Question

Backbone’s model.save() method has the following signature:

model.save([attributes], [options])

I want to call it, but I don’t want to pass in any attributes, only options. I need it this way because I set the attributes before saving using model.set(attributes).

How can I pass in just one object to model.save() but indicate that it is the options object and not the attributes object?

Answer 1

The documentation is explicit on this so we have to look at the source:

save: function(key, val, options) {
  var attrs, current, done;

  // Handle both `"key", value` and `{key: value}` -style arguments.
  if (key == null || _.isObject(key)) {
    attrs = key;
    options = val;
  } else if (key != null) {
    (attrs = {})[key] = val;
  }

And below that you’ll see various if (attrs ...) checks. So if you say

m.save(null, options)

you’ll save the model as-is and you’ll be able to set your options. Furthermore, if you say this:

m.save(some_attrs, options);

then that is (more or less) the same as:

m.set(some_attrs);
m.save(null, options);