resolves #2134 add parse_attributes helper to base extension Processor class (PR #3189)

3 files changed, 48 insertions, 0 deletions

diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index 9b8b7eb1..99038dd0 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -93,6 +93,7 @@ Enhancements / Compliance::
   * substitute replacements in author values used in document header (#2441)
   * require space after semi-colon that separates multiple authors (#2441)
   * catalog inline anchors at start of callout list items (#2818) (*@owenh000*)
+  * add parse_attributes helper method to base extension Processor class (#2134)
 
 Improvements::
 
diff --git a/lib/asciidoctor/extensions.rb b/lib/asciidoctor/extensions.rb
index 5e45e08a..1cc16601 100644
--- a/lib/asciidoctor/extensions.rb
+++ b/lib/asciidoctor/extensions.rb
@@ -215,6 +215,21 @@ module Extensions
       parent
     end
 
+    # Public: Parses the attrlist String into a Hash of attributes
+    #
+    # block    - the current AbstractBlock or the parent AbstractBlock if there is no current block (used for applying subs)
+    # attrlist - the list of attributes as a String
+    # opts     - an optional Hash of options to control processing:
+    #            :positional_attributes - an Array of attribute names to map positional arguments to (optional, default: false)
+    #            :sub_attributes - enables attribute substitution on the attrlist argument (optional, default: false)
+    #
+    # Returns a Hash of parsed attributes
+    def parse_attributes block, attrlist, opts = {}
+      return {} if attrlist ? attrlist.empty? : true
+      attrlist = block.sub_attributes attrlist if opts[:sub_attributes] && (attrlist.include? ATTR_REF_HEAD)
+      (AttributeList.new attrlist).parse (opts[:positional_attributes] || [])
+    end
+
     # TODO fill out remaining methods
     [
       [:create_paragraph,     :create_block,  :paragraph],
diff --git a/test/extensions_test.rb b/test/extensions_test.rb
index 1f794acd..a30c1490 100644
--- a/test/extensions_test.rb
+++ b/test/extensions_test.rb
@@ -1474,6 +1474,38 @@ context 'Extensions' do
       end
     end
 
+    test 'can use parse_attributes to parse attrlist' do
+      begin
+        parsed_attrs = nil
+        Asciidoctor::Extensions.register do
+          block do
+            named :attrs
+            on_context :open
+            process do |parent, reader, attrs|
+              parsed_attrs = parse_attributes parent, reader.read_line, positional_attributes: ['a', 'b']
+              parsed_attrs.update parse_attributes parent, 'foo={foo}', sub_attributes: true
+              nil
+            end
+          end
+        end
+        input = <<~'EOS'
+        :foo: bar
+
+        [attrs]
+        --
+        a,b,c,key=val
+        --
+        EOS
+        doc = document_from_string input
+        assert_equal 'a', parsed_attrs['a']
+        assert_equal 'b', parsed_attrs['b']
+        assert_equal 'val', parsed_attrs['key']
+        assert_equal 'bar', parsed_attrs['foo']
+      ensure
+        Asciidoctor::Extensions.unregister_all
+      end
+    end
+
     test 'create_section should set up all section properties' do
       begin
         sect = nil