From 948a0919760c911b827d2a96dc717e0d14090cbf Mon Sep 17 00:00:00 2001
From: Arturo Fonseca <arturofonsecas32@gmail.com>
Date: Fri, 21 Apr 2023 22:12:37 -0300
Subject: [PATCH] =?UTF-8?q?torna=20carregamento=20de=20imagens=20"lazy"=20?=
 =?UTF-8?q?com=20extens=C3=A3o=20do=20asciidoctor?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Isso é feito criando uma extensão de pós-processamento do asciidoctor que
adiciona, com regex, a string 'loading="lazy"' para cada elemento "img"
no final do processamento do arquivo HTML de saída.
---
 build.sh                            |  2 +-
 ferramentas/addLazyLoadingImages.rb | 19 +++++++++++++++++++
 livro.adoc                          |  3 +--
 3 files changed, 21 insertions(+), 3 deletions(-)
 create mode 100644 ferramentas/addLazyLoadingImages.rb

diff --git a/build.sh b/build.sh
index 58267c1..7b4376a 100755
--- a/build.sh
+++ b/build.sh
@@ -1,4 +1,4 @@
 #!/bin/bash
 set -e  # exit when any command fails
-asciidoctor livro.adoc -o index.html
+asciidoctor -r ./ferramentas/addLazyLoadingImages.rb livro.adoc -o index.html
 open index.html
diff --git a/ferramentas/addLazyLoadingImages.rb b/ferramentas/addLazyLoadingImages.rb
new file mode 100644
index 0000000..078986c
--- /dev/null
+++ b/ferramentas/addLazyLoadingImages.rb
@@ -0,0 +1,19 @@
+include Asciidoctor
+
+class AddLazyLoadingImages < Asciidoctor::Extensions::Postprocessor
+  def process document, output
+    if document.basebackend? 'html'
+      replacement = %(<img loading="lazy" \\1>)
+      output = output.gsub(/<img(.*?)>/m, replacement)
+    end
+    output
+  end
+end
+
+Asciidoctor::Extensions.register do
+  postprocessor AddLazyLoadingImages
+end
+
+Asciidoctor.convert_file 'livro.adoc', safe: :safe
+
+
diff --git a/livro.adoc b/livro.adoc
index 1c4c379..8c1d1ef 100644
--- a/livro.adoc
+++ b/livro.adoc
@@ -7,7 +7,6 @@ include::atributos-pt_BR.adoc[]
 :xrefstyle: short
 :sectnums:
 :sectlinks:
-:data-uri:
 :toc:
 :toclevels: 2
 :!chapter-signifier:
@@ -159,4 +158,4 @@ include::capitulos/cap21.adoc[]
 
 == 🚧 Descritores de atributos
 
-== 🚧 Metaprogramação com classes
\ No newline at end of file
+== 🚧 Metaprogramação com classes