Stupid TypeError while checking array values

Ruby
1

Not sure if I’m even close to the mark on this. Ruby noob here…RACKIN
M’BRAINS HERE!! :frowning:

I am trying to check values of an array against another value.
Unfortunately, I keep getting a TypeError that says:

can’t convert User into Integer

I am trying to check if a logged in user has access to a course id based
on ownership assignments.

I have 2 tables having M:M relationship and a join table:

  •          *
  • Courses *
  •          *

  •                *
  • Courses_Users *
  •                *

  •          *
  • Users *
  •          *

…and here is my action

def user_assigned_course(course_id, user_id)
allowed_users = Course.find_by_id(course_id).users
allowed_users.each do |user|
if allowed_users[user] == user_id
return true
end
end
end

…help…

2

Ooops: forgot to add “.id” after “allowed_users[user]”

…and here is my action

def user_assigned_course(course_id, user_id)
allowed_users = Course.find_by_id(course_id).users
allowed_users.each do |user|
if allowed_users[user] == user_id
return true
end
end
end

…help…

def user_assigned_course(course_id, user_id)
allowed_users = Course.find_by_id(course_id).users
allowed_users.each do |user|
if allowed_users[user].id == user_id
return true
end
end
end

3

…yet this didn’t fix the error, so still:

HELP! :confused:

4

1 def user_assigned_course(course_id, user_id)
2 allowed_users = Course.find_by_id(course_id).users
3 allowed_users.each do |user|
4 if allowed_users[user].id == user_id
5 return true
6 end
7 end
8 end

change line 4 to:
if user.id == user_id
user is not an index, it is an actual value.

BTW: you could also:

  1. write return true before if (replace lines 4-5 with):

return true if user.id == user_id

  1. use array function any? (replace lines 3-7 with):

return true if allowed_users.any? {|user| user.id == user_id }

probably you can even omit the ‘return true if’ part, so the whole
func could collapse to

def user_assigned_course(course_id, user_id)
Course.find_by_id(course_id).users.any? {|user| user.id == user_id }
end

although this might be too tight, as the left out ‘allowed_users’ adds
meaning to the .users array.

5

Rick A. wrote:

Ooops: forgot to add “.id” after “allowed_users[user]”

…and here is my action

def user_assigned_course(course_id, user_id)
allowed_users = Course.find_by_id(course_id).users
allowed_users.each do |user|
if allowed_users[user] == user_id
return true
end
end
end

…help…

def user_assigned_course(course_id, user_id)
allowed_users = Course.find_by_id(course_id).users
allowed_users.each do |user|
if allowed_users[user].id == user_id
return true
end
end
end

ooops blush

this worked:

def user_assigned_course(course_id, user_id)
allowed_users = Course.find_by_id(course_id).users
for user in allowed_users
if user.id == user_id
return true
end
end
end

6

Rick A. wrote:

def user_assigned_course(course_id, user_id)
allowed_users = Course.find_by_id(course_id).users
for user in allowed_users
if user.id == user_id
return true
end
end
end

And if you want to make your code a little bit cleaner, you can take
advantage of Ruby’s Enumerable#any? method:

def user_assigned_course(course_id, user_id)
Course.find_by_id(course_id).users.any? { |u| u.id == user_id }
end

Jamey

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7

On 10/9/06, Rick A. [email protected] wrote:

Wow, thanks guys! I better read up on making my Ruby code more
efficient…

You’re welcome. It really helps to browse the docs (e.g.
ruby-doc.orc/core) to see what’s in. Especially the Array, Hash,
String, Enumerable contain a lot of shortcuts.

J.

8

Wow, thanks guys! I better read up on making my Ruby code more
efficient…

Rick