ruby-on-rails - Rails has_many 更新为空数组

Question

有如下表单代码:

= form_for @task, html: { class: 'form-horizontal' } do |f|
  .form-group
    .col-sm-9.col-sm-offset-3
      = render partial: 'shared/form_errors', locals: { subject: @task }
  .form-group
    label.col-sm-3.control-label for='title' Title
    .col-sm-9
      = f.text_field :title, class: 'form-control', placeholder: 'Title'
  .form-group
    label.col-sm-3.control-label for='description' Description
    .col-sm-9
      = f.text_area :description, class: 'form-control', placeholder: 'Description'
  .form-group
    label.col-sm-3.control-label Teams
    .col-sm-9
      ul
        - Team.all.each do |t|
          li
            = check_box_tag "team_ids", t.id, @task.teams.include?(t), name: 'task[team_ids][]'
            = t.name
  .form-group
    .col-sm-9.col-sm-offset-3
      = f.submit 'Save', class: 'btn btn-success'

如您所见，我可以通过复选框为我的任务选择团队。我的 Controller :

  def update
    @task = Task.find(params[:id])
    if @task.update(task_params)
      redirect_to tasks_path, flash: { alert: TASK_UPDATING_MESSAGE }
    else
      render 'edit'
    end
  end

  private
    def task_params
      params.require(:task).permit(:title, :description, team_ids: [])
    end

如果我更新一些选中的团队的任务，效果会很好；但我也希望能够检查任何团队并使用空的团队更新任务。但是在这种情况下 tasks_params 没有 team_ids 数组，并且更新不起作用。我该如何解决？谢谢!

Answer 1

我的理解是，当您提交表单时没有任何检查，您有 params[:task][:team_ids] = nil。

你可以试试这样的:

def task_params
  params[:task][:team_ids] = [] if params[:task][:team_ids].nil?
  params.require(:task).permit(:title, :description, team_ids: [])
end