lib/logging/utils.rb in logging-1.1.1 vs lib/logging/utils.rb in logging-1.1.2

@@ -1,6 +1,7 @@
 
+# --------------------------------------------------------------------------
 class Hash
 
   # call-seq:
   #    getopt( key, default = nil, :as => class )
   #
@@ -38,10 +39,11 @@
     when :Symbol;  String(val).intern
     else val end
   end
 end
 
+# --------------------------------------------------------------------------
 class String
 
   # call-seq:
   #    reduce( width, ellipses = '...' )    #=> string
   #
@@ -67,10 +69,11 @@
 
     left << ellipses << right
   end
 end
 
+# --------------------------------------------------------------------------
 class Module
 
   # call-seq:
   #    logger_name    #=> string
   #
@@ -100,9 +103,83 @@
     }
     return 'anonymous'
   end
 end
 
+# --------------------------------------------------------------------------
+module Kernel
+
+  # Settiing this global variable to +false+ will disable rubygems from
+  # being loaded at all.
+  $use_rubygems = true unless defined? $use_rubygems
+
+  # Setting this global variable to +true+ will cause an error message to be
+  # displayed when a library cannot be required.
+  $whiny_require = false unless defined? $whiny_require
+
+  # call-seq:
+  #    require!( string )
+  #    require!( string, gem_version )
+  #    require!( string, gem_name, gem_version )
+  #
+  # Attempt to the load the library named _string_ using the standard
+  # Kernel#require method. If the library cannot be loaded then require
+  # rubygems and retry the original require of the library.
+  #
+  # Raises a LoadError if the library cannot be loaded.
+  #
+  # If a _gem_version_ is given, then the rubygems +gem+ command is used to
+  # load the specific version of the gem. The library _string_ is used for
+  # the _gem_name_ if one is omitted.
+  #
+  def require!( string, *args )
+    return require(string) if args.empty?
+
+    name, version = *args
+    version, name = name, string if name =~ %r/^[0-9<>=~]/
+    version ||= '> 0'
+
+    gem name, version
+    require(string)
+  rescue LoadError, NoMethodError
+    retry if $use_rubygems and require('rubygems')
+    if $whiny_require
+      name ||= string
+      $stderr.puts "Required library #{string.inspect} could not be loaded."
+      $stderr.puts "Try:\tgem install #{name}"
+    end
+    raise
+  end
+
+  # call-seq:
+  #    require?( string )
+  #    require?( string, gem_version )
+  #    require?( string, gem_name, gem_version )
+  #
+  # Attempt to the load the library named _string_ using the standard
+  # Kernel#require method. If the library cannot be loaded then require
+  # rubygems and retry the original require of the library.
+  #
+  # Returns +true+ if the library was successfully loaded. Returns +false+
+  # if the library could not be loaded. This method will never raise an
+  # exception.
+  #
+  # If a _gem_version_ is given, then the rubygems +gem+ command is used to
+  # load the specific version of the gem. The library _string_ is used for
+  # the _gem_name_ if one is omitted.
+  #
+  def require?( string, *args )
+    wr, $whiny_require = $whiny_require, false
+    require!(string, *args)
+    return true
+  rescue LoadError
+    return false
+  ensure
+    $whiny_require = wr
+  end
+end  # module Kernel
+
+# --------------------------------------------------------------------------
 class ReentrantMutex < Mutex
 
   def initialize
     super
     @locker = nil