Accessing has_many objects

Rails
1

I have a the following models

CLIENT - has_many -> CAMPAIGNS - has_many -> CODES -> has_many ->HITS

So obviously a client has many codes, but each is linked to a
campaign. Now I have managed to get all the codes by using

has_many :codes, :through=>:campaigns

so the model looks like this

class Client < User
has_many :campaigns
has_many :codes, :through=>:campaigns

Now is it possible to make the client have many hits, which would
encompass all hits on all codes over all campaigns. Or Do I have to
loop through every campaign and every code and every hit to find all
the hits for a client.

2

Try :

has_many :codes, :through=>:campaigns, :include => :hits

then

client.codes.map(&:hits).inject(&:+)

On 8/3/07, Iain A. [email protected] wrote:

so the model looks like this

–
Cheers!

3

Actually, that’d depend on what’s exactly inside yout Hit model.

On 8/3/07, Pratik [email protected] wrote:

I have a the following models
class Client < User

–
Cheers!

–
Cheers!

4

My hit model has a month, a year and a hit count, and obv a code_id.

what does client.codes.map(&:hits).inject(&:+) do? i.e the
map(&:hits).inject(&:+)

5

Ah. Try :

In client.rb :
has_many :codes, :through=>:campaigns, :include => :hits

def hits
self.codes.map(&:hits).flatten.map(&:hit_count).inject(&:+)
end

Then for example :
client = Client.find(:first).hits

Explaination of
“self.codes.map(&:hits).flatten.map(&:hit_count).inject(&:+)” do :

  • self.codes will get you all associatied codes.
  • .map(&:hits) will return array of associatiated hits with codes.
    It’ll be an array of array. So we use .flatten
  • map(&:hit_count) will return array of hit_count from all Hit objects
    in the array
  • inject(&:+) is just a fancy way to do sum.

e.g. [1,2,3].inject(&:+) => 6

On 8/3/07, Iain A. [email protected] wrote:

On 8/3/07, Iain A. [email protected] wrote:

so the model looks like this
–

–
Cheers!

6

That sounds great. Thanks Alot.