Potential Validations syntax

gistfile1.js

  // A complete example.
  var Post = Backbone.Model.extend({
    validations: {
      body: {
        required: true, // Uses the built in validation methods
        minLength: 100
      },
      title: {
        // Pass multiple arguments to the validation function
        lengthInRange: [10,100],
        // Pass custom validation functions. Push errors into an array, Rails style.
        capitalized: function(attr, errors) {
          var c = attr.substr(0,1); 
          if(c !== c.toUpperCase()) {
            errors.push("Capitalize the title properly please!");
          }
        },
        // Overrride default error messages using last argument convention.
        required: [true, "You can't have a post without a title, this custom but informative message says so!"]
      },
      // Author attribute just has one custon validation.
      author: function(author, errors) {
        if(!author.canPublish()) {
          errors.push("Please publish this post as an author who is able to publish.");
        }
      },
      // Whole model has validations, 'base' is a reserved attribute.
      base: function(attrs, errors) {
        if(!stars.aligned()) {
          errors.push("A message about the whole model being invalid.");
        }
      }
    }
  });

  // In progress implementation at http://github.com/hornairs/backbone
  // Please leave feedback!