Adding support for stem equations (#24)

* Adding support for stem equations

* added test cases

_includes/script.html

@@ -13,7 +13,22 @@
     };
 
     var replace_math_symb = function(s){
-      return s.replace(/(`[^`]+`)/g, '<<math_symbol>>');
+        // replace mathjax
+        mathjax_containers = s.querySelectorAll('math, mjx-container');
+
+        if(mathjax_containers.length > 0) {
+            s = s.cloneNode(true);
+            s.querySelectorAll('math, mjx-container').forEach(container => {
+                container.replaceWith('<<math_symbol>>');
+            });
+        }
+
+        text = s.innerText;
+
+        // replace asciimath
+        text = text.replace(/(`[^`]+`)/g, '<<math_symbol>>');
+
+        return text;
     };
 
     var copyBtn = d.getElementById('engTermCopy');
@@ -43,7 +58,7 @@
         for (var _elm of elmsToCopy) {
             if (_elm.innerText.trim().length > 0) {
                 // textToCopy = textToCopy + _elm.innerText + '\r\n\r\n';
-                textToCopy = textToCopy + replace_math_symb(_elm.innerText) + '\r\n\r\n';
+                textToCopy = textToCopy + replace_math_symb(_elm) + '\r\n\r\n';
             };
         };
 

jekyll-geolexica.gemspec

@@ -47,6 +47,8 @@ Gem::Specification.new do |spec|
   # Pin logger to <= 1.5.3 due to incompatibility of logger 1.6.0 with Jekyll 4.3.2
   spec.add_runtime_dependency "logger", "<= 1.5.3"
   spec.add_runtime_dependency "relaton"
+  spec.add_runtime_dependency "unitsml"
+  spec.add_runtime_dependency "plurimath"
 
   # Zeitwerk::Loader#push_dir supports :namespace argument from v. 2.4.
   spec.add_runtime_dependency "zeitwerk", "~> 2.4"

lib/jekyll/geolexica.rb

@@ -3,6 +3,7 @@
 
 require "jekyll"
 require "glossarist"
+require "plurimath"
 
 module Jekyll
   module Geolexica

lib/jekyll/geolexica/hooks.rb

@@ -11,6 +11,7 @@ def register_all_hooks
         hook :post_read, :site, :load_glossary
         hook :pre_render, :documents, :expose_glossary
         hook :pre_render, :pages, :expose_glossary
+        hook :post_render, :pages, :convert_math
       end
 
       # Adds Jekyll::Site#glossary method, and initializes an empty glossary.
@@ -28,6 +29,26 @@ def expose_glossary(page_or_document, liquid_drop)
         liquid_drop["glossary"] = page_or_document.site.glossary
       end
 
+      def convert_math(page)
+        page.output.gsub!(/stem:\[([^\]]*?)\]/) do
+          ascii_equation = CGI.unescapeHTML(Regexp.last_match[1])
+
+          mathml_equation = ::Plurimath::Math
+                              .parse(ascii_equation, :asciimath)
+                              .to_mathml
+
+          # temporary hack to use display inline for math equations because
+          # currently there is no option to use display inline in plurimath
+          mathml_equation.gsub!("display=\"block\"", "display=\"inline\"")
+
+          # Removing newlines(\n) and escaping double quotes(")
+          # because they will cause parsing issues in json
+          mathml_equation.gsub!("\n", "").gsub!("\"", "\\\"") unless page.html?
+
+          mathml_equation
+        end
+      end
+
       def hook event, target, action
         Jekyll::Hooks.register target, event, &method(action)
       end

spec/unit/jekyll/geolexica/hooks_spec.rb

@@ -0,0 +1,70 @@
+# (c) Copyright 2020 Ribose Inc.
+#
+
+RSpec.describe ::Jekyll::Geolexica::Hooks do
+  subject do
+    w = Object.new
+    w.extend(described_class)
+    w
+  end
+
+  let(:page) do
+    instance_double(
+      Jekyll::Geolexica::ConceptPage::HTML,
+      output: page_output,
+      html?: is_html,
+    )
+  end
+
+  describe ".convert_math" do
+    context "when page is HTML" do
+      let(:is_html) { true }
+
+      let(:page_output) do
+        "foo stem:[a_2] bar"
+      end
+
+      let(:expected_output) do
+        <<~OUTPUT.strip
+          foo <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline">
+            <mstyle displaystyle="true">
+              <msub>
+                <mi>a</mi>
+                <mn>2</mn>
+              </msub>
+            </mstyle>
+          </math>
+           bar
+        OUTPUT
+      end
+
+      it "should convert stem:[] to MathML" do
+        expect { subject.send(:convert_math, page) }
+          .to change { page.output }
+          .from(page_output)
+          .to(expected_output)
+      end
+    end
+
+    context "when page is not HTML" do
+      let(:is_html) { false }
+
+      let(:page_output) do
+        "foo stem:[a_2] bar"
+      end
+
+      let(:expected_output) do
+        <<~OUTPUT.strip
+          foo <math xmlns=\\"http://www.w3.org/1998/Math/MathML\\" display=\\"inline\\">  <mstyle displaystyle=\\"true\\">    <msub>      <mi>a</mi>      <mn>2</mn>    </msub>  </mstyle></math> bar
+        OUTPUT
+      end
+
+      it "should convert stem:[] to MathML" do
+        expect { subject.send(:convert_math, page) }
+          .to change { page.output }
+          .from(page_output)
+          .to(expected_output)
+      end
+    end
+  end
+end