# HG changeset patch
# User Alessio Caiazza <nolith@abisso.org>
# Parent cf4532e967407044f02fb2161051f0e7bee9911c
Add INI file parser for .hgrc

diff --git a/lib/ini.rb b/lib/ini.rb
new file mode 100644
--- /dev/null
+++ b/lib/ini.rb
@@ -0,0 +1,263 @@
+#
+# ini.rb - read and write ini files
+#
+# Copyright (C) 2007 Jeena Paradies
+# License: GPL
+# Author: Jeena Paradies (info@jeenaparadies.net)
+#
+# == Overview
+#
+# This file provides a read-wite handling for ini files.
+# The data of a ini file is represented by a object which
+# is populated with strings.
+
+class Ini
+  
+  # Class with methods to read from and write into ini files.
+  #
+  # A ini file is a text file in a specific format,
+  # it may include several fields which are sparated by
+  # field headlines which are enclosured by "[]".
+  # Each field may include several key-value pairs.
+  #
+  # Each key-value pair is represented by one line and
+  # the value is sparated from the key by a "=".
+  #
+  # == Examples
+  #
+  # === Example ini file
+  #
+  #   # this is the first comment which will be saved in the comment attribute
+  #   mail=info@example.com
+  #   domain=example.com # this is a comment which will not be saved
+  #   [database]
+  #   db=example
+  #   user=john
+  #   passwd=very-secure
+  #   host=localhost
+  #   # this is another comment
+  #   [filepaths]
+  #   tmp=/tmp/example
+  #   lib=/home/john/projects/example/lib
+  #   htdocs=/home/john/projects/example/htdocs
+  #   [ texts ]
+  #   wellcome=Wellcome on my new website!
+  #   Website description = This is only a example. # and another comment
+  #
+  # === Example object
+  #
+  #   A Ini#comment stores:
+  #   "this is the first comment which will be saved in the comment attribute"
+  #
+  #   A Ini object stores:
+  #
+  #   {
+  #    "mail" => "info@example.com",
+  #    "domain" => "example.com",
+  #    "database" => {
+  #     "db" => "example",
+  #     "user" => "john",
+  #     "passwd" => "very-secure",
+  #     "host" => "localhost"
+  #    },
+  #    "filepaths" => {
+  #     "tmp" => "/tmp/example",
+  #     "lib" => "/home/john/projects/example/lib",
+  #     "htdocs" => "/home/john/projects/example/htdocs"
+  #    }
+  #    "texts" => {
+  #     "wellcome" => "Wellcome on my new website!",
+  #     "Website description" => "This is only a example."
+  #    }
+  #   }
+  #
+  # As you can see this module gets rid of all comments, linebreaks
+  # and unnecessary spaces at the beginning and the end of each
+  # field headline, key or value.
+  #
+  # === Using the object
+  #
+  # Using the object is stright forward:
+  #
+  #   ini = Ini.new("path/settings.ini")
+  #   ini["mail"] = "info@example.com"
+  #   ini["filepaths"] = { "tmp" => "/tmp/example" }
+  #   ini.comment = "This is\na comment"
+  #   puts ini["filepaths"]["tmp"]
+  #   # => /tmp/example
+  #   ini.update()
+  # 
+  
+  #
+  # :inihash is a hash which holds all ini data
+  # :comment is a string which holds the comments on the top of the file
+  #
+  attr_accessor :inihash, :comment
+
+  #
+  # Creating a new Ini object
+  #
+  # +path+ is a path to the ini file
+  # +load+ if nil restores the data if possible
+  #        if true restores the data, if not possible raises an error
+  #        if false does not resotre the data
+  #
+  def initialize(path, load=nil)
+    @path = path
+    @inihash = {}
+    
+    if load or ( load.nil? and FileTest.readable_real? @path )
+      restore()
+    end
+  end
+  
+  #
+  # Retrive the ini data for the key +key+
+  #
+  def [](key)
+    @inihash[key]
+  end
+  
+  #
+  # Set the ini data for the key +key+
+  #
+  def []=(key, value)
+    raise TypeError, "String expected" unless key.is_a? String
+    raise TypeError, "String or Hash expected" unless value.is_a? String or value.is_a? Hash
+    
+    @inihash[key] = value
+  end
+  
+  #
+  # Restores the data from file into the object
+  #
+  def restore()
+    @inihash = Ini.read_from_file(@path)
+    @comment = Ini.read_comment_from_file(@path)
+  end
+  
+  #
+  # Store data from the object in the file
+  #
+  def update()
+    Ini.write_to_file(@path, @inihash, @comment)
+  end
+
+  #
+  # Reading data from file
+  #
+  # +path+ is a path to the ini file
+  #
+  # returns a hash which represents the data from the file
+  #
+  def Ini.read_from_file(path)
+        
+    inihash = {}
+    headline = nil
+    
+    IO.foreach(path) do |line|
+
+      line = line.strip.split(/#/)[0]
+      
+      # read it only if the line doesn't begin with a "=" and is long enough
+      unless line.length < 2 and line[0,1] == "="
+        
+        # it's a headline if the line begins with a "[" and ends with a "]"
+        if line[0,1] == "[" and line[line.length - 1, line.length] == "]"
+          
+          # get rid of the [] and unnecessary spaces
+          headline = line[1, line.length - 2 ].strip
+          inihash[headline] = {}
+        else
+        
+          key, value = line.split(/=/, 2)
+          
+          key = key.strip unless key.nil?
+          value = value.strip unless value.nil?
+          
+          unless headline.nil?
+            inihash[headline][key] = value
+          else
+            inihash[key] = value unless key.nil?
+          end
+        end        
+      end
+    end
+    
+    inihash
+  end
+  
+  #
+  # Reading comments from file
+  #
+  # +path+ is a path to the ini file
+  #
+  # Returns a string with comments from the beginning of the
+  # ini file.
+  #
+  def Ini.read_comment_from_file(path)
+    comment = ""
+    
+    IO.foreach(path) do |line|
+      line.strip!
+      break unless line[0,1] == "#" or line == ""
+      
+      comment << "#{line[1, line.length ].strip}\n"
+    end
+    
+    comment
+  end
+  
+  #
+  # Writing a ini hash into a file
+  #
+  # +path+ is a path to the ini file
+  # +inihash+ is a hash representing the ini File. Default is a empty hash.
+  # +comment+ is a string with comments which appear on the
+  #           top of the file. Each line will get a "#" before.
+  #           Default is no comment.
+  #
+  def Ini.write_to_file(path, inihash={}, comment=nil)
+    raise TypeError, "String expected" unless comment.is_a? String or comment.nil?
+    
+    raise TypeError, "Hash expected" unless inihash.is_a? Hash
+    File.open(path, "w") { |file|
+      
+      unless comment.nil?
+        comment.each do |line|
+          file << "# #{line}"
+        end
+      end
+      
+      file << Ini.to_s(inihash)
+    }
+  end
+  
+  #
+  # Turn a hash (up to 2 levels deepness) into a ini string
+  #
+  # +inihash+ is a hash representing the ini File. Default is a empty hash.
+  #
+  # Returns a string in the ini file format.
+  #
+  def Ini.to_s(inihash={})
+    str = ""
+    
+    inihash.each do |key, value|
+
+      if value.is_a? Hash
+        str << "[#{key.to_s}]\n"
+        
+        value.each do |under_key, under_value|
+          str << "#{under_key.to_s}=#{under_value.to_s unless under_value.nil?}\n"
+        end
+
+      else
+        str << "#{key.to_s}=#{value.to_s unless value.nil?}\n"
+      end
+    end
+    
+    str
+  end
+  
+end
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