Some things I have loved so far about working with rake/ruby:

• File enumeration
• Blending regular expressions where it makes things more readable
• Testability

After checking out lots of other rake files, it is easy to see how much simpler ruby can make things. Along the way I am picking up some idiom’s that (seem) more acceptable and concise.

File Selects

For example, I can do this:

Dir.glob(Path.join(“/path/to/my/files/**”,”*.dll”) + Dir.glob(Path.join(“/path/to/my/files/**”,”*.pdb”)

or better I can use rake’s FileList and a more concise File.join:

FileList.new(Path.join(“path”,”to”,”my”,”files”,”*.{dll,pdb,xml}”))

Directory Ops

I wanted to copy a file structure from one directory to another, but preserving the structure from the original. I had a hard time figuring out the ruby way of doing this, but this seems to do the trick:

FileList.new(File.join(WEB_DIR,"**","*.{spark,asax,aspx,ascx,ashx}"),
	File.join(WEB_DIR,"bin","*.{dll,pdb}"),
	File.join("#{BUILD_CONFIG_DIR}/**", "*")
	).each do |file|			
	path = File.join(DEPLOY_WEB_DIR,file.gsub(WEB_DIR,""))
	target = File.dirname(path)
	File.makedirs(target)			
	cp Pathname.new(file), Pathname.new(target)#bug in ruby for to_str invocation workaround
end	

Configuration & Templating

I like the config.yaml RoR convention, so here’s what I came up with. First, two simple classes:

require 'yaml'
class Environment
	attr_accessor :development,:test,:production
	
	def [](name)
		if name.downcase=="development" then development
		elsif name.downcase=="test" then test
		elsif name.downcase=="production" then production
		end	
	end
end

class Configuration
	attr_accessor :service_path, :database_name, :connection_string, :log_level,:static_files_url  ,:dev  	
	# Support templating of member data.
    def get_binding				
		binding
    end
end

Plz…Ignore the crappy [] hack in Environment . These two classes will be read in by ERB like so:

desc "Expand templates"
task :expand => [:clean] do				
	config = YAML::load(File.open(File.join(CONFIG_DIR,"config.yaml")))			
	b = config[ENVIRONMENT].get_binding		
	FileList.new(File.join(CONFIG_DIR,"**","*.{template}"),File.join(INSTALLER_DIR,"**","*.{template}")).each do |file|
		path = ExpandTemplate.new().write(file,b)			
	end				
end 	

Here’s my config.yaml. Note how we map to the objects I defined above :

--- !ruby/object:Environment 
development: !ruby/object:Configuration    
    database_name: MaterialsTesting_Dev 
    connection_string: my_connection_string 
    log_level: DEBUG 
    static_files_url: http://static.local.com/MaterialsTesting 
test: !ruby/object:Configuration    
    database_name: MaterialsTesting_Test 
    connection_string: my_connection_string 
    log_level: DEBUG 
    static_files_url: http://static.local.com/MaterialsTesting 
production: !ruby/object:Configuration    
    database_name: MaterialsTesting 
    connection_string: my_connection_string 
    log_level: INFO 
    static_files_url: http://static.local.com/MaterialsTesting

Now we can use the ExpandTemplate call:

class ExpandTemplate		
	def write(file,b)							
		template = File.read(file)
		erb = ERB.new(template,0,"%<>")
		output_file_name = File.join(BUILD_DIR,file.gsub(".template",""))		
		output = File.open(output_file_name, 'w') do |file|
			file.puts erb.result(b) 			
		end	
		output_file_name
	end
	
end

So far this has been fun ripping  out nant scripts and replacing them with rake.