HistoryFile

Behaves like a File class and does some convenience stuff around a HistoryFile::FileDelegator instance. It lets you version files by dates. A date prefix is added to the file name.

If you want to write a file to store data from yesterday, you could write:

> f = HistoryFile[1.day.ago].new("/tmp/foo.txt", "w")
=> #<File:/tmp/2012.11.02-foo.txt>

The returned HistoryFile::FileDelegator object supports all methods that File has, but adds a date prefix to those methods that revolve around a single file (reading, writing, etc.)

If a file for a given date is not available, HistoryFile falls back to the freshest file that is older than the given date.

> f = HistoryFile[3.days.ago].new("test.txt", "w")
=> #<File:./2012.11.12-test.txt>
> f.write("I am old")
=> 8
> f.close
=> nil
> HistoryFile[Date.today].read("test.txt")
=> "I am old"
> HistoryFile[10.days.ago].read("test.txt")
Errno::ENOENT: No such file or directory - ./2012.11.05-test.txt

It does this for every method where a prefix is added and when an Errno::ENOENT is thrown.

You can pass an arbitrary amount of arguments to these methods, but all of them are file names. So we'll go ahead and prefix all of them:

• delete
• unlink
• safe_unlink

These are mostly methods that are either not HistoryFile specific (i.e. File.join to join components with the OS dependant path separator) or where one can't dumbly prefix filenames.

• absolute_path
• basename
• catname
• chmod
• chown
• compare
• copy
• directory?
• dirname
• expand_path
• extname
• fnmatch
• fnmatch?
• identical?
• install
• join
• lchown
• link
• makedirs
• move
• path
• realdirpath
• realpath
• rename
• split
• umask
• utime

All methods not mentioned in the previous two sections

If you set HistoryFile.mode = :subdir and you call one of the following methods, Historyfile will create a sub directory for the given date if it does not exist already

• new
• open

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