[Feature, Federation, Port: hometown@b3e6597] Support locally cached inline images [+ Monsterfork additions]

Changes added by Monsterfork:
- Do not limit to only Articles
- Reuse existing media; retroactively using more-detailed descriptions
- Also scrub carrige returns between tags
- Handle download failures
- Attach to statuses and keep track of inlined media
- Handle local edits

Co-authored-by: Fire Demon <firedemon@creature.cafe>

1 files changed, 30 insertions, 0 deletions

diff --git a/app/lib/img_tag_handler.rb b/app/lib/img_tag_handler.rb
new file mode 100644
index 000000000..0263e1cbd
--- /dev/null
+++ b/app/lib/img_tag_handler.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+class ImgTagHandler < ::Ox::Sax
+  attr_reader :srcs
+  attr_reader :alts
+
+  def initialize
+    @stack = []
+    @srcs = []
+    @alts = {}
+  end
+
+  def start_element(element_name)
+    @stack << [element_name, {}]
+  end
+
+  def end_element(_)
+    self_name, self_attributes = @stack[-1]
+    if self_name == :img && !self_attributes[:src].nil?
+      @srcs << self_attributes[:src]
+      @alts[self_attributes[:src]] = self_attributes[:alt]&.strip
+    end
+    @stack.pop
+  end
+
+  def attr(attribute_name, attribute_value)
+    _name, attributes = @stack.last
+    attributes[attribute_name] = attribute_value&.strip
+  end
+end