chef

https://github.com/opscode/chef

Ruby

A systems integration framework, built to bring the benefits of configuration management to your entire infrastructure.

Chef::Property#is_set?

Find out whether this property has been set.

This will be true if:
- The user explicitly set the value
- The property has a default, and the value was retrieved.

From this point of view, it is worth looking at this as "what does the
user think this value should be." In order words, if the user grabbed
the value, even if it was a default, they probably based calculations on
it. If they based calculations on it and the value changes, the rest of
the world gets inconsistent.

Source | Google | Stack overflow

Edit

git clone [email protected]:opscode/chef.git
cd chef
open lib/chef/property.rb

Contribute

# Make a new branch

git checkout -b -your-name--update-docs-Chef--Property-is_set--for-pr

# Commit to git

git add lib/chef/property.rbgit commit -m "better docs for Chef::Property#is_set?"

# Open pull request

gem install hub # on a mac you can `brew install hub`

hub fork

git push <your name> -your-name--update-docs-Chef--Property-is_set--for-pr

hub pull-request

# Celebrate!