My cloning method is stealing the children from the original model - ruby-on-rails

I have checked a bunch questions on this matter, including here, here, and here. I can't seem to figure out what is going wrong here.
Here is my copy method:
def copy(new_period)
copy = self.dup
copy.report_id = Report.maximum(:report_id).next
copy.period_id = new_period
copy.responses = self.responses.dup
copy.save
end
This method correctly makes a copy of the Report model and assigns it to the new period as expected. It also moves all the children from the original report to the new report without duplicating, which is not expected. I don't understand why this is happening.
Anyone have any ideas?

I believe the guilty is the following line
copy.responses = self.responses.dup
The returned value from self.responses is an ActiveRecord::Relation. When you call dup you are duplicating the relation instance, not the resources pointed by the scope.
If you want to duplicate the response objects you need to first load them.
copy.responses = self.responses.map { |response| response.dup }
or
copy.responses = self.responses.map(&:dup)

dup does a shallow copy. It does not copy all of its child objects as well. This is important to note with arrays and hashes as well.
The solution is to essentially write a clone method for your model:
def clone(new_period)
copy = self.class.new self.attributes.slice(*%w{attributes to copy})
copy.report_id = Report.maximum(:report_id).next
copy.period_id = new_period
copy.responses = Response.clone_multiple(self.responses)
copy.save
end
Likewise with the response, add a class method to clone a collection:
class << self
def clone_multiple(collection)
collection.map do |response|
copy = self.new(response.attributes.slice(*%w{attributes to clone})
copy.save
copy
end
end
end

Related

DRY way of assigning new object's values from an existing object's values

I created a class method that is called when a new object is created and copied from an old existing object. However, I only want to copy some of the values. Is there some sort of Ruby shorthand I can use to clean this up? It's not entirely necessary, just curious to know if something like this exists?
Here is the method I want to DRY up:
def set_message_settings_from_existing existing
self.can_message = existing.can_message
self.current_format = existing.current_format
self.send_initial_message = existing.send_initial_message
self.send_alert = existing.send_alert
self.location = existing.location
end
Obviously this works perfectly fine, but to me looks a little ugly. Is there any way to clean this up? If I wanted to copy over every value that would be easy enough, but because I only want to copy these 5 (out of 20 something) values, I decided to do it this way.
def set_message_settings_from_existing(existing)
[:can_message, :current_format, :send_initial_message, :send_alert, :location].each do |attribute|
self.send("#{attribute}=", existing.send(attribute))
end
end
Or
def set_message_settings_from_existing(existing)
self.attributes = existing.attributes.slice('can_message', 'current_format', 'send_initial_message', 'send_alert', 'location')
end
a hash might be cleaner:
def set_message_settings_from_existing existing
fields = {
can_message: existing.can_message,
current_format: existing.current_format,
send_initial_message: existing.send_initial_message,
send_alert: existing.send_alert,
location: existing.location
}
self.attributes = fields
end
you can take this further by only selecting the attributes you want:
def set_message_settings_from_existing existing
fields = existing.attributes.slice(
:can_message,
:current_format,
:send_initial_message,
:send_alert,
:location
)
self.attributes = fields
end
at this point you could also have these fields defined somewhere, eg:
SUB_SET_OF_FIELDS = [:can_message, :current_format, :send_initial_message, :send_alert, :location]
and use that for your filter instance.attributes.slice(SUB_SET_OF_FIELDS)

Getting "original" object during a before_add callback in ActiveRecord (Rails 7)

I'm in the process of updating a project to use Ruby 3 and Rails 7. I'm running into a problem with some code that was working before, but isn't now. Here's (I think) the relevant parts of the code.
class Dataset < ActiveRecord::Base
has_and_belongs_to_many :tags, :autosave => true,
:before_add => ->(owner, change){ owner.send(:on_flag_changes, :before_add, change) }
before_save :summarize_changes
def on_flag_changes(method, tag)
before = tags.map(&:id)
after = before + [tag.id]
record_change('tags', before, after)
end
def record_change(field, before_val, after_val)
reset_changes
before_val = #change_hash[field][0] if #change_hash[field]
if before_val.class_method_defined? :sort
before_val = before_val.sort unless before_val.blank?
after_val = after_val.sort unless after_val.blank?
end
#change_hash[field] = [before_val, after_val]
end
reset_changes
if #change_hash.nil?
#change_notes = {}
#change_hash = {
tags: [tags.map(&:id), :undefined]
}
end
end
def has_changes_to_save?
super || !change_hash.reject { |_, v| v[1] == :undefined }.blank?
end
def changes_to_save
super.merge(change_hash.reject { |_, v| v[0] == v[1] || v[1] == :undefined })
end
def summarize_changes
critical_fields = %w[ tags ]
#change_notes = changes_to_save.keep_if { |key, _value| critical_fields.include? key } if has_changes_to_save?
self.critical_change = true unless #change_notes.blank?
end
There are more fields for this class, and some attr_accessors but the reason I'm doing it this way is because the tags list can change, which may not necessarily trigger a change in the default "changes_to_save" list. This will allow us to track if the tags have changed, and set the "critical_change" flag (also part of Dataset) if they do.
In previous Rails instances, this worked fine. But since the upgrade, it's failing. What I'm finding is that the owner passed into the :before_add callback is NOT the same object as the one being passed into the before_save callback. This means that in the summarize_changes method, it's not seeing the changes to the #change_hash, so it's never setting the critical_change flag like it should.
I'm not sure what changed between Rails 6 and 7 to cause this, but I'm trying to find a way to get this to work properly; IE, if something says dataset.tags = [tag1, tag2], when tag1 was previously the only association, then dataset.save should result in the critical_change flag being set.
I hope that makes sense. I'm hoping this is something that is an easy fix, but so far my looking through the Rails 7 documentations has not given me the information I need. (it may go without saying that #change_notes and #change_hash are NOT persisted in the database; they are there just to track changes prior to saving to know if the critical_change flag should be set.
Thanks!
Turns out in my case there was some weird caching going on; I'd forgotten to mention an "after_initialize" callback that was calling the reset method, but for some reason at the time it makes this call, it wasn't the same object as actually got loaded, but some association caching was going on with tags (it was loading the tags association with the "initialized" record, and it was being cached with the "final" record, so it was confusing some of the code).
Removing the tags bit from the reset method, and having it initialize the tag state the first time it tries to modify tags solved the problem. Not particularly fond of the solution, but it works, and that's what I needed for now.

Rails - submitting JSONs to database from controller

I am working on a Rails app, and I am attempting to insert attributes from JSONs as database entries. I'm running into a problem, though, and would appreciate some guidance.
I've been able to jam a few things together and come up with something that sort of works...
def create
#report_group = Array.new
#report_group.push({location:"home", comments:"Hello, database!"}, {location:"away", comments:"Goodbye, database!"})
#report_group.each do |x|
#new_report = Report.new(x)
#new_report.user_id = current_user.id
#new_report.save
end
end
private
def report_params(params)
params.permit(:user_id,:location,:comments)
end
This is a good first step - this commits two entries to my database, one for each of the hashes pushed into #report_group, but it is suffering from a problem - the create action does not reference the report_params whitelist.
I have built several Rails apps where entries are submitted one at a time via the standard Rails form helpers, but I have never done it with multiple JSONs like this before. Trying out the syntax I'd use in a typical form helper situation
#new_report = Report.new(report_params(x))
throws the expectable error undefined method permit' for #<Hash:0x007f966b35e270> but I am not sure what else to do here.
EDIT TO SHOW SOLUTION
Big thanks to #oreoluwa for pointing me in the right direction. Here's the solution that I came up with.
def create
#report_group = Array.new
#report_group.push({location:"home", comments:"Hello, database!"}, {location:"away", comments:"Goodbye, database!"})
#report_group.each do |x|
hash = ActionController::Parameters.new(x)
#new_report = Report.new(report_params(hash))
#new_report.user_id = current_user.id
#new_report.save
end
end
private
def report_params(params)
params.permit(:user_id,:location,:comments)
end
You're getting the error because a Hash is not the same as an ActionController::Parameters. In order to use the permit method with your Hash you may need to first convert it to ActionController::Parameters, as such:
hash = {location:"home", comments:"Hello, database!"}
parameter = ActionController::Parameters.new(hash)
parameter.permit(:user_id,:location,:comments)
I don't know if that is what you're looking for, but I thought to point you in the right direction.

Spree error when using decorator with the original code

Need a little help over here :-)
I'm trying to extend the Order class using a decorator, but I get an error back, even when I use the exactly same code from source. For example:
order_decorator.rb (the method is exactly like the source, I'm just using a decorator)
Spree::Order.class_eval do
def update_from_params(params, permitted_params, request_env = {})
success = false
#updating_params = params
run_callbacks :updating_from_params do
attributes = #updating_params[:order] ? #updating_params[:order].permit(permitted_params).delete_if { |k,v| v.nil? } : {}
# Set existing card after setting permitted parameters because
# rails would slice parameters containg ruby objects, apparently
existing_card_id = #updating_params[:order] ? #updating_params[:order][:existing_card] : nil
if existing_card_id.present?
credit_card = CreditCard.find existing_card_id
if credit_card.user_id != self.user_id || credit_card.user_id.blank?
raise Core::GatewayError.new Spree.t(:invalid_credit_card)
end
credit_card.verification_value = params[:cvc_confirm] if params[:cvc_confirm].present?
attributes[:payments_attributes].first[:source] = credit_card
attributes[:payments_attributes].first[:payment_method_id] = credit_card.payment_method_id
attributes[:payments_attributes].first.delete :source_attributes
end
if attributes[:payments_attributes]
attributes[:payments_attributes].first[:request_env] = request_env
end
success = self.update_attributes(attributes)
set_shipments_cost if self.shipments.any?
end
#updating_params = nil
success
end
end
When I run this code, spree never finds #updating_params[:order][:existing_card], even when I select an existing card. Because of that, I can never complete the transaction using a pre-existent card and bogus gateway(gives me empty blanks errors instead).
I tried to bind the method in order_decorator.rb using pry and noticed that the [:existing_card] is actuality at #updating_params' level and not at #updating_params[:order]'s level.
When I delete the decorator, the original code just works fine.
Could somebody explain to me what is wrong with my code?
Thanks,
The method you want to redefine is not really the method of the Order class. It is the method that are mixed by Checkout module within the Order class.
You can see it here: https://github.com/spree/spree/blob/master/core/app/models/spree/order/checkout.rb
Try to do what you want this way:
Create file app/models/spree/order/checkout.rb with code
Spree::Order::Checkout.class_eval do
def self.included(klass)
super
klass.class_eval do
def update_from_params(params, permitted_params, request_env = {})
...
...
...
end
end
end
end

Woking with Packed Arrays, accessing data

I'm working with a large image array, so i've packed it. To access the pixels in the array i've implemented two methods.
def get_p(a)
data=a.unpack('S9s')
end
def put_p(array,index_a,value)
index=index_a[0]
k=array.unpack('S9s')
k[index]=value
k.pack('S9s')
end
It works, but i wondered if there was a more elegant way to do this. Makes my code look different than my standard array functions.
If get_p(image_data[i][j+1])[BLOB]==0
vs
if image_data[i][j+1][BLOB]==0
Also, don't know if anyone cares, but unpack doesn't seem to be documented anywhere, i was lucky to find a reference here, but it took some time.
You could craete a class like:
class PackedArray
def initialize(array)
#packed_array = array.pack('S9s')
end
def [](key)
data = #packed_array.unpack('S9s')
data[key]
end
def []=(key, val)
k = #packed_array.unpack('S9s')
k[key]=val
#packed_array = k.pack('S9s')
end
end
Then, fill your image_data[i][j] with an instance of this class. E.g.
for i in [0..image_data.size]
for j in [0..image_data[i].size]
image_data[i][j] = new PackedArray(image_data[i][j])
end
end
And finally you can simply use:
if image_data[i][j+1][BLOB] == 0
Without needing of packing/unpacking manually.

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