how to change one attribute (or a group of attributes) when another changes?

rubyonrails-talk
1

I have a hosts class with an ip_addresses class which has a host_id attribute. All hosts are associated with a data_center, and all ip_addresses are associated with a network. Networks have a standard IP network definition (192.168.59.0/24) etc. When a user changes that network definition, I need to go through all ip_addresses in the network and change them to agree with the new network definition. For example, if the network is defined as 192.168.59.0/24, and the user changes it to 10.168.59.0/24 in the networks form, I need to change all the ip_addresses in that network to match the new scheme. So I need to know when the network changes. How do I do this? Like, is there a way to add code to the function that sets the network definition?

2

Add an 'after_save' method to your Network model that checks to see what's changed and if appropriate goes through and changes all of it's IP_Address children...

-philip

3

I think you have redundant data in the db, as you are storing the ip address and the network definition, where much of the data is common between these two. I suggest not storing the full ip address, just the offset from that in the network definition, or something similar. Then your problem will go away.

Colin

4

Colin,

You’re right! But I can’t go down that path right now. In the future I’ll refactor the heck out of tis rats nest, but for now I have to make it work.

Jason

5

Jason Michael wrote:

Colin,

You're right! But I can't go down that path right now. In the future I'll refactor the heck out of tis rats nest, but for now I have to make it work.

Jason

If it's a "rats nest", it will probably be faster to refactor than to try to maintain it as it is.

Best,