Ruby on Rails-参数上的禁止属性？

Question

Im trying to redirect someone after they click a button and I keep getting the following error:

ActiveModel::ForbiddenAttributesError

Extracted source (around line #20):

It is throwing the error on the @post = Post.new line.

def create   
@post = Post.new(params[:post])

if @post.save
 redirect_to posts_path, :notice => "Your post was saved"

I am very new to Ruby and at the moment I am very confused of what this means. I am just following a tutorial and mine isnt working. If anyone could help that would be awesome :D

Answer 1

@post = Post.new(params[:post]) 

... is no longer used in the latest versions of rails. The problem is that it provided weak security. Someone who was updating their user profile (for example) could theoretically insert an attribute like "administrator: true" to change themselves into an administrator (if that's how admin flag is stored)

Strong parameters now require that you explicity specify which attributes you want to allow to be entered.

So nowadays we do...

@post = Post.new(post_params)

And we have a method later in the controller that specifies the permitted attributes, and looks like...

def post_params
  params.require(:post).permit(:title, :body)
end

Answer 2

While I don't have quite enough of your code to specifically answer the question, I can probably get pretty close (minus some column/attribute naming). With strong_params now the standard for Rails applications, you'd probably be looking to do something more like:

def create   
  @post = Post.new(post_params)

  if @post.save
    redirect_to posts_path, :notice => "Your post was saved"
  else
    #other stuff here
  end
end

private
def post_params
  params.require(:post).permit(:content, ....etc) #I took a guess at the attributes you are passing through your params on the create.
end

For a little extra easy-reading on the history/reason: http://blog.8thlight.com/will-warner/2014/04/05/strong-parameters-in-rails.html

Let me know if you'd like any additional clarification.