Added bibtex filter to hide custom bibtex keywords from bib file output (alshedivat#652)

Author: tonnesfn

_config.yml

@@ -233,6 +233,7 @@ scholar:
 
   query: "@*"
 
+filtered_bibtex_keywords: [abbr, abstract, arxiv, bibtex_show, html, pdf, selected, supp, blog, code, poster, slides, website] # Filter out certain bibtex entry keywords used internally from the bib output
 
 # -----------------------------------------------------------------------------
 # Responsive WebP Images

_layouts/bib.html

@@ -153,7 +153,7 @@
           {% if entry.bibtex_show -%}
           <!-- Hidden bibtex block -->
           <div class="bibtex hidden">
-            {% highlight bibtex %}{{ entry.bibtex }}{% endhighlight %}
+            {% highlight bibtex %}{{ entry.bibtex | hideCustomBibtex }}{% endhighlight %}
           </div>
           {%- endif %}
         </div>

_plugins/hideCustomBibtex.rb

@@ -0,0 +1,15 @@
+ module Jekyll
+  module HideCustomBibtex
+    def hideCustomBibtex(input)
+	  keywords = @context.registers[:site].config['filtered_bibtex_keywords']
+
+	  keywords.each do |keyword|
+		input = input.gsub(/^.*#{keyword}.*$\n/, '')
+	  end
+
+      return input
+    end
+  end
+end
+
+Liquid::Template.register_filter(Jekyll::HideCustomBibtex)