From e.i at bluewin.ch  Tue Jul 31 07:20:21 2007
From: e.i at bluewin.ch (Emanuel =?ISO-8859-1?Q?Inderm=FChle?=)
Date: Tue, 31 Jul 2007 13:20:21 +0200
Subject: [Rake-devel] List of Files as prerequisits
Message-ID: <1185880821.16157.19.camel@localhost>

Hello

I have a question concerning the use of rake. Sorry for using dhe
developper mailing list, but there was no other.

How do i make a task that has as prerequisit a list of files.
As this is the nature of tasks their requisits may be missing.

So i cant make a FileList of files that are missing.

There is a list of these files, stored in a other file (its name ist
letters.txt).

But this file will be created by another task. How do i implement this
problem in rake. 

My try:

--------code ------------

def methodToGetFileListFromlettersFile (path,extension = "")
    hmms = []
    File.open("system/system/letter.txt", "r") do |file|
        file.each_line do | line |
            hmms << path + line + extension
        end
    end
    return hmms
end

rule ".hmm" do | t | 
    `touch #{t.name}`
    #is in reality more complex
end

file "letter.txt" do
     #generate "letter.txt" somehow
end

task :combineFiles=>["letter.txt"]+methodToGetFileListFromletterFile("systempath/","hmm")
	do
    #do something with the files
end

-----------/code-------------

But then i realized that when the task are created the file letter.txt
is not existing so methodToGetFileListFromlettersFile() will fail.

What is a possible solution for my problem


Thanks for every answer



From zimbatm at oree.ch  Tue Jul 31 10:51:31 2007
From: zimbatm at oree.ch (Jonas Pfenniger)
Date: Tue, 31 Jul 2007 16:51:31 +0200
Subject: [Rake-devel] List of Files as prerequisits
In-Reply-To: <1185880821.16157.19.camel@localhost>
References: <1185880821.16157.19.camel@localhost>
Message-ID: <e3caf1460707310751g53be69e7oe003fbdf9270916c@mail.gmail.com>

Hi Emanuel,

your problem (I think) is that you are relying on the execution order of
your task's dependencies. Here is a snippet that should work :

file "letter.txt" do
    #generate "letter.txt" somehow
end

task :ensure_hmms => "letter.txt" do
  (File.read('letter.txt').split("\n") - FileList['*.hmm']).each do
|missing_hmm|
    sh :touch, missing_hmm
  end
end

task :combineFiles=>:ensure_hmms do
   #do something with the files
end

-- 
Cheers,
  zimbatm
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