question

I have a C++ module that's being called from node.js. I would like to pass in a hash and retrieve both the keys and values from the C++ code but I cannot figure out how to get them. Here's what I would like to handle:

var mod = require('MyModule')
var conn = mod.createConnection()
conn.connect( { 'uid': 'graeme',
                'pwd': 'mypassword' } )

Inside my C++ method, I can use args[0]->IsObject() to determine that the parameter is a hash, but I can't find a way to get the keys ('uid', 'pwd') or the values ('graeme', 'mypassword') from it.

Is there a way to get the keys and values from these kinds of objects?

Answer 1

Your second example of passing in an array doesn't really make sense, but to your general point, you can use GetOwnPropertyNames to read the names of properties.

Local<Object> obj = args[0].As<Object>();
Local<Array> props = obj->GetOwnPropertyNames();

for (int i = 0, len = props->Length(); i < len; i++){
    Local<String> key = props->Get(i).As<String>();
    Local<Value> val = obj->Get(key);
}

equivalent to:

var props = Object.getOwnPropertyNames(arguments[0]);
for (var i = 0, len = props.length; i < len; i++){
    var key = props[i];
    var value = arguments[0][key];
}