Module: FunWith::Patterns::Loader::ClassMethods

Defined in:
lib/fun_with/patterns/loader/class_methods.rb

Instance Method Summary collapse

Instance Method Details

#loader_pattern_configure(*args) ⇒ Object

Handle the initial configuration of the class.

:bracketwise_lookup : Instead of looking up an object by LoaderBearingClass.loader_pattern_registry_lookup(:keyword)

you can simply use LoaderBearingClass[:keyword]

:warn_on_key_changes : Warns whenever the registry overwrites an existing key. Useful for debugging, sometimes.

Some configuration directives are given as hashes. Multiple directives may be combined into a single hash.

=> <METHOD_SYM> : The method for asking the object what name it should be lookupable under.

=> (true|false) : How noisy do you want the loading to be?

=> :eval

=> :instance_exec

=> <PROC>



144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
 
# File 'lib/fun_with/patterns/loader/class_methods.rb', line 144

def loader_pattern_configure( *args )
  for arg in args
    case arg
    when :bracketwise_lookup
      self.extend( Features::BracketwiseLookup )
    when :warn_on_key_changes
      @loader_pattern_warn_on_key_changes = true
    when :dont_warn_on_key_changes
      @loader_pattern_warn_on_key_changes = false
    when Hash
      for key, val in arg
        case key
        when :key
          self.class_eval do
            eval( "alias :loader_pattern_registry_key #{val.to_sym.inspect}" )
          end
        when :verbose
          self.loader_pattern_verbose( val )
        when :style
          case val     # styles allowed: :eval, :instance_exec
          when :eval
            self.extend( LoadingStyles::Eval )
          when :instance_exec
            self.extend( LoadingStyles::InstanceExec )
          when :yaml
            self.extend( LoadingStyles::YAML )
            self.loader_pattern_extension( [:yml, :yaml] )
          else
            raise "Unknown Loader loading style: #{val.inspect}"
          end
        end
      end
    end
  end
end

#loader_pattern_extension(ext = nil) ⇒ Object

By default, looks for .rb files to evaluate ext => :all (or “*”) to load every file from directory. ext => :rb (or “rb”) to load all .rb files (this is default) call without arguments to inquire about current extension.



9
10
11
12
13
14
15
16
17
18
19
20
 
# File 'lib/fun_with/patterns/loader/class_methods.rb', line 9

def loader_pattern_extension( ext = nil )
  case ext
  when nil
    # do nothing
  when "*", :all
    @loader_pattern_extension = "*"
  else
    @loader_pattern_extension = ext
  end

  @loader_pattern_extension
end

#loader_pattern_is_item_registerable?(item) ⇒ Boolean

Returns:

  • (Boolean) 


92
93
94
95
96
97
98
99
100
 
# File 'lib/fun_with/patterns/loader/class_methods.rb', line 92

def loader_pattern_is_item_registerable?( item )
  return true if loader_pattern_only_register_classes.fwf_blank?

  for klass in @loader_pattern_only_register_classes
    return true if item.is_a?( klass )
  end

  return false
end

#loader_pattern_load_from_dir(*dirs) ⇒ Object

Assumes that every file in the directory and subdirectories contain ruby code that will yield an object that the loader is looking for. It also automatically adds the resulting object to a registry. You may want to override this if you’re looking for different behavior.



107
108
109
110
111
112
113
114
115
116
117
118
 
# File 'lib/fun_with/patterns/loader/class_methods.rb', line 107

def loader_pattern_load_from_dir( *dirs )
  for dir in dirs
    dir = dir.fwf_filepath
    @loader_pattern_directories ||= []
    @loader_pattern_directories << dir
    
    for file in dir.glob( :ext => self.loader_pattern_extension, :recurse => true )
      obj = self.loader_pattern_load_item( file )
      self.loader_pattern_register_item( obj ) if self.loader_pattern_is_item_registerable?( obj )
    end
  end
end

#loader_pattern_loaded_directories ⇒ Object 



120
121
122
 
# File 'lib/fun_with/patterns/loader/class_methods.rb', line 120

def loader_pattern_loaded_directories
  @loader_pattern_directories ||= []
end

#loader_pattern_only_register_classes(*args) ⇒ Object 



84
85
86
87
88
89
90
 
# File 'lib/fun_with/patterns/loader/class_methods.rb', line 84

def loader_pattern_only_register_classes( *args )
  if args.length > 0
    @loader_pattern_only_register_classes = args
  end

  @loader_pattern_only_register_classes || []
end

#loader_pattern_register_item(obj, key = nil) ⇒ Object

Default, may want to override how the registry behaves. If you don’t provide a key argument, then the object needs to respond to .loader_pattern_registry_key()



51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
 
# File 'lib/fun_with/patterns/loader/class_methods.rb', line 51

def loader_pattern_register_item( obj, key = nil )
  return nil if obj.nil?
  @loader_pattern_registry ||= {}

  if key.nil?
    if obj.respond_to?( :loader_pattern_registry_key )
      key = obj.loader_pattern_registry_key
    else
      raise "#{self.class} not registered.  No registry key given, and object does not respond to .loader_pattern_registry_key()."
    end
  end

  if loader_pattern_is_item_registerable?( obj )
    if @loader_pattern_warn_on_key_changes && loader_pattern_registry_lookup( key )
      warn( "class #{self} is replacing lookup key #{key.inspect}" )
    end

    return @loader_pattern_registry[ key ] = obj
  else
    warn( "#{obj} is not an instance of a registerable class.  Registerable classes: #{self.loader_pattern_only_register_classes.inspect}" )
    return nil
  end
end

#loader_pattern_registry ⇒ Object 



80
81
82
 
# File 'lib/fun_with/patterns/loader/class_methods.rb', line 80

def loader_pattern_registry
  @loader_pattern_registry
end

#loader_pattern_registry_lookup(key) ⇒ Object 



75
76
77
78
 
# File 'lib/fun_with/patterns/loader/class_methods.rb', line 75

def loader_pattern_registry_lookup( key )
  @loader_pattern_registry ||= {}
  @loader_pattern_registry[key]
end

#loader_pattern_rescue_failing_item_load(file, &block) ⇒ Object 



27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
 
# File 'lib/fun_with/patterns/loader/class_methods.rb', line 27

def loader_pattern_rescue_failing_item_load( file, &block )
  file = file.fwf_filepath.expand
  if file.file?
    obj = yield
    STDOUT.puts( "Loaded file #{file}" ) if self.loader_pattern_verbose
    
    obj
  else
    STDERR.puts( "(#{self.class}) Load failed, no such file: #{file}" )
  end
rescue Exception => e
  STDERR.puts( "Could not load file #{file}.  Reason: #{e.class.name} #{e.message}" )

  if self.loader_pattern_verbose
    STDERR.puts( puts e.backtrace.map{|line| "\t\t#{line}"}.join("\n") )
    STDERR.puts( "\n" )
  end

  nil
end

#loader_pattern_verbose(verbosity = nil) ⇒ Object 



22
23
24
25
 
# File 'lib/fun_with/patterns/loader/class_methods.rb', line 22

def loader_pattern_verbose( verbosity = nil )
  @loader_pattern_verbose = verbosity unless verbosity.nil?
  @loader_pattern_verbose
end