Add special API for JS, don't register implicitly after require

5 files changed, 140 insertions, 9 deletions

diff --git a/README.adoc b/README.adoc
index 46498df..af8c70b 100644
--- a/README.adoc
+++ b/README.adoc
@@ -109,11 +109,42 @@ IMPORTANT: Bundler automatically _requires_ all the specified gems.
 ----
 // Load asciidoctor.js and {gem-name}.
 const asciidoctor = require('asciidoctor.js')()
-require('{gem-name}')
+const interdocReftextExt = require('{gem-name}')
+
+// See documentation at the end of this section.
+const options = {
+  asciidocExts: ['.adoc'],
+}
+
+// Configure the extension and register it into the global registry.
+interdocReftextExt.register(asciidoctor.Extensions, options)
 
 // Convert the file to HTML.
-asciidoctor.convertFile("./README.adoc")
+asciidoctor.convertFile('./README.adoc')
+----
+
+If you don’t want to register the extension globally, you can also pass a custom registry to the `register` function:
+
+[source, js]
 ----
+// ...
+
+const registry = asciidoctor.Extensions.create()
+interdocReftextExt.register(registry, options)
+
+const html = asciidoctor.convertFile('./README.adoc', {
+  'extension_registry': registry,
+})
+----
+
+.*Options:*
+asciidocExts::
+  AsciiDoc file extensions (e.g. `.adoc`).
+  Default is `['.adoc', '.asciidoc', '.ad']`.
+
+raiseExceptions::
+  Whether to raise exceptions (`true`), or just log them (`false`).
+  Default is `true`.
 
 
 == License
diff --git a/Rakefile b/Rakefile
index bc86f92..54fd891 100644
--- a/Rakefile
+++ b/Rakefile
@@ -32,12 +32,15 @@ namespace :build do
       dynamic_require_severity: :error,
     })
     builder.append_paths 'lib'
-    builder.build 'asciidoctor-interdoc-reftext'
+    builder.build 'asciidoctor/interdoc_reftext'
 
     out_file = 'js/asciidoctor-interdoc-reftext.js'
 
     mkdir_p(File.dirname(out_file), verbose: false)
-    File.binwrite out_file, builder.to_s
+    File.open(out_file, 'w') do |file|
+      template = File.read('src/asciidoctor-interdoc-reftext.tmpl.js')
+      file << template.sub('//OPAL-GENERATED-CODE//', builder.to_s)
+    end
     File.binwrite "#{out_file}.map", builder.source_map
   end
 end
diff --git a/lib/asciidoctor/interdoc_reftext.rb b/lib/asciidoctor/interdoc_reftext.rb
index dc884cb..165bd13 100644
--- a/lib/asciidoctor/interdoc_reftext.rb
+++ b/lib/asciidoctor/interdoc_reftext.rb
@@ -1,9 +1,12 @@
 # frozen_string_literal: true
-require 'asciidoctor' unless RUBY_PLATFORM == 'opal'
-require 'asciidoctor/extensions' unless RUBY_PLATFORM == 'opal'
 require 'asciidoctor/interdoc_reftext/version'
 require 'asciidoctor/interdoc_reftext/processor'
 
-Asciidoctor::Extensions.register do
-  treeprocessor Asciidoctor::InterdocReftext::Processor
+unless RUBY_PLATFORM == 'opal'
+  require 'asciidoctor'
+  require 'asciidoctor/extensions'
+
+  Asciidoctor::Extensions.register do
+    treeprocessor Asciidoctor::InterdocReftext::Processor
+  end
 end
diff --git a/lib/asciidoctor/interdoc_reftext/version.rb b/lib/asciidoctor/interdoc_reftext/version.rb
index 2913b0e..d52fde6 100644
--- a/lib/asciidoctor/interdoc_reftext/version.rb
+++ b/lib/asciidoctor/interdoc_reftext/version.rb
@@ -3,6 +3,6 @@
 module Asciidoctor
   module InterdocReftext
     # Version of the asciidoctor-interdoc-reftext gem.
-    VERSION = '0.3.0'.freeze
+    VERSION = '0.3.0'
   end
 end
diff --git a/src/asciidoctor-interdoc-reftext.tmpl.js b/src/asciidoctor-interdoc-reftext.tmpl.js
new file mode 100644
index 0000000..495643e
--- /dev/null
+++ b/src/asciidoctor-interdoc-reftext.tmpl.js
@@ -0,0 +1,94 @@
+(function (Opal) {
+  function initialize (Opal) {
+//OPAL-GENERATED-CODE//
+  }
+
+  var mainModule
+
+  function resolveModule (name) {
+    if (!mainModule) {
+      checkAsciidoctor()
+      initialize(Opal)
+      mainModule = Opal.const_get_qualified(Opal.Asciidoctor, 'InterdocReftext')
+    }
+    if (!name) {
+      return mainModule
+    }
+    return Opal.const_get_qualified(mainModule, name)
+  }
+
+  function checkAsciidoctor () {
+    if (typeof Opal.Asciidoctor === 'undefined') {
+      throw new TypeError('Asciidoctor.js is not loaded')
+    }
+  }
+
+  /**
+   * @param {Object} opts
+   * @param {String[]} opts.asciidocExts AsciiDoc file extensions (e.g. `.adoc`).
+   *   Default is `['.adoc', '.asciidoc', '.ad']`.
+   * @param {boolean} opts.raiseExceptions Whether to raise exceptions (`true`),
+   *   or just log them (`false`). Default is `true`.
+   * @return A new instance of `Asciidoctor::InterdocReftext::Processor`.
+   */
+  function TreeProcessor (opts) {
+    opts = opts || {}
+
+    var processor = resolveModule('Processor').$new(Opal.hash({
+      resolver_class: opts.resolverClass,
+      asciidoc_exts: opts.asciidocExts,
+      logger: opts.logger,
+      raise_exceptions: opts.raiseExceptions,
+    }))
+    processor.process = processor.$process
+
+    return processor
+  }
+
+  /**
+   * @return {string} Version of this extension.
+   */
+  function getVersion () {
+    return resolveModule().$$const.VERSION.toString()
+  }
+
+  /**
+   * Creates and configures the Inter-doc Reference Text extension and registers
+   * it in the extensions registry.
+   *
+   * @param registry The Asciidoctor extensions registry to register this
+   *   extension into. Defaults to the global Asciidoctor registry.
+   * @param {Object} opts See {TreeProcessor} (optional).
+   * @throws {TypeError} if the *registry* is invalid or Asciidoctor.js is not loaded.
+   */
+  function register (registry, opts) {
+    if (!registry) {
+      checkAsciidoctor()
+      registry = Opal.Asciidoctor.Extensions
+    }
+    var processor = TreeProcessor(opts)
+
+    // global registry
+    if (typeof registry.register === 'function') {
+      registry.register(function () {
+        this.treeProcessor(processor)
+      })
+    // custom registry
+    } else if (typeof registry.block === 'function') {
+      registry.treeProcessor(processor)
+    } else {
+      throw new TypeError('Invalid registry object')
+    }
+  }
+
+  var facade = {
+    TreeProcessor: TreeProcessor,
+    getVersion: getVersion,
+    register: register,
+  }
+
+  if (typeof module !== 'undefined' && module.exports) {
+    module.exports = facade
+  }
+  return facade
+})(Opal);