util.rb in hirb-0.2.2

- old
+ new

@@ -1,9 +1,10 @@
 module Hirb
+  # Group of handy utility functions used throughout Hirb.
   module Util
     extend self
-    # Returns a constant like const_get() no matter what namespace it's nested in.
+    # Returns a constant like Module#const_get no matter what namespace it's nested in.
     # Returns nil if the constant is not found.
     def any_const_get(name)
       return name if name.is_a?(Module)
       begin
         klass = Object
@@ -19,11 +20,61 @@
     # Recursively merge hash1 with hash2.
     def recursive_hash_merge(hash1, hash2)
       hash1.merge(hash2) {|k,o,n| (o.is_a?(Hash)) ? recursive_hash_merge(o,n) : n}
     end
 
-    # from Rails ActiveSupport
+    # From Rails ActiveSupport, converting undescored lowercase to camel uppercase.
     def camelize(string)
       string.to_s.gsub(/\/(.?)/) { "::#{$1.upcase}" }.gsub(/(?:^|_)(.)/) { $1.upcase }
+    end
+
+    # Used by Hirb::Menu to select items from an array. Array counting starts at 1. Ranges of numbers are specified with a '-' or '..'.
+    # Multiple ranges can be comma delimited. Anything that isn't a valid number is ignored. All elements can be returned with a '*'.
+    # Examples:
+    #    1-3,5-6 -> [1,2,3,5,6]
+    #    *   -> all elements in array
+    #    ''  -> [] 
+    def choose_from_array(array, input, options={})
+      options = {:splitter=>","}.merge(options)
+      return array if input.strip == '*'
+      result = []
+      input.split(options[:splitter]).each do |e|
+        if e =~ /-|\.\./
+          min,max = e.split(/-|\.\./)
+          slice_min = min.to_i - 1
+          result.push(*array.slice(slice_min, max.to_i - min.to_i + 1))
+        elsif e =~ /\s*(\d+)\s*/
+          index = $1.to_i - 1
+          next if index < 0
+          result.push(array[index]) if array[index]
+        end
+      end
+      return result
+    end
+
+    # Determines if a shell command exists by searching for it in ENV['PATH'].
+    def command_exists?(command)
+      ENV['PATH'].split(File::PATH_SEPARATOR).any? {|d| File.exists? File.join(d, command) }
+    end
+
+    # Returns [width, height] of terminal when detected, nil if not detected.
+    # Think of this as a simpler version of Highline's Highline::SystemExtensions.terminal_size()
+    def detect_terminal_size
+      (ENV['COLUMNS'] =~ /^\d+$/) && (ENV['LINES'] =~ /^\d+$/) ? [ENV['COLUMNS'].to_i, ENV['LINES'].to_i] :
+        ( command_exists?('stty') ? `stty size`.scan(/\d+/).map { |s| s.to_i }.reverse : nil )
+    rescue
+      nil
+    end
+
+    # Captures STDOUT of anything run in its block and returns it as string.
+    def capture_stdout(&block)
+      original_stdout = $stdout
+      $stdout = fake = StringIO.new
+      begin
+        yield
+      ensure
+        $stdout = original_stdout
+      end
+      fake.string
     end
   end
 end
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