如何将nil序列化为JSON，而不是空位？

Question

In my controller/action I have some values that are nil

def my_action
  @var1 = get_boolean_value || nil
  @var2 = get_int_value || nil
  @var3 = get_string_value || nil

  # there many more, any one can happen to be nil
end

When I create a JSON object in a view out of them, nil values get rendered as an empty space:

:javascript
  window.MyObj = {
    var1: #{@var1},
    var2: #{@var1},
    var2: #{@var3}
  }

The issue is that when a value is nil, it's rendered as an empty space, not nil itself.

:javascript
  window.MyObj = {
    var1: ,
    var2: 33,
    var2: 
  }

How to cure that?

Answer 1

One should not reinvent the wheel. Use JSON ruby standard library to serialize json:

require 'json'
json = {var1: nil, var2: 42, var2: nil}.to_json
#⇒ "{\"var1\":null,\"var2\":42,\"var3\":null}"

and then:

:javascript
  window.MyObj = json