Add Document#cache_key for ActionView::Helpers::CacheHelper#cache

[seivan]

This is usually called inside a cache() block on the view
<% cache(@Profile) do %>

Will append different values on the plural model name if
new_record? - will append /new
updated_at - will append /id-updated_at.to_s(:number)
No timestamps - will append /id

[seivan]

I was wondering if the user would like to use other time fields as the cache key.

Possible solutions:

• Pass an array with other Time fields and pick max()
• Leave it as it is, and let the user override cache_key themselves with whatever they want.

[nviennot]

Hi Seivan :)

Few comments:

1. Let's put that method in the PrimaryKey module.

2. Let's use self.class.table_name instead of self.class.model_name.cache_key. Since the table name is configurable, two model with the same id with different table_names should not share the same cache key

3. updated_at.to_i and updated_at.utc.to_iyield the same values, so you can remove .utc.

4. The distinction with .new_record? doesn't seem useful as we always have an id, even before the record is created (unlike ActiveRecord).

5. The convention for key separator is to use : in NoBrainer, as it seems to be the standard with redis.

So how about we use something like this:

  def cache_key
    if updated_at = _read_attribute(:updated_at)
      "#{self.class.table_name}:#{pk_value}-#{updated_at.to_i}"
    else
      "#{self.class.table_name}:#{pk_value}"
    end
  end

Thanks for the pull request :)

Nico

[seivan]

@nviennot Amazing feedback, I appreciate it. I'll update shortly!

[nviennot]

I've ended up implementing the feature with little code, but I've maintained your authorship on the commit due to the initial work :)

Thanks,
Nico.

[seivan]

@nviennot No worries, but uhm I actually found a couple of things about your feedback that isn't valid. You're still interested, or we're done here?

[nviennot]

Yes please!! (I am interested)
Btw, if you look at the implementation, it's different from my initial feedback.