Code Syntax Theming

[rafegoldberg]

Technical documentation features a lot of code blocks. We already allow authors to customize the base background and text colors for code blocks. We should extend this support to the complete syntax highlighting theme.

CSS-Based Themes

Using syntax selectors & highlight variables to override the default theme:

.markdown-body pre .cm {
  &-node        {  color:  var(--md-syntax-string,     #9c3328)  }
  &-tag         {  color:  var(--md-syntax-string,     #9c3328)  }
  &-string      {  color:  var(--md-syntax-string,     #b35e14)  }
  &-number      {  color:  var(--md-syntax-number,     #75438a)  }
  &-property    {  color:  var(--md-syntax-property,   #1d75b3)  }
  &-keyword     {  color:  var(--md-syntax-keyword,    #1d75b3)  }
  &-qualifier   {  color:  var(--md-syntax-qualifier,  #047d65)  }
  &-variable    {  color:  var(--md-syntax-var,        #047d65)  }
  &-variable-2  {  color:  var(--md-syntax-var-alt,    #ffffff)  }
  &-comment     {  color:  var(--md-syntax-comment,    #75787b)  }
  &-atom        {  color:  var(--md-syntax-atom,       #75438a)  }
  &-operator    {  color:  var(--md-syntax-operator,   #ffffff)  }
  &-def         {  color:  var(--md-syntax-def,        #ffffff)  }
}

Issues

• lots of manual Custom CSS config required (still, it's better than some of the crazy things I've seen done to get this working though!)
• will revert to default theme in older browsers (without a polyfill at least!)