我有两种方法来过滤集合：

方法1：当我将其传递给视图时，使用此方法失败。

byCategory = @projects.byCategory(data)

方法2：此方法效果很好。

byCategory = new App.Collections.Projects(@projects.byCategory(data))

当我按byCategory映射并获得标题时，这两种方法均适用：

byCategory.map (project) ->
  console.log project.get('title')

当我将其传递给视图时，第二种方法有效。但是第一种方法失败了：

view = new App.Views.ProjectsCarousel(collection: byCategory)
$('.slides').html(view.render().el);

我的问题是：为什么？为什么第一个传递给视图时会失败，第二个为什么会起作用？第一个产生错误日志：TypeError: _ref is undefined

完整代码在这里：

路由器

class App.Routers.PortfolioRouter extends Backbone.Router
  routes:
    '': 'index'

  index: ->
    controls = new App.Views.ProjectsControls({el: '#list', projects: new App.Collections.Projects()});

收藏

class App.Collections.Projects extends Backbone.Collection
  url: '/de/projects'

  byCategory: (cat) ->
    return @where category: cat

观看次数

class App.Views.ProjectsControls extends Backbone.View

  events:
    'click a': 'selectCategory'

  initialize: (options) ->
    @projects = options.projects
    @projects.fetch()

  selectCategory: (event) ->
    event.preventDefault()

    data = $(event.currentTarget).attr('data-category')
    # This method fails when I pass it to the view
    # byCategory = @projects.byCategory(data)
    # This method works very well, why does it work and the previous no?
    byCategory = new App.Collections.Projects(@projects.byCategory(data))

    # it works with both methods
    byCategory.map (project) ->
      console.log project.get('title')

    view = new App.Views.ProjectsCarousel(collection: @projects)
    $('.slides').html(view.render().el);    



class App.Views.ProjectsCarousel extends Backbone.View
  template: JST['projects/carousel']

  render: ->
    @$el.html(@template(projects: @collection))
    this

模板

<% for project in @projects.models: %>
  <%= project.get('title') %>
<% end %>