Rails: flash notice unless only certain attributes updated

Question

I want to show a flash notice in my Rails app all the time unless only certain attributes are updated.

def update
  if @user.update_attributes(user_params)
    if user_params == [:user][:certain_params]
      redirect_to users_path
    else
      redirect_to users_path, notice: "#{@user.name} saved."
    end
  else
    redirect_to edit_user_path(@user), flash: { error: @user.mapped_errors }
  end
end

Something like this pseudocode?

I don't understand what you mean by "unless only"... are you saying that the user must change certain attributes? He's not allowed to leave them unchanged? — SteveTurczyn, Aug 28 '15 at 00:27
If only one particular attribute is changed, let's call it `photo`, I want to hide the flash message. Otherwise I want it shown. — t56k, Aug 28 '15 at 00:38
So if they change `photo` plus some other attribute, you want to see the message. If they don't change `photo` but they change some other attribute, you want to see the message. If they change `photo` but don't change anything else, you *don't* want to see the message. Is that right? — SteveTurczyn, Aug 28 '15 at 00:40
Do you need it exactly updated or are you trying to remind them to upload a photo so you want that shown if the photo is not uploaded? — dinomix, Aug 28 '15 at 00:50

score 2 · Accepted Answer · answered Aug 28 '15 at 00:58

2

Use the changed method to get an array of the attributes that are changed, create a flash message if the attributes are not the "non-notify" attributes.

def update
  @user.assign_attributes(user_params)
  changed_fields = @user.changed
  if @user.save
    flash[:notice] = "#{@user.name} saved." if changed_fields != ["photo"]
    redirect_to users_path 
  else
    redirect_to edit_user_path(@user), flash: { error: @user.mapped_errors }
  end
end

This will show the saved notice if they change photo plus other attributes, or if they change other attributes but not photo. The message is suppressed only if only photo is changed.

answered Aug 28 '15 at 00:58

SteveTurczyn

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Perfect! Thank-you so much. – t56k Aug 28 '15 at 01:02
I know this was not part of the question, yet I think worth noting: this is NOT working for NESTED ATTRIBUTED – Jeni Dec 30 '18 at 09:48
1

So add it to the changed_fields list... `changed_fields = (@user.changed + @user.name_of_nested_associations.map(&:changed)).flatten` – SteveTurczyn Dec 30 '18 at 13:15

score 0 · Answer 2 · edited May 23 '17 at 10:26

def update
    @user = User.find(params[:id])
    # lets say you have these attributes to be checked
    attrs = ["street1", "street2", "city", "state", "zipcode"]
    attributes_changed = (@user.changed & attrs).any?
  if @user.update_attributes(user_params)
    flash[:notice] = "#{@user.name} saved."  if attributes_changed
    redirect_to users_path
  else
    redirect_to edit_user_path(@user), flash: { error: @user.mapped_errors }
  end
end

For more info see
Rails 3 check if attribute changed
http://api.rubyonrails.org/classes/ActiveModel/Dirty.html

Rails: flash notice unless only certain attributes updated

2 Answers2