refactor to avoid errors when rendering locally

_includes/gh_default_branch.html → _includes/gh_variables.html

 {% comment %}
-identify the default branch of the GitHub repo for the lesson, to create the correct link for "Improve on GitHub"
+When rendering websites locally, `site.github.url` doesn't get resolved
+properly unless GitHub PAT are set up and available in the environment.
+This leads to warnings and errors when trying to serve the site locally.
+To work around this, we use the `jekyll.environment` variable which is set to
+`development` when rendering the site locally, and set to `production` on
+GitHub where `site.github.url` will be defined.
 {% endcomment %}
 
+{% if jekyll.environment == "production" %}
+
 {% comment %}
 First, get the name of the repository
 {% endcomment %}
@@ -17,3 +24,22 @@ of the metadata that is relevant to the present repository.
 Now, we can extract the default branch for the repo
 {% endcomment %}
 {% assign default_branch = repo_info[0].default_branch %}
+
+{% comment %}
+Other variables requested by the template
+{% endcomment %}
+{% assign repo_url = site.github.repository_url %}
+{% assign search_domain_url = site.github.url %}
+{% assign project_title = site.github.project_title %}
+{% assign source_branch = site.github.source.branch %}
+
+{% elsif jekyll.environment == "development" %}
+
+{% assign repo_name = "" %}
+{% assign repo_url = "" %}
+{% assign default_branch = "" %}
+{% assign search_domain_url = "" %}
+{% assign project_title = "" %}
+{% assign source_branch = "" %}
+
+{% endif %}

_includes/lesson_footer.html

@@ -2,7 +2,7 @@
   Footer for lesson pages.
 {% endcomment %}
 
-{% include gh_default_branch.html %}
+{% include gh_variables.html %}
 
 <footer>
   <div class="row">
@@ -30,17 +30,17 @@
     <div class="col-md-6 help-links" align="right">
 	{% if page.source %}
 	{% if page.source == "Rmd" %}
-	<a href="{{site.github.repository_url}}/edit/{{ default_branch }}/{{page.path|replace: "_episodes", "_episodes_rmd" | replace: ".md", ".Rmd"}}">Edit on GitHub</a>
+	<a href="{{repo_url}}/edit/{{ default_branch }}/{{page.path|replace: "_episodes", "_episodes_rmd" | replace: ".md", ".Rmd"}}">Edit on GitHub</a>
 	{% endif %}
 	{% else %}
-	<a href="{{site.github.repository_url}}/edit/{{ default_branch }}/{{page.path}}">Edit on GitHub</a>
+	<a href="{{repo_url}}/edit/{{ default_branch }}/{{page.path}}">Edit on GitHub</a>
 	{% endif %}
 	/
-	<a href="{{ site.github.repository_url }}/blob/{{ site.github.source.branch }}/CONTRIBUTING.md">Contributing</a>
+	<a href="{{ repo_url }}/blob/{{ source_branch }}/CONTRIBUTING.md">Contributing</a>
 	/
-	<a href="{{ site.github.repository_url }}/">Source</a>
+	<a href="{{ repo_url }}/">Source</a>
 	/
-	<a href="{{ site.github.repository_url }}/blob/{{ site.github.source.branch }}/CITATION">Cite</a>
+	<a href="{{ repo_url }}/blob/{{ source_branch }}/CITATION">Cite</a>
 	/
 	<a href="mailto:{{ site.email }}">Contact</a>
     </div>

_includes/links.md

+{% include gh_variables.html %}
+
 [cc-by-human]: https://creativecommons.org/licenses/by/4.0/
 [cc-by-legal]: https://creativecommons.org/licenses/by/4.0/legalcode
 [ci]: http://communityin.org/
@@ -5,7 +7,7 @@
 [coc]: https://docs.carpentries.org/topic_folders/policies/code-of-conduct.html
 [concept-maps]: https://carpentries.github.io/instructor-training/05-memory/
 [contrib-covenant]: https://contributor-covenant.org/
-[contributing]: {{ site.github.repository_url }}/blob/gh-pages/CONTRIBUTING.md
+[contributing]: {{ repo_url }}/blob/{{ source_branch }}/CONTRIBUTING.md
 [cran-checkpoint]: https://cran.r-project.org/package=checkpoint
 [cran-knitr]: https://cran.r-project.org/package=knitr
 [cran-stringr]: https://cran.r-project.org/package=stringr

_includes/navbar.html

@@ -2,7 +2,7 @@
   Lesson navigation bar.
 {% endcomment %}
 
-{% include gh_default_branch.html %}
+{% include gh_variables.html %}
 
 <nav class="navbar navbar-default">
   <div class="container-fluid">
@@ -77,10 +77,10 @@
         <li><a href="{{ relative_root_path }}{% link LICENSE.md %}">License</a></li>
 	{% if page.source %}
 	{% if page.source == "Rmd" %}
-	<li><a href="{{site.github.repository_url}}/edit/{{ default_branch }}/{{page.path|replace: "_episodes", "_episodes_rmd" | replace: ".md", ".Rmd"}}">Improve this page <span class="glyphicon glyphicon-pencil" aria-hidden="true"></span></a></li>
+	<li><a href="{{repo_url}}/edit/{{ default_branch }}/{{page.path|replace: "_episodes", "_episodes_rmd" | replace: ".md", ".Rmd"}}">Improve this page <span class="glyphicon glyphicon-pencil" aria-hidden="true"></span></a></li>
 	{% endif %}
 	{% else %}
-	<li><a href="{{site.github.repository_url}}/edit/{{ default_branch}}/{{page.path}}">Improve this page <span class="glyphicon glyphicon-pencil" aria-hidden="true"></span></a></li>
+	<li><a href="{{repo_url}}/edit/{{ default_branch}}/{{page.path}}">Improve this page <span class="glyphicon glyphicon-pencil" aria-hidden="true"></span></a></li>
 	{% endif %}
       </ul>
       <form class="navbar-form navbar-right" role="search" id="search" onsubmit="google_search(); return false;">

_layouts/base.html

 ---
 ---
-{% comment %}
-When rendering websites locally, `site.github.url` doesn't get resolved
-properly unless GitHub PAT are set up and available in the environment.
-This leads to warnings and errors when trying to serve the site locally.
-To work around this, we use the `jekyll.environment` variable which is set to
-`development` when rendering the site locally, and set to `production` on
-GitHub where `site.github.url` will be defined.
-{% endcomment %}
-
-{% if jekyll.environment == "development" %}
-{% assign search_domain_url = "" %}
-{% elsif jekyll.environment == "production" %}
-{% assign search_domain_url = site.github.url  %}
-{% endif %}
-
 {% include base_path.html %}
+{% include gh_variables.html %}
 
 <!doctype html>
 <html lang="en">

_layouts/workshop.html

 ---
 ---
-
 {% include base_path.html %}
+{% include gh_variables.html %}
 
 <!doctype html>
 <html lang="en">
   <head>
 
-    <meta name="slug" content="{{site.github.project_title}}" />
+    <meta name="slug" content="{{project_title}}" />
     <meta name="startdate" content="{{page.startdate}}" />
     <meta name="enddate" content="{{page.enddate}}" />
     <meta name="humandate" content="{{page.humandate}}" />