asciidoctor#118 Add support for Erd

.travis.yml

@@ -16,13 +16,13 @@ before_install:
   - gem --version
   - gem install bundler
   - sudo apt-get update -qq
+install:
   - wget -O phantomjs-2.1.1-linux-x86_64.tar.bz2 https://github.com/pepijnve/asciidoctor-diagram-build/blob/master/linux/x86_64/phantomjs-2.1.1-linux-x86_64.tar.bz2?raw=true
   - tar jxf phantomjs-2.1.1-linux-x86_64.tar.bz2
   - export PHANTOMJS_2=$PWD/phantomjs-2.1.1-linux-x86_64/bin/phantomjs
   - wget -O phantomjs-1.9.8-linux-x86_64.tar.bz2 https://github.com/pepijnve/asciidoctor-diagram-build/blob/master/linux/x86_64/phantomjs-1.9.8-linux-x86_64.tar.bz2?raw=true
   - tar jxf phantomjs-1.9.8-linux-x86_64.tar.bz2
   - export PHANTOMJS_19=$PWD/phantomjs-1.9.8-linux-x86_64/bin/phantomjs
-install:
   - sudo apt-get install -qq graphviz
   - sudo apt-get install -qq python-gtk2
   - pip install --user blockdiag actdiag seqdiag nwdiag

CHANGELOG.adoc

@@ -5,6 +5,7 @@
 Enhancements::
 
   * Apply anti-aliasing to blockdiag generated images
+  * Issue #118: Add support for Erd.
 
 Bug Fixes::
 

README.adoc

@@ -19,6 +19,7 @@ ifndef::env-site[:status:]
 :uri-blockdiag: http://blockdiag.com
 :uri-ditaa: http://ditaa.sourceforge.net/
 :uri-dot: http://www.graphviz.org/content/dot-language
+:uri-erd: https://github.com/BurntSushi/erd
 :uri-graphviz: http://www.graphviz.org
 :uri-imagemagick: http://www.imagemagick.org
 :uri-java: http://java.sun.com
@@ -108,6 +109,7 @@ The following diagram types and output formats are available:
 |{uri-actdiag}[actdiag]      |       |{check}|{check}|
 |{uri-blockdiag}[blockdiag]  |       |{check}|{check}|
 |{uri-ditaa}[ditaa]          |       |{check}|       |
+|{uri-erd}[erd]              |       |{check}|{check}|
 |{uri-dot}[graphviz]         |       |{check}|{check}|
 |<<meme,meme>>               |{check}|{check}|       |
 |{uri-mermaid}[mermaid]      |       |{check}|{check}|
@@ -229,7 +231,7 @@ or load and register each extension individually.
 require 'asciidoctor-diagram/<extension_name>'
 ----
 
-`<extension_name>` can be one of `blockdiag`, `ditaa`, `graphviz`, `meme`, `mermaid`, `plantuml`, `shaape`, or `wavedrom`.
+`<extension_name>` can be one of `blockdiag`, `ditaa`, `erd`, `graphviz`, `meme`, `mermaid`, `plantuml`, `shaape`, or `wavedrom`.
 
 Requiring one or more of these files will automatically register the extensions for all processed documents.
 
@@ -275,6 +277,7 @@ The following table lists the tools that are required for each diagram type, the
    |actdiag      |{uri-actdiag}[ActDiag]                                                |`actdiag`
    |blockdiag    |{uri-blockdiag}[BlockDiag]                                            |`blockdiag`
    |ditaa        |{uri-java}[Java]                                                      |`java`
+   |erd          |{uri-erd}[Erd]                                                        |`erd`
    |graphviz     |{uri-graphviz}[GraphViz]                                              |`dot` or `graphvizdot`
    |meme         |{uri-imagemagick}[ImageMagick]                                        |`convert` and `identify`
    |mermaid      |{uri-mermaid}[Mermaid]                                                |`mermaid`

lib/asciidoctor-diagram.rb

@@ -1,5 +1,6 @@
 require_relative 'asciidoctor-diagram/blockdiag'
 require_relative 'asciidoctor-diagram/ditaa'
+require_relative 'asciidoctor-diagram/erd'
 require_relative 'asciidoctor-diagram/graphviz'
 require_relative 'asciidoctor-diagram/meme'
 require_relative 'asciidoctor-diagram/mermaid'

lib/asciidoctor-diagram/erd.rb

@@ -0,0 +1,7 @@
+require_relative 'extensions'
+
+Asciidoctor::Extensions.register do
+  require_relative 'erd/extension'
+  block Asciidoctor::Diagram::ErdBlockProcessor, :erd
+  block_macro Asciidoctor::Diagram::ErdBlockMacroProcessor, :erd
+end

lib/asciidoctor-diagram/erd/extension.rb

@@ -0,0 +1,42 @@
+require_relative '../extensions'
+require_relative '../util/cli_generator'
+require_relative '../util/platform'
+require_relative '../util/which'
+
+module Asciidoctor
+  module Diagram
+    # @private
+    module Erd
+      include Which
+
+      def self.included(mod)
+        [:png, :svg].each do |f|
+          mod.register_format(f, :image) do |parent, source|
+            erd(parent, source, f)
+          end
+        end
+      end
+
+      def erd(parent, source, format)
+        erd_path = which(parent, 'erd')
+        dot_path = which(parent, 'dot', :alt_attrs => ['graphvizdot'])
+
+        dot_code = CliGenerator.generate_stdin(erd_path, format.to_s, source.to_s) do |tool_path, output_path|
+          [tool_path, '-o', Platform.native_path(output_path), '-f', 'dot']
+        end
+
+        CliGenerator.generate_stdin(dot_path, format.to_s, dot_code) do |tool_path, output_path|
+          [tool_path, "-o#{Platform.native_path(output_path)}", "-T#{format.to_s}"]
+        end
+      end
+    end
+
+    class ErdBlockProcessor < Extensions::DiagramBlockProcessor
+      include Erd
+    end
+
+    class ErdBlockMacroProcessor < Extensions::DiagramBlockMacroProcessor
+      include Erd
+    end
+  end
+end