This relationship doesn't allow for me to create posts through a user object

Question

I need help fixing this relationship in Rails 4.1,

User Model Relationship

has_and_belongs_to_many :blogs, join_table: 'blogs_users'
has_many :posts, through: :blogs

Blog Model Relationship

has_many :posts

Post Model Relationship

belongs_to :blog
belongs_to :user

Issue?

The following, in rails c, works - how ever the user id is not passed in:

User.find_by_x(x).blogs.find_by_x(x).post.create(x)

The post is created for a user who has said blog attached, but because of how this type of chaining works, only the blog_id is passed to the post and not the user_id Its crucial I have both blog and user id.

So I thought, why not just create the post through the user object and pass in the blog id.

User.find_by_x(x).posts.create(x, blog_id: y) # Where y represents a blog the user is associated with.

Well that's all good and stuff accept I get this error:

ActiveRecord::HasManyThroughNestedAssociationsAreReadonly: Cannot modify association 'User#posts' because it goes through more than one other association.

I believe the issue is the fact that I have a join table and I am saying has_many :posts, through: blogs Most people might assume that "just remove the through part." How ever I need this type of relationship where a user can have many blogs and blogs can belong to many users and posts belongs to a blog and to a user but a user can have many posts ....

So is there a way to fix this to keep my concept or ...

Answer 1

The correct solution to this issue is a couple of things, one I needed to make sure that the realtionship between blog and user was the same as user and blog so in the blogs model I added:

has_and_belongs_to_many :users, join_table: 'blogs_users'

Then I needed to create posts at a post level, not a user level. So instead of, @user.posts.create() I need to do Post.create(blog_id: x, user_id: x) and then @user.posts will work properly (assuming the user has 2 blogs with one post in each you'll get back both posts)

Answer 2

the way you are creating posts does not make much sense.

this would be the usual way of doing it:

blog = current_user.blogs.find(params[:blog_id])
post = blog.posts.create(params[:post])

respond_with(post)