resolves #276 try to use KindleGen/EPUBCheck binary from $PATH (#277)

CHANGELOG.adoc

@@ -11,6 +11,8 @@ For a detailed view of what has changed, refer to the {uri-repo}/commits/master[
 * make `KINDLEGEN` env var work again (#269)
 * enable Pygments on non-Windows JRuby platforms (#264)
 * provide a human-readable error message when we fail to find KindleGen (#268)
+* try to use KindleGen/EPUBCheck binary from `$PATH` (#276)
+* add `ebook-kindlegen-path`/`ebook-epubcheck-path` attributes to override KindleGen/EPUBCheck executable location (#276)
 
 == 1.5.0.alpha.11 (2020-01-26) - @slonopotamus
 

README.adoc

@@ -540,21 +540,39 @@ For more information about this attribute and other related attributes, see {uri
 *-D, --destination-dir* ::
   Writes files to specified directory (defaults to the current directory)
 
+*-a ebook-epubcheck-path=<path>*::
+  Specifies path to EPUBCheck executable to use with `-a ebook-validate`.
+  This attribute takes precedence over `EPUBCHECK` environment variable.
+
 *-a ebook-extract* ::
   Extracts the EPUB3 to a folder in the destination directory after the file is generated
 
 *-a ebook-format=<format>* ::
   Specifies the ebook format to generate (epub3 or kf8, default: epub3)
 
+*-a ebook-kindlegen-path=<path>*::
+  Specifies path to KindleGen executable to use when producing KF8/Mobi.
+  This attribute takes precedence over `KINDLEGEN` environment variable.
+
 *-a ebook-validate* ::
-  Runs {uri-epubcheck}[EpubCheck] to validate output file against the EPUB3 specification
+  Runs {uri-epubcheck}[EPUBCheck] to validate output file against the EPUB3 specification
 
 *-a ebook-compress=<0|1|2|none|standard|huffdic>* ::
   Controls the compression type used by kindlegen (0=none [default if unset], 1=standard [default if empty], 2=huffdic)
 
 *-v, --version* ::
   Display the program version
 
+=== Environment variables
+
+*EPUBCHECK*::
+  Specifies path to EPUBCheck executable to use with `-a ebook-validate`.
+  Effect of this variable can be overriden with `-a ebook-epubcheck-path` attribute.
+
+*KINDLEGEN*::
+  Specifies path to KindleGen executable to use when producing KF8/Mobi.
+  Effect of this variable can be overriden with `-a ebook-kindlegen-path` attribute.
+
 === EPUB3 Archive Structure
 
 Here's a sample manifest of files found in an EPUB3 document produced by {project-name}.

WORKLOG.adoc

@@ -35,7 +35,6 @@
 * allow role to be applied to chapter (which means the role must be on the document)
 * should we enable hyphens in non-Kindle?
  ** we can reenable once we confirm it doesn't crash Kindle for Mac
-* document KINDLEGEN and EPUBCHECK env vars
 * part vs chapter? a difference?
 
 * create a video to demonstrate Google Play Books read aloud reading complete sentences in books generated with Asciidoctor EPUB3

lib/asciidoctor-epub3/converter.rb

@@ -21,13 +21,17 @@ def initialize backend, opts
         htmlsyntax 'xml'
         @validate = false
         @extract = false
+        @kindlegen_path = nil
+        @epubcheck_path = nil
       end
 
       def convert node, name = nil
         if (name ||= node.node_name) == 'document'
           @validate = node.attr? 'ebook-validate'
           @extract = node.attr? 'ebook-extract'
           @compress = node.attr 'ebook-compress'
+          @kindlegen_path = node.attr 'ebook-kindlegen-path'
+          @epubcheck_path = node.attr 'ebook-epubcheck-path'
           spine_items = node.references[:spine_items]
           if spine_items.nil?
             logger.error %(#{::File.basename node.document.attr('docfile')}: failed to find spine items, produced file will be invalid)
@@ -44,7 +48,7 @@ def convert node, name = nil
 
       # FIXME: we have to package in write because we don't have access to target before this point
       def write packager, target
-        packager.package validate: @validate, extract: @extract, compress: @compress, target: target
+        packager.package validate: @validate, extract: @extract, compress: @compress, kindlegen_path: @kindlegen_path, epubcheck_path: @epubcheck_path, target: target
         nil
       end
     end

lib/asciidoctor-epub3/packager.rb

@@ -609,30 +609,46 @@ def package options = {}
 
         if fmt == :kf8
           # QUESTION shouldn't we validate this epub file too?
-          distill_epub_to_mobi epub_file, target, options[:compress]
+          distill_epub_to_mobi epub_file, target, options[:compress], options[:kindlegen_path]
         elsif options[:validate]
-          validate_epub epub_file
+          validate_epub epub_file, options[:epubcheck_path]
         end
       end
 
-      def distill_epub_to_mobi epub_file, target, compress
-        if !(kindlegen_cmd = ENV['KINDLEGEN']).nil?
-          argv = [kindlegen_cmd]
-        else
-          begin
-            require 'kindlegen' unless defined? ::Kindlegen
-          rescue LoadError => e
-            raise 'Unable to find KindleGen. Either install the kindlegen gem or set KINDLEGEN environment variable with path to KindleGen executable', cause: e
-          end
-          argv = [::Kindlegen.command.to_s]
+      def get_kindlegen_command kindlegen_path
+        unless kindlegen_path.nil?
+          logger.debug %(Using ebook-kindlegen-path attribute: #{kindlegen_path})
+          return [kindlegen_path]
+        end
+
+        unless (result = ENV['KINDLEGEN']).nil?
+          logger.debug %(Using KINDLEGEN env variable: #{result})
+          return [result]
         end
+
+        begin
+          require 'kindlegen' unless defined? ::Kindlegen
+          result = ::Kindlegen.command.to_s
+          logger.debug %(Using KindleGen from gem: #{result})
+          [result]
+        rescue LoadError => e
+          logger.debug %(#{e}; Using KindleGen from PATH)
+          [%(kindlegen#{::Gem.win_platform? ? '.exe' : ''})]
+        end
+      end
+
+      def distill_epub_to_mobi epub_file, target, compress, kindlegen_path
         mobi_file = ::File.basename target.sub(EpubExtensionRx, '.mobi')
         compress_flag = KindlegenCompression[compress ? (compress.empty? ? '1' : compress.to_s) : '0']
-        argv += ['-dont_append_source', compress_flag, '-o', mobi_file, epub_file].compact
 
-        # This duplicates Kindlegen.run, but we want to override executable
-        out, err, res = Open3.capture3(*argv) do |r|
-          r.force_encoding 'UTF-8' if windows? && r.respond_to?(:force_encoding)
+        argv = get_kindlegen_command(kindlegen_path) + ['-dont_append_source', compress_flag, '-o', mobi_file, epub_file].compact
+        begin
+          # This duplicates Kindlegen.run, but we want to override executable
+          out, err, res = Open3.capture3(*argv) do |r|
+            r.force_encoding 'UTF-8' if ::Gem.win_platform? && r.respond_to?(:force_encoding)
+          end
+        rescue Errno::ENOENT => e
+          raise 'Unable to run KindleGen. Either install the kindlegen gem or set KINDLEGEN environment variable with path to KindleGen executable', cause: e
         end
 
         out.each_line do |line|
@@ -650,15 +666,34 @@ def distill_epub_to_mobi epub_file, target, compress
         end
       end
 
-      def validate_epub epub_file
-        if !(epubcheck = ENV['EPUBCHECK']).nil?
-          argv = [epubcheck]
-        else
-          argv = [::Gem.ruby, ::Gem.bin_path('epubcheck-ruby', 'epubcheck')]
+      def get_epubcheck_command epubcheck_path
+        unless epubcheck_path.nil?
+          logger.debug %(Using ebook-epubcheck-path attribute: #{epubcheck_path})
+          return [epubcheck_path]
+        end
+
+        unless (result = ENV['EPUBCHECK']).nil?
+          logger.debug %(Using EPUBCHECK env variable: #{result})
+          return [result]
         end
 
-        argv += ['-w', epub_file]
-        out, err, res = Open3.capture3(*argv)
+        begin
+          result = ::Gem.bin_path 'epubcheck-ruby', 'epubcheck'
+          logger.debug %(Using EPUBCheck from gem: #{result})
+          [::Gem.ruby, result]
+        rescue ::Gem::Exception => e
+          logger.debug %(#{e}; Using EPUBCheck from PATH)
+          ['epubcheck']
+        end
+      end
+
+      def validate_epub epub_file, epubcheck_path
+        argv = get_epubcheck_command(epubcheck_path) + ['-w', epub_file]
+        begin
+          out, err, res = Open3.capture3(*argv)
+        rescue Errno::ENOENT => e
+          raise 'Unable to run EPUBCheck. Either install epubcheck-ruby gem or set EPUBCHECK environment variable with path to EPUBCheck executable', cause: e
+        end
 
         out.each_line do |line|
           logger.info line