Class: Markbridge::Renderers::Discourse::TagLibrary

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/markbridge/renderers/discourse/tag_library.rb

Overview

Library of rendering tags for different element types

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ TagLibrary

Returns a new instance of TagLibrary.



10
11
12
 
# File 'lib/markbridge/renderers/discourse/tag_library.rb', line 10

def initialize
  @tags = {}
end

Class Method Details

.default ⇒ TagLibrary

Create the default tag library for Discourse Markdown.

Each call returns a fresh instance — mutations made to one will not be visible to another.

Returns:



106
107
108
 
# File 'lib/markbridge/renderers/discourse/tag_library.rb', line 106

def self.default
  new.auto_register!
end

Instance Method Details

#[](element_class) ⇒ Tag?

Get tag for an element class

Parameters:

  • element_class (Class)

Returns:



66
67
68
 
# File 'lib/markbridge/renderers/discourse/tag_library.rb', line 66

def [](element_class)
  @tags[element_class]
end

#ast_class_for(tag_constant) ⇒ Class?

Look up the AST element class matching a XxxTag constant via the XxxTag → AST::Xxx naming convention.

Returns:

  • (Class, nil) 


94
95
96
97
98
 
# File 'lib/markbridge/renderers/discourse/tag_library.rb', line 94

def ast_class_for(tag_constant)
  AST.const_get(tag_constant.to_s.sub(/Tag\z/, ""))
rescue NameError
  nil
end

#auto_register! ⇒ self

Auto-register all tags using naming convention Convention: BoldTag handles AST::Bold, ItalicTag handles AST::Italic, etc.

Returns:

  • (self) 


83
84
85
86
87
88
89
 
# File 'lib/markbridge/renderers/discourse/tag_library.rb', line 83

def auto_register!
  Tags.constants.each do |tag_constant|
    element_class = ast_class_for(tag_constant)
    register(element_class, Tags.const_get(tag_constant).new) if element_class
  end
  self
end

#each {|element_class, tag| ... } ⇒ Enumerator

Iterate over registered (element_class, tag) pairs. Useful for debugging custom libraries — e.g. confirming an override has stuck. Iteration order matches registration order.

Yield Parameters:

  • element_class (Class)
  • tag (Tag)

Returns:

  • (Enumerator) —

    when no block is given



76
77
78
 
# File 'lib/markbridge/renderers/discourse/tag_library.rb', line 76

def each(&block)
  @tags.each(&block)
end

#initialize_copy(other) ⇒ Object

When a TagLibrary is dup‘d / clone’d, ensure the internal @tags Hash is independent of the source. Without this, both copies would share the same underlying Hash and mutations to one would silently affect the other.



18
19
20
21
 
# File 'lib/markbridge/renderers/discourse/tag_library.rb', line 18

def initialize_copy(other)
  super
  @tags = @tags.dup
end

#merge!(mapping) ⇒ self

Merge a Hash of class → Tag mappings on top of this library in-place. A nil value unregisters the corresponding class (so the default auto-passthrough kicks in).

Named with a trailing ! because it mutates self —mirroring Ruby’s Hash#merge / Hash#merge! convention. Use dup first if you need a non-destructive merge.

Parameters:

  • mapping (Hash{Class => Tag, nil})

Returns:

  • (self) 


52
53
54
55
56
57
58
59
60
61
 
# File 'lib/markbridge/renderers/discourse/tag_library.rb', line 52

def merge!(mapping)
  mapping.each_pair do |klass, tag|
    if tag.nil?
      unregister(klass)
    else
      register(klass, tag)
    end
  end
  self
end

#register(element_class, tag) ⇒ Object

Register a tag for an element class

Parameters:

  • element_class (Class) —

    the element class

  • tag (Tag) —

    the tag instance



26
27
28
29
 
# File 'lib/markbridge/renderers/discourse/tag_library.rb', line 26

def register(element_class, tag)
  @tags[element_class] = tag
  self
end

#unregister(element_class) ⇒ self

Remove a tag binding so the renderer falls through to render_children for that element class. See Renderer#render for the auto-passthrough path.

Parameters:

  • element_class (Class)

Returns:

  • (self) 


37
38
39
40
 
# File 'lib/markbridge/renderers/discourse/tag_library.rb', line 37

def unregister(element_class)
  @tags.delete(element_class)
  self
end