Backbone不会返回从后端发送的数据

Question

我正在尝试从骨干中的后端获取数据，虽然数据被返回到前端，但是成功函数根本没有执行，但是执行console.log（）on done会发出从后端获取的所有数据。

 var app = app || {};
    app.url = '/usernotes/';

    app.AboutModel = Backbone.Model.extend({
        url: function() {
            return app.url;
        },
        defaults: {
            about: 'No',
            editorNote: ''

        },
        set: function() {
          localStorage.setItem('about', JSON.stringify(this.toJSON()));
        }
    });

app.AboutView = Backbone.View.extend({
        el: '#aboutParent',

        events: {
            'click #yes': 'GetData',
            'click #no': 'Default',
            'click #custom': 'OpenEditor'
        },

        template: _.template($('#about').html()),

        initialize: function() {            
            this.render();
        },

        render: function() {
            this.$el.html(this.template, this);
        },

        Default: function() {
            this.model.set({
                about: 'No'
            });            
        },

        GetData: function() {            
            this.model = new app.AboutModel({});

            app.email = $('#data-user').text();
            app.username = $('#data-username').text();

            this.model.fetch({
                data: {
                    email: app.email,
                    username: app.username
                },
                type: 'POST',
                processData: true,
                success: function(data) {                                                         
                    $('.summernote .note-editable').html(data.attributes.about);
                },complete: function(xhr, textStatus) {
                    console.log(xhr);
                },
                error: function() {                                                   
                    $('.summernote .note-editable').html('');
                }

            });

        }

    });

这就是它在快递后端的外观

exports.find = function(req, res) {

if (req.body === null || req.body === undefined) {
    res.send(null);
} else {        
    req.app.db.models.UserNotes.findOne({
        email: req.body.email,
        username: req.body.username
    }, function(err, user) {
        if (err) {                
            res.send({
                "error": "The Email Does not exist in the database"
            });
        } else {                
            res.send(user);
        }
    });

}

};