Question

我正在尝试使用form_for帮助方法在rails中创建新记录。我认为params散列是空白的，因为我在提交表单时一直出现空白错误。

这是我的表格：

<% provide(:title, "Add Department") %>
<h1>Add Department</h1>

<div class="row">
    <div class="span6 offset3">
        <%= form_for(@department) do |f| %>
            <%= render 'shared/department_error_messages' %>

            <%= f.label :Full_Department_Title %>
            <%= f.text_field :full_name %>

            <%= f.label :Department_Abbreviation %>
            <%= f.text_field :abbreviation %>

            <%= f.submit "Add department", class: "btn btn-large btn-primary" %>
        <% end %>
    </div>
</div>

这是我的部门控制员

class DepartmentsController < ApplicationController
    def show
        @department = Department.find(params[:id])
    end

    def new
        @department = Department.new
    end

    def create
        @department = Department.new(params[department_params])     # Not the final implementation!
        if @department.save
            redirect_to root_path
        else
            render 'new'
        end
    end

    private

    def department_params
        # This says that params[:department] is required, but inside that, only params[:department][:full_name] and 
        # params[:department][:abbreviation] are permitted. Unpermitted params will be stripped out         

        params.require(:department).permit(:full_name, :abbreviation)
    end
end

这是模特：

class Department < ActiveRecord::Base
    validates :full_name, presence: true, length: { minimum: 6 }
end

当我提交时，会显示错误，说明full_name不能为空（并且字段现在为空）。调试信息是：

--- !ruby/hash:ActionController::Parameters utf8: ✓ 
authenticity_token: EjfYjWAzaw7YqVZAkCPZwiEMFfb2YLIRrHbH1CpZOwA= 
department: !ruby/hash:ActionController::Parameters   
full_name: Sports Department   
abbreviation: SD 
commit: Add department 
action: create 
controller: departments

我还检查了开发日志。事务开始然后回滚。我可以在控制台中保存一条记录，所以我猜它与params hash有关，但无法弄明白。请帮忙

Answer 1

这一行：

@department = Department.new(params[department_params])

应该是：

@department = Department.new(department_params)

而且，作为一个小问题（但不会导致此问题），您的标签标签应如下所示：

f.label :full_name, "Full Department Title"

这样他们就可以正确地与输入相关联。

使用params hash在rails 4.0中保存记录

1 个答案: