Rails：如果check_box_tag中没有选择任何内容，则默认选择

Question

我有一个应用程序，用户可以将项目输入数据库。

有一个选项，他们可以为他们的项目选择许多不同的技术。目前，如果用户没有选择至少1种技术，应用程序会标记错误。

我想改变这个，所以如果他们不选择一项技术，它会自动下降为“其他”。

这里是我的项目负责人的行动，新的创造：

def new 
    @project = Project.new 
     @technol = Technol.new(params[:tech]) 

     @all_technols = Technol.order('tech ASC') 
     @all_technols = Technol.all 
     tech_ids = params[:technols][:id].reject(&:blank?) unless params[:technols].nil? 


     @project_technol = @project.projecttechnols.build 

    respond_to do |format| 
     format.html # new.html.erb 
     format.json { render json: @project } 
    end 
    end 



def create 
    @project = Project.new(params[:project]) 
     @project.client = params[:new_client] unless params[:new_client].blank? 
     @project.industry = params[:new_industry] unless params[:new_industry].blank? 
     @project.business_div = params[:new_business_div] unless params[:new_business_div].blank? 


if !params[:technols].nil? 

      params[:technols][:id].each do |tech| 


       if !tech.empty? 

        @project_technol = @project.projecttechnols.build(:technol_id => tech) 
        end 
      end 

end 

这里是该技术领域

<ul> 


<% @all_technols.each do |technol| %> 



<li class="split"> 
<%= check_box_tag "project[technol_ids][]", technol.id, @project.technols.include?(technol) %> 
<%= technol.tech %> 
</li> 

<% end %> 
</ul> 

技术ID，在 “其它” 的新观点技术表是“18”。那么有没有办法说，如果没有选择技术，那么:technol_id => ["18"]。

我得到的帮助较早，并建议我应该补充一点：

def create 
    ... 
    technol_ids = params[:technol_ids].blank? ? [18] : params[:technol_ids] 
    technol_ids.each do |id| 
    ... 
    end 
    ... 
end 

我无法得到这个工作。我认为我没有把它放在我的代码中。我还是个新手，因此请在尝试帮助时记住这一点。非常感谢

编辑

在没有technols_id选择

Processing by ProjectsController#create as HTML 
    Parameters: {"utf8"=>"Ô£ô", "authenticity_token"=>"8Hgc1GXqNhWkzO3Wgkfpf6z+fdImf6QvAv0XLbP0a5g=", "project"=>{"project 
_name"=>"Test", "archive"=>"0", "username"=>"test", "status"=>"Active", "exception_pm"=>"", "client"=>"", "business_d 
iv"=>"", "project_owner"=>"", "start_date"=>"11-12-2012", "first_name"=>"test", "last_name"=>"test", "fullname"=> 
"test test", "entry_date"=>"2012-11-26", "end_date"=>"19-12-2012", "techinfo"=>"Test", "role"=>"", "industry"=>"" 
, "summary"=>"Test", "lessons_learned"=>"Test", "customer_benefits"=>"Test", "financials"=>"£500,000 - £999,999 "}, "n 
ew_exception_pm"=>"Test", "new_client"=>"Test", "new_business_div"=>"Test", "new_project_owner"=>"Test", "new_role"=>"Te 
st", "new_industry"=>"Test", "commit"=>"Save New Project"} 

随着1 technols_id

Started POST "/projects" for 192.168.16.127 at 2012-11-26 16:47:27 +0000 
Processing by ProjectsController#create as HTML 
    Parameters: {"utf8"=>"Ô£ô", "authenticity_token"=>"8Hgc1GXqNhWkzO3Wgkfpf6z+fdImf6QvAv0XLbP0a5g=", "project"=>{"project 
_name"=>"Test", "archive"=>"0", "username"=>"Test", "status"=>"Active", "exception_pm"=>"", "client"=>"", "business_d 
iv"=>"", "project_owner"=>"", "start_date"=>"11-12-2012", "first_name"=>"Test", "last_name"=>"McLaughlin", "fullname"=> 
"Test Test", "entry_date"=>"2012-11-26", "end_date"=>"20-12-2012", "technol_ids"=>["1"], "techinfo"=>"Test", "rol 
e"=>"", "industry"=>"", "summary"=>"Test", "lessons_learned"=>"Test", "customer_benefits"=>"Test", "financials"=>"£250, 
000 - £499,999 "}, "new_exception_pm"=>"Test", "new_client"=>"Test", "new_business_div"=>"Test", "new_project_owner"=>" 
Test", "new_role"=>"Test", "new_industry"=>"Test", "commit"=>"Save New Project"} 

Answer 1

首先，该字段的名称应使用获取参数，像我的例子一样使用。 您正在收到一系列技术ID，对不对？因此，而不是使用，如果检查零，使用此：

params[:project][:technol_ids] ||= [18] 

，如果它是零它会变成这个参数到数组。

params[:project][:technol_ids].each do |tech_id| 
    @project_technol = @project.projecttechnols.build(:technol_id => tech) 
end