If you don’t know what is a sitemap, I strongly encourage you to fill this gap in knowledge first and then get back to reading.
It seems to be clear that manual updating a sitemap can turn into a horror. Hopefully we can make the Rails do the job for us.
So, what components are we going to need to build a dynamic sitemap? Well, we are going to need a separate action (or even controller), an XML view and model methods to provide us with URL data.
Sometimes we want part of the website to be available to specific users only. Either we don’t want our users to interact with a piece of functionality we are still working on or we want to show the new function to our client first, before making it available to the public. In both cases, we can’t let a single unwanted user to slip through our fingers.
The first idea that crosses developer’s mind in such a situation is creating an authentication system based on the session.
Rails ActiveRecord is a quite useful piece of software, though it lacks some features and way of achieving the desired result is not always obvious.
Let’s assume that we have two tables in our database: categories and posts. We would like to get most essential categories; i.e. those having at least 10 posts assigned to them. We can achieve this using the SQL JOIN, GROUP BY and HAVING clauses. However, there is no :having parameter on the find() method’s parameter list.