Question

I am using a YML file to store trivial data.

I can create yml:

File.open("data.yml", "w") do |yaml|
    yaml.write(@some_hash.to_yaml)
end

And open yml:

path = File.expand_path(File.dirname(__FILE__))
@trivial_data = YAML.load_file("#{path}/../../../config/data.yml")

But I don’t know how to update a file. Say I want to add another row:

4: 
  agent_id: 332
  last: Wade
  first: Jason
  suffix: Sr
  rep_number: 2

How do I open, and update the yaml file? And is this a good idea on a production server?

Answer 1

Combine what you have and that’s what you should do:

path = File.expand_path(File.dirname(__FILE__))
trivial_data = YAML.load_file("#{path}/../../../config/data.yml")
# ... manipulate data ...
File.open("data.yml", "w") do |yaml|
  yaml.write(trivial_data.to_yaml)
end

You can’t add something to a file without writing to it. YaML is a serialization language, and it doesn’t make much sense to try and manipulate it directly. There is no simpler way (that I know of) that isn’t horribly prone to errors.