Blog Tech Notes

Installation

(1) Local run needs ruby 2.6 installed on PC

(2) Open ruby cmd.exe, and run “gem install bundler:2.1.4”

(3) Run “bundle install”

(4) Run “bundle exec jekyll serve –incremental”

Jekyll Documentation

You’ll find this post in your _posts directory. Go ahead and edit it and re-build the site to see your changes. You can rebuild the site in many different ways, but the most common way is to run jekyll serve, which launches a web server and auto-regenerates your site when a file is updated.

Jekyll requires blog post files to be named according to the following format:

YEAR-MONTH-DAY-title.MARKUP

Where YEAR is a four-digit number, MONTH and DAY are both two-digit numbers, and MARKUP is the file extension representing the format used in the file. After that, include the necessary front matter. Take a look at the source for this post to get an idea about how it works.

Jekyll also offers powerful support for code snippets:

def print_hi(name)
  puts "Hi, #{name}"
end
print_hi('Tom')
#=> prints 'Hi, Tom' to STDOUT.

Check out the Jekyll docs for more info on how to get the most out of Jekyll. File all bugs/feature requests at Jekyll’s GitHub repo. If you have questions, you can ask them on Jekyll Talk.

Tips and TroubleShooting

I mainly follow the steps in https://www.kiltandcode.com/2020/04/30/how-to-create-a-blog-using-jekyll-and-github-pages-on-windows/.

The only thing that post missed is:

git remote add origin https://github.com/mathwo/mathwo.github.io.git

Command to run jekyll locally and automatically update posts and preview all drafts (but you may need Ctrl-F5 to force cleaning Chrome cache) and change default port 4000

jekyll serve --livereload --drafts --port 4001

and after installing jekyll-TeXt theme:

bundle exec jekyll serve --incremental

Following error reported from command line when running “jekyll serve –livereload –trace”

Unable to load the EventMachine C extension; To use the pure-ruby reactor, require 'em/pure_ruby'

Solution:

https://github.com/oneclick/rubyinstaller2/issues/96

gem uninstall eventmachine
gem install eventmachine --platform ruby

Front Matter and VSCode Extensions:

https://insujang.github.io/2019-09-28/jekyll-vscode/

  1. VScode insider - this is an insider version of VSCode
  2. Docker Jekyll - this is a docker Jekyll image…
  3. jekyll-post plugin

MathJax support (this item is bypassed after adapting to TeXt theme)

http://sgeos.github.io/github/jekyll/2016/08/21/adding_mathjax_to_a_jekyll_github_pages_blog.html

This is a bit tricky for new Jekyll versions since it’s using Gem based themes and layouts are inside theme now.

First need locate theme minima files by following command in local repo folder:

bundle info minima

Then create a folder named _layouts and copy all html files from minima subfolder _layouts, then add following code inside post.html:

  <style>
    code.has-jax {
      font: inherit;
      font-size: 100%;
      background: inherit;
      border: inherit;
      color: #515151;
    }
  </style>

  <script type="text/javascript">
    MathJax = {
      tex: {
        inlineMath: [['$', '$'], ['\\(', '\\)']]
      }
    };
  </script>

  <script type="text/javascript" async
    src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-chtml.js">
  </script>

Install jekyll-TeXt theme

I fork the jekyll-TeXt repo and move contents into it to rebuild this blog. I feel it worths as it’s much better with quite some features I really like. Note: the MathJax.Hub.Config in jekyll-TeXt theme is not good enough. To use line-break \ we need display math sign $. Replace it with above code.


Generate anchor for each header

https://blog.briandrupieski.com/generate-anchors-in-jekyll-blog-post


favicon creation

Follow instruction in this link to update logo and favicon.ico.


Upload large PDF files

Note: LFS is not supported for public fork repo of GitHub. Solution: duplicate the repo can solve this issue.

Git Large File Storage has to be used if file size is larger than 100MB for GitHub. The trick is, after installing git-lfs program, all git lfs commands needs to be run at repo root directory:

git lfs install
git lfs track "*.pdf"
git add .gitattibutes

Note: lfs uploading always breaks PDF files. I split PDF files to be smaller than 100MB so LFS can be bypassed. LFS is buggy and do not use it if possible. Use following commands to remove cached files and uninstall lfs.

git lfs uninstall
git lfs ls-files
git rm --cached each_file_name_listed
rm .gitattribute
git commit -m "restore files from lfs"

Add GitLab repo mirror to be GitLab page site

This step is quite straight forward. Create group in GitLab mirror the github repo and then add a .gitlab-cli.yml on gitlab site and choose Jekyll template. Run a pipeline to deploy the site. Also removed github and email from _includes/footer.html.


Local run for the first time

  bundle install
  bundle exec jekyll serve --livereload

This fix is done by adding following line to Front-matter in about.md

permalink=/about/

and update the link to /about/ in navigation.yml. Similar to archive.


Remove post introduction in cover page

This feature is good but I don’t need it for my cover page. This can be easily done in _layouts\home.html

articles:
  data_source: paginator.posts
  article_type: BlogPosting
  show_cover: false
  show_excerpt: false
  show_readmore: false
  show_info: false

Home page style tweaking

Comment out padding-top line and padding_bottom line for .items–divided class in _item.scss


Tweak horizontal line

Follow this link to revise _sass/common/classes/_horizontal-rules.scss file:

@mixin horizontal-rules() {
  // border-bottom: 1px dashed #8c8b8b;
  border-bottom: 1px dashed $text-color-l;
  &::after {
    content: '\002702';
    display: inline-block;
    position: relative;
    top: 21px;
    left: 40px;
    padding: 0 3px;
    background: #ffffff;
    color: $text-color-l;
    font-size: map-get($base, font-size-h3);
  }
}

.horizontal-rules {
  @include horizontal-rules();
}

Home page article list font too large

Change h2 to h4 in includes/artical-list.html:

<header><a href=""><h4 itemprop="headline" class="item__header"></h4></a></header>

Similarly,change h1 to h2 in _includes/article_header.html:

<header><h2></h2></header>

Change to Computer Modern font family

Mainly take the font-face code from: https://www.jamiddleton.com/jekyll/update/2019/03/31/jekyll-mathjax-cmuserif-mlblog.html, and add to _sass/common/_variables.scss. Search and download missing files in the code from google.

@font-face {
    font-family: "Computer Modern";
    src:
        url('/assets/css/cmunrm.otf') format("opentype"),
        url('/assets/css/cmunrm-webfont.eot'),
        url('/assets/css/cmunrm-webfont.eot?#iefix') format("embedded-opentype"),
        url('/assets/css/cmunrm-webfont.svg') format("svg"),
        url('/assets/css/cmunrm-webfont.woff') format("woff"),
        url('/assets/css/cmunrm-webfont.ttf') format("truetype");
}

Then add “Computer Modern” in font-family, and change font-size from 1rem to 1.1rem:

$base: (
  font-family:            ("Computer Modern", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif),
  font-family-code:       (Menlo, Monaco, Consolas, Andale Mono, lucida console, Courier New, monospace),

  font-size-root:         16px,
  font-size-root-sm:      14px,

  font-size-xl:           1.5rem,
  font-size-lg:           1.25rem,
  font-size:              1.1rem,

This is to add an item in _data/navigation.yml. Do some translation for Home. I geel the title is not so obvious to be clickable and people may need look for Home link.


Add comments to Posts

The simple free comment system Utteranc is used. Visitors need login Github to post comments.


Increase blockquote font size

In _sass/common/.article__content.scss:

  blockquote {
    padding-left: map-get($spacers, 3);
    font-size: map-get($base, font-size);

Filter on Tag for Cover Title Pages

Considering each cover title page get longer and longer, I decide to show only a specified collection of cover pages, and each cover page links to a simple index page. Posts are linked to index page by months.

This solution is done by using collection in Jekyll. And it is configured in _config.yml.

collections:
  coverpages:
    output: true
    permalink: /:collection/:name

and its layout is specified by following code:

defaults:
  - scope:
      path: ""
      type: posts
    values:
      layout: article
      sharing: true
      license: true
      aside:
        toc: true
      show_edit_on_github: true
      show_subscribe: true
      pageview: true
  - scope:
      path: ""
      type: coverpages
    values:
      layout: article
      sharing: false
      license: false
      aside:
        toc: false
      show_edit_on_github: false
      show_subscribe: false
      pageview: false

and change _layouts/home.html to use the collection as data_source:

articles:
  data_source: coverpages
  article_type: BlogPosting
  show_cover: false
  show_excerpt: false
  show_readmore: false
  show_info: false

Unsolved questions:

  • What is the URL link to collection page

Remove comment from index page

_config.yml:

defaults:
  - scope:
      path: ""
      type: posts
    values:
      layout: article
      sharing: true
      license: true
      aside:
        toc: true
      show_edit_on_github: true
      show_subscribe: true
      pageview: true
      show-comment: true
  - scope:
      path: ""
      type: coverpages
    values:
      layout: article
      sharing: false
      license: false
      aside:
        toc: false
      show_edit_on_github: false
      show_subscribe: false
      pageview: false
      show-comment: false

and in _includes/article-footer.html:

image-20201129113702707


Liquid Learning Resources


Add float “Back to Top” Button

Take Vanilla BTT. Save js to assets/global/ folder and add code to _includes/footer.html:

<script src="/assets/global/vanilla-back-to-top.min.js"></script>
<script>addBackToTop({
  diameter: 32,
  backgroundColor: 'rgb(255, 82, 82)',
  textColor: '#fff'
})</script>

It’s not perfect - needs two clicks on mobile screen, and cannot scroll to top-left.


Star Rating System

Note: This part does not work any more

It may use zetabase to create a star rating system, like comment system does.


Add google search to site

  • Followed this link, added meta in _includes/head.html.
  • Follow this link to add gem to Gemfile and run local serve command.
  • Follow this link to add sitemap.xml to Google Search Console.
  • Follow this link if the sitemap cannot be fetched.

Use \tag{number} to number equations

No need to set auto numbering since each post would start with specified number.


02/03/2021

Align equation blocks to left: Here

MathJax.Hub.Config({
    displayAlign: "left",
    displayIndent: "2em"
});

02/21/2021

Remove vertical scrollbar for table:

Add two lines on overflow-x and overflow-y from _sass\components_article-content.scss line 205:

  table {
    display: block;
    width: 100%;
    overflow-x: auto;
    overflow-y: hidden !important;
    border-collapse: collapse;
  }

02/25/2021

Resolve rake version due to security risk

Dependabot can't update vulnerable dependencies without a lockfile
The currently installed version can't be determined.

To resolve the issue add a supported lockfile (Gemfile.lock or gems.locked).

View logs or learn more about troubleshooting Dependabot errors.

1 rake vulnerability found in jekyll-text-theme.gemspec 10 hours ago
Remediation
Upgrade rake to version 12.3.3 or later. For example:

spec.add_dependency "rake", ">= 12.3.3"
or…
spec.add_development_dependency "rake", ">= 12.3.3"
Always verify the validity and compatibility of suggestions with your codebase.

Revised to update rake version on both dev and master branches. This version update reminds me that, a blog should cut down dependencies to minimum to survive decades.