If you try running any code in chapter 11 you get the same error "Can't set headers after they are sent"

Express 3.0.0beta7
CoffeeScript version 1.3.3
Node v0.8.2

http.js:644
throw new Error('Can't set headers after they are sent.');
^
Error: Can't set headers after they are sent.
at ServerResponse.OutgoingMessage.setHeader (http.js:644:11)
at ServerResponse.res.setHeader (/Users/work/todo/node_modules/express/node_modules/connect/lib/patch.js:62:20)
at ServerResponse.res.header (/Users/work/todo/node_modules/express/lib/response.js:280:8)
at ServerResponse.res.json (/Users/work/todo/node_modules/express/lib/response.js:135:8)
at Create.global.Responder.Responder.complete (/Users/work/todo/src/controllers/responders/responder.js:27:25)
at Promise.__bind (/Users/work/todo/src/controllers/responders/responder.js:3:63)
at Promise.addBack (/Users/work/todo/node_modules/mongoose/lib/promise.js:120:8)
at Promise.EventEmitter.emit (events.js:88:17)
at Promise.emit (/Users/work/todo/node_modules/mongoose/lib/promise.js:59:38)
at Promise.complete (/Users/work/todo/node_modules/mongoose/lib/promise.js:70:20)

Hi

Not sure where you want bug reports about issues in the book? is it ok here? or should I sent to your publisher?

In Chapter 10: section: Setting up MongoDB using Mongoose:

Example 3: app.coffee - you say we need to update our app to include the todo model we just created...I assume you mean we need to update app.coffee with the require todos_controller -- but the image included in the Kindle version I have - does not show any controller line being added - it just repeats a previous code block that did not have any changes to it in this one.

Its missing this line:

require("#{__dirname}/src/controllers/todos_controller")

and the rest of the section expects that you did that - but if you follow explicitly you missed it and won't get the results the book shows! :)

hope this helps someone!

cheers.

Hi

Im starting to run into some trouble with Chapter 10 not working out. I think this is the same as your other issue which is the express framework has updated and your code is a tad out of sync. Are you planning on providing any code updates for the changes in Express to latest?

( great book so far! )

cheers

Tj

I was once under the false impression that it didn't matter what value a constructor returned with used with new as in p = new Person()

But, I've told by the gurus at the node.js and coffee-script github sites that this is not so.

In general, with coffeescript it's best to use class as in: class Person ...

But, if one tries to create a function that acts as a constructor in CoffeeScript, there is at least one gotcha. The follow three short scripts demonstrate the problem, which apparently the writers of CoffeeScript and JavaScript will simply have to deal with. (The gurus who create/maintain these languages don't think its their problem and closed my bug report immediately.)

So, Mark, as someone who writes books on CoffeeScript, I hope the following might help you warn your readers. (BTW: like your book)

#--------------------------   person.coffee -----------------------------------

Person = (name) ->
    @name = name
    @greet_friend = (friend) ->
        console.log("Hello #{friend}. My name is #{@name}.")
    ###
    wierd CoffeeScript/Node.js error:
    You will get and error if you comment the next line out
    and explicitly return the greet_friend method above.
    ###
    return null



Person.prototype.hello_world =  ->
    console.log("#{@name} says hello world.")


p = new Person('Fred')
p.greet_friend('Mary')
p.hello_world()

#-------------------------   bad_person.coffee ---------------------
Person = (name) ->
    @name = name
    @greet_friend = (friend) ->
        console.log("Hello #{friend}. My name is #{@name}.")
    ###
    wierd CoffeeScript v1.6.1/Node.js v0.8.22 error:
    This will bomb because we've commented out
    the 'return null' line below, which means
    that CoffeeScript will explicitly return
    the greet_friend method above.

    return null
    ###

Person.prototype.hello_world =  ->
    console.log("#{@name} says hello world.")


p = new Person('Fred')
p.greet_friend('Mary')
p.hello_world()

#------------------- redeemed_bad_person.js -----------------------

// Generated by CoffeeScript 1.6.1 
// but modified by me. I removed the
// explicit return of the greet_friend
// method.

(function() {
  var Person, p;

  Person = function(name) {
    this.name = name;
    this.greet_friend = function(friend) {
      return console.log("Hello " + friend + ". My name is " + this.name + ".");
    };
    /*
        wierd CoffeeScript v1.6.1/Node.js v0.8.22 error:
        This version works because we do not
      explicitly return the greet_friend 
      method above.
    */

  };

  Person.prototype.hello_world = function() {
    return console.log("" + this.name + " says hello world.");
  };

  p = new Person('Fred');

  p.greet_friend('Mary');

  p.hello_world();

}).call(this);