仅在属性更改时更新User的属性

The original, happily working version of my project looked like this:

我项目的原始，愉快工作版本看起来像这样：

1) User fills out form (new action) and hits submit (create action)

1）用户填写表格（新动作）并点击提交（创建动作）

2) User is redirected to their edit page (edit action uses an edit_id created by model, not Rails auto-gen id), which shows the info user had already submitted

2）用户被重定向到他们的编辑页面（编辑操作使用由模型创建的edit_id，而不是Rails自动生成ID），这显示用户已经提交的信息

3) User can choose to change info (update action) and re-submit

3）用户可以选择更改信息（更新操作）并重新提交

In this version, even if the user changes nothing in the edit page and submits, the page will still flash a success alert.

在此版本中，即使用户在编辑页面中没有任何更改并提交，页面仍将闪烁成功警报。

From a database perspective, I don’t really care, because since the form is prefilled with the user’s info, the update_attributes method is just overriding old info with the same info.

从数据库的角度来看，我并不在意，因为表单预先填充了用户的信息，update_attributes方法只是用相同的信息覆盖旧信息。

From a user perspective though, it's annoying, so I want to ensure that the info is only updated and the success alert flashed only if the user actually changes something.

从用户的角度来看，它很烦人，所以我想确保只更新信息，并且只有当用户实际更改某些内容时才会闪烁成功警报。

I thought this would be really easy, changing the old code from this:

我认为这很容易，改变旧的代码：

def update
  @request = Request.find_by_edit_id(params[:edit_id])
  if @request.update_attributes(request_params) 
    flash[:success] = true
    redirect_to edit_request_path(@request.edit_id)
  else
    render 'edit'
  end
end

And adding one additional component to the "if" like this:

并在“if”中添加一个额外的组件，如下所示：

def update
  @request = Request.find_by_edit_id(params[:edit_id])
  if @request.update_attributes(request_params) && @request.changed?
    flash[:success] = true
    redirect_to edit_request_path(@request.edit_id)
  else
    render 'edit'
  end
end

But this doesn’t work. Now what happens is that, on the edit page, if I don’t change any info and hit submit, nothing happens (which is great), but if I DO change info and hit submit, still nothing happens (which is bad). What am I doing wrong?

但这不起作用。现在发生的是，在编辑页面上，如果我没有更改任何信息并点击提交，没有任何事情发生（这很好），但如果我改变信息并点击提交，仍然没有任何事情发生（这是不好的）。我究竟做错了什么？

Note: I initially thought it was an order of operations error, so I made it a nested if, with first if @request.update_attributes, and second if @request.changed, but this didn't work either...

注意：我最初认为这是一个操作错误的顺序，所以我把它作为嵌套if，首先是if @ request.update_attributes，第二个if @ request.changed，但是这个也不起作用......

1 个解决方案

#1

The update_attributes method includes the 'save' call as part of its method and is returning true if the save is successful. I think you're looking for something like this using assign_attributes:

update_attributes方法包含“save”调用作为其方法的一部分，如果保存成功则返回true。我认为你正在使用assign_attributes寻找这样的东西：

def update
  @request = Request.find_by_edit_id(params[:edit_id])
  @request.assign_attributes(request_params)

  if @request.changed?
    if @request.save
      flash[:success] = true
      redirect_to edit_request_path(@request.edit_id)
    else
      render 'edit'
    end
  else
    # Action if no change has been made
  end
end