Improved iframe handling: headers and footers are hidden when '?for_i…

…frame=true' is in the link parameters

README.md

@@ -17,7 +17,7 @@ bundle exec jekyll serve
 
 ## Enhancements
 
-Adding `?linktarget=top` to the URL for a page on this site will add `target="_top"` to each link on said page, allowing it to be used in a iframe with less wonkiness. This should allow smoother integration with Canvas once I get around to it.
+Adding `?for_iframe=true` to the URL for a page on this site will add `target="_top"` to each link on said page and hide the header and footer, allowing it to be used in a iframe with less wonkiness. This should allow smoother integration with Canvas once I get around to it.
 
 "Shell and Slurm Practice" is meh; it'd be nice to have a `find` thrown in there (plus material on `find`), and make it more open-ended and amenable to combining sed/grep/awk.
 

_includes/head.html

@@ -8,6 +8,14 @@
   {%- if jekyll.environment == 'production' and site.google_analytics -%}
     {%- include google-analytics.html -%}
   {%- endif -%}
+
+  <!--use MathJax to render formulas-->
   <script id="MathJax-script" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
+  <!--hide header and footer when the page is displayed in an iframe-->
+  <style>
+    body.hide-header-and-footer header {display: none; }
+    body.hide-header-and-footer footer {display: none; }
+  </style>
+  <!--JavaScript for iframe handling-->
   <script src="/sci-comp-course/assets/make-iframes-work.js"></script>
-</head>
+</head>

assets/make-iframes-work.js

@@ -1,13 +1,16 @@
 // Adds `target="_top" to every link on the page so that the page can be used by iframes if 'linktarget=top' is in the link parameters; for use with Canvas
 
 document.addEventListener('DOMContentLoaded', function () {
-    var UrlParams = new URLSearchParams(window.location.search);
-    if (UrlParams.get('linktarget') === 'top') {
+    const UrlParams = new URLSearchParams(window.location.search);
+    if (UrlParams.get('for_iframe') === 'true') {
+        // Add target="_top" to links
         var links = document.getElementsByTagName('a');
         for(var i=0; i<links.length; i++) {
             if (!links[i].hasAttribute('target')) {
                 links[i].target = '_top';
             }
         }
+        // Hide header and footer
+        document.body.classList.add('hide-header-and-footer')
     }
-});
+});