Create array from ActiveRecords Association CollectionProxy

Question

I have a Group model which has_many Topics. The Topics model has_many Posts. I want to create an array of all Topics for a Group sorted by the Post attribute :published_on.

On my Group show page I have @group.topics.collect {|x| x.posts } which returns an ActiveRecord::Associations::CollectionProxy array with each element containing an array of post objects.

[
[[topic1 post],[topic1 post],[topic1 post]],
[[topic2 post],[topic2 post],[topic2 post]],
[[topic3 post],[topic3 post],[topic3 post]],
]

How do I create a single array of posts sorted by :published_on ?

xlembouras · Accepted Answer · 2014-06-26 10:02:59Z

6

I think that

group.topics.includes(:posts).order("posts.published_on").map(&:posts).flatten

would be enough.

answered Jun 26, 2014 at 10:02

xlembouras

8,3254 gold badges35 silver badges44 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Mohamed El Mahallawy Over a year ago

Agree with this answer. I'd use .pluck(:posts) instead of .map

ogabriel · Accepted Answer · 2020-08-06 12:53:17Z

2

You can also resolve this with the correct relations.

On your Group model you could do something like:

# you already have this relation
has_many :topics
# you add this
has_many :posts, through: :topics

That through works using topics like a bridge for posts, and returning all posts that your group have.

And than, your query would look something like group.posts.order(:published_on)

answered Aug 6, 2020 at 12:53

ogabriel

3013 silver badges7 bronze badges

Collectives™ on Stack Overflow

Create array from ActiveRecords Association CollectionProxy

2 Answers 2

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related