tmp delete from activerecord

rubyonrails-talk
1

Hello,

This is the case: A project has many users. a project has an admin.

when I list the project users I don't want to display the admin user so what I tried was:

users = @project.users users.delete(admin_user)

users.each { |u| { ... }

but what happens is that the admin_user gets deleted from the project. is there a way to do a temporary delete without activerecord acting upon it and without having to check with an 'if' inside the for loop?

thanks

2

in your table you must have an field, that defines the role of the user. either an bool flag like is_admin, that can be true or false or a integer or string, with several states like admin, customer and so on.

with a is_admin flag: users = @project.users.find_by_is_admin(false)

with an integer role (0=normal user, 1 = admin) users = @project.users.find_by_role(0)

with a string role ("admin" = admin, "user" = user...) users = @project.users.find_by_role("user")

3

Very strange, as this should work just fine. I too would expect this to perform an Array#delete, not an ActiveRecord::Base.delete, and testing this in one of my projects worked fine.

Can you verify that the result of @project.users is indeed an array?

Jan

4

hm, i see. you want to use the array delete function. i'm not sure, how you could get the "old" one that was overwritten by ActiveRecord.

maybe you could use delete_if, as far as i know that's not recycled by Rails.

users.delete_if {|u| u == admin_user }

but since it has to go through the whole array and check every single item, you could do it in the loop, as far as performance is concerned.

5

Hello Jan,

Thanks for the reply.

@project.users.class says it is an Array.

when I don't do the 'delete' then the admin user does not get removed so this shouldn't be a problem in another part of my code.

strange indeed

6

It's not an array, it's an association proxy.

u = @project.users u.delete(foo)

is the same as @projects.users.delete(foo) (indeed there would be some very funky going on if it wasn't).

In this case you could do something like users_without_admin = @project.users.reject {|u| u == admin} or of course arrange for admin not to be in @project.users in the first place.

Fred

7

Jiminy, I didn't know that. And of course I tested it with a regular finder, not with an association .. my bad.

Thanks Fred!

8

with a is_admin flag: users = @project.users.find_by_is_admin(false)

find_all_by_is_admin!