drewsberry/katextest.rb

## katextest.rb
require 'execjs'

def convert(content)
    singledollar = /(?<![\$])\$([^$]+)\$(?!\$)/
    doubledollar = /\$\$([^$]+)\$\$/

    path_to_katex = "../public/js/katex.min.js"
    katexsrc = open(path_to_katex).read
    katex = ExecJS.compile(katexsrc)

    content = content.gsub(singledollar) { |eqn| match_single_dollar(katex, eqn) }
    content = content.gsub(doubledollar) { |eqn| match_double_dollar(katex, eqn) }

    return content
end

def eqn_to_html(katex, string)
    return katex.call("katex.renderToString", string)
end

def match_single_dollar(katex, match)
    return eqn_to_html(katex, match[1])
end

def match_double_dollar(katex, match)
    s = "\\displaystyle " + match[1]
    return "<div style='text-align: center;'>" + eqn_to_html(katex, s) + "</div>"
end

content = "This is some content with $ inline equations $ and $$ centred equations $$"

content = convert(content)

html = "<!DOCTYPE HTML>
<html>
<head>
<meta charset='utf-8'>
<link rel='stylesheet' type='text/css' href='../public/css/katex.min.css'>
</head>
<body>
" + content + "
</body>
</html>
"

File.open("TEST.html", "w") { |file| file.write(html) }
	require 'execjs'

	def convert(content)
	singledollar = /(?<![\$])\$([^$]+)\$(?!\$)/
	doubledollar = /\$\$([^$]+)\$\$/

	path_to_katex = "../public/js/katex.min.js"
	katexsrc = open(path_to_katex).read
	katex = ExecJS.compile(katexsrc)

	content = content.gsub(singledollar) { \|eqn\| match_single_dollar(katex, eqn) }
	content = content.gsub(doubledollar) { \|eqn\| match_double_dollar(katex, eqn) }

	return content
	end

	def eqn_to_html(katex, string)
	return katex.call("katex.renderToString", string)
	end

	def match_single_dollar(katex, match)
	return eqn_to_html(katex, match[1])
	end

	def match_double_dollar(katex, match)
	s = "\\displaystyle " + match[1]
	return "<div style='text-align: center;'>" + eqn_to_html(katex, s) + "</div>"
	end

	content = "This is some content with $ inline equations $ and $$ centred equations $$"

	content = convert(content)

	html = "<!DOCTYPE HTML>
	<html>
	<head>
	<meta charset='utf-8'>
	<link rel='stylesheet' type='text/css' href='../public/css/katex.min.css'>
	</head>
	<body>
	" + content + "
	</body>
	</html>
	"

	File.open("TEST.html", "w") { \|file\| file.write(html) }