Method: JS::Object#method_missing

Defined in:
lib/js.rb

#method_missing(sym, *args, &block) ⇒ Object

Provide a shorthand form for JS::Object#call

This method basically calls the JavaScript method with the same name as the Ruby method name as is using JS::Object#call.

Exceptions are the following cases:

  • If the method name ends with a question mark (?), the question mark is removed and the method is called as a predicate method. The return value is converted to a Ruby boolean value automatically.

This shorthand is unavailable for the following cases and you need to use JS::Object#call instead:

  • If the method name is invalid as a Ruby method name (e.g. contains a hyphen, reserved word, etc.)

  • If the method name is already defined as a Ruby method under JS::Object

  • If the JavaScript method name ends with a question mark (?)



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# File 'lib/js.rb', line 184

def method_missing(sym, *args, &block)
  sym_str = sym.to_s
  if sym_str.end_with?("?")
    # When a JS method is called with a ? suffix, it is treated as a predicate method,
    # and the return value is converted to a Ruby boolean value automatically.
    result = invoke_js_method(sym_str[0..-2].to_sym, *args, &block)
    # Type coerce the result to boolean type
    # to match the true/false determination in JavaScript's if statement.
    return ::JS.global.Boolean(result) == ::JS::True
  end

  invoke_js_method(sym, *args, &block)
end