Question

I have a coffescript datastructure which consists of an object which has arrays of other objects, these objects have helper methods which make it easier to manipulate the data in the data structure:

class CrossData

  species_list: {
    species1: [21,10,30,40]
  }

  constructor: () ->
    @species = "defualt"
    @donors = [new CrossDonor] #array that will be full of CrossDonors

  helper_method: (arg1) =>
    #do stuff with crossdata

class CrossDonor
  constructor: () ->
    @name = "default"
    @linkage_group = -1
    @trait_cm = -1

  helper_method: (arg1) ->
    #do stuff with cross donor 

cross_data = new CrossData

if I try and upload this via jquery ajax ie:

$.ajaxSetup(
  beforeSend: (xhr) ->
    xhr.setRequestHeader('X-CSRF-Token',
    $('meta[name="csrf-token"]').attr('content')))

$.ajax(
  type: "POST",
  url: '/crosses/save',
  data: cross_data
  contentType: 'json'
  success: (msg) -> 
    alert( "Data Saved: " + msg )
)

it doesn’t work since it trips up over the functions, I guess the answer is to create a function which produces a json verison of the coffee script classes. I’m wondering if there is a jquery plugin which will give me a coffee_class data type?

Answer 1

One thing you could do that might help you in the future would be to add a toJSON method:

If an object being stringified has a property named toJSON whose value is a function, then the toJSON method customizes JSON stringification behavior: instead of the object being serialized, the value returned by the toJSON method when called will be serialized.

This is more or less like to_json in Rails. jQuery won’t call it automatically, unfortunately, but the JSON library will and so will Backbone (if you end up using Backbone); adding a toJSON method also allows the object to control its own serialization.

Then add a toJSON call to your $.ajax:

$.ajax(
  type: "POST"
  url: '/crosses/save'
  data: cross_data.toJSON()
  contentType: 'json'
  success: (msg) -> 
    alert( "Data Saved: " + msg )
)

Or, with recent jQuery’s, you could set up an AJAX pre-filter to automatically call toJSON when it is available:

$.ajaxPrefilter( (opts, original_opts) ->
    if(original_opts.data && original_opts.data.toJSON && $.isFunction(original_opts.data.toJSON)
        opts.data = $.param(original_opts.data.toJSON())
)

Then if you called $.ajax with a data that had a toJSON method, toJSON would get called to serialize the data object.

You could also set up a simple recursive $.ajaxPrefilter to automatically skip over anything in original_opts.data that $.isFunction detected as a function. You’d want to use $.isPlainObject to skip over data that is already a string though.

I don’t know of any plugins that do this automatically though.