gistfile1.rb

  # Create or update a particular user.
  #
  #   PUT /users/:permalink.html
  #   PUT /users/:permalink.json
  #   PUT /users/:permalink.xml
  #
  # If the user does not already exist, it will be created at the given URI.
  # If the user already exists, it will be updated. If the permalink is 
  # updated, the URI of the resource will have changed, and a Location: header
  # will be returned with the location of the new resource.
  def update
    @user = User.find_or_initialize_by_permalink(params[:permalink])
    @user.attributes = params[:user]
    new_record = @user.new_record?
    permalink_changed = @user.changed.include?('permalink') && !new_record
    success = @user.save
    respond_to do |format|
      format.html do
        if success
          saved = new_record ? 'created' : 'updated'
          flash[:success] = "User was successfully #{saved}."
          redirect_to @user
        else
          render :action => :new
        end
      end
      format.json do
        if success
          if new_record
            render :json => @user, :status => :created
          else
            render :json => @user, :status => :ok
            if permalink_changed
              headers['Location'] = user_path(@user)
            end
          end
        else
          render :json => @user.errors, :status => :unprocessable_entity
        end
      end
      format.xml do
        if success
          if new_record
            render :xml => @user, :status => :created
          else
            render :xml => @user, :status => :ok
            if permalink_changed
              headers['Location'] = user_path(@user)
            end
          end
        else
          render :xml => @user.errors, :status => :unprocessable_entity
        end
      end
    end
  end