Parsing Markdown in ColdFusion

Welcome to my third, yes, third, ColdFusion post in 2024. Is it a trend? Who knows. That being said, I'm doing some prep work to update my presentation on Google Gemini in preparation for my talk at Adobe's ColdFusion Summit later this month, I'm updating my Node.js demos to ColdFusion and ran into an interesting issue - converting Markdown responses from Gemini to HTML.

My first quick Google searches didn't really mesh well with what I expected, so I asked on the CFML Slack and James Moberg pointed out a few options, but suggested I focus on Flexmark (which was backed up by another person on the Slack).

I was directed to a blog post by, of course, Ben Nadel: "Using Flexmark 0.32.24 To Parse Markdown Content Into HTML Output In ColdFusion". It was a bit out of date but was enough to get me going. Here's how I built my, admittedly quick and dirty, solution.

Step One - Get the Jar

The Flexmark library is a Java package that looks to be incredibly customizable and conplex. The install instructions expect you to use Maven or another Java tool, but I figured I just needed to get the right jar. This took me a minute to figure out. I ended up Maven at the latest release for the "all" package, which led to the file listing here: https://repo1.maven.org/maven2/com/vladsch/flexmark/flexmark-all/0.64.8/

On this page, I downloaded flexmark-all-0.64.8.lib.jar.

Step Two - Load the Jar

Next, I added it in my Application.cfc like so:

this.javaSettings = {
	loadPaths = ["./flexmark-all-0.64.8-lib.jar"]
};

I'd probably not put the jar in the root of my demo, but this isn't for production or anything.

Step Three - Use the Code

So for actually using it, I didn't follow Ben's code, but rather the simple Java code referenced in the GitHub repo. This is what they had:

package com.vladsch.flexmark.java.samples;
import com.vladsch.flexmark.html.HtmlRenderer;
import com.vladsch.flexmark.parser.Parser;
import com.vladsch.flexmark.util.ast.Node;
import com.vladsch.flexmark.util.data.MutableDataSet;
public class BasicSample {
    public static void main(String[] args) {
        MutableDataSet options = new MutableDataSet();
        // uncomment to set optional extensions
        //options.set(Parser.EXTENSIONS, Arrays.asList(TablesExtension.create(), StrikethroughExtension.create()));
        // uncomment to convert soft-breaks to hard breaks
        //options.set(HtmlRenderer.SOFT_BREAK, "<br />\n");
        Parser parser = Parser.builder(options).build();
        HtmlRenderer renderer = HtmlRenderer.builder(options).build();
        // You can re-use parser and renderer instances
        Node document = parser.parse("This is *Sparta*");
        String html = renderer.render(document);  // "<p>This is <em>Sparta</em></p>\n"
        System.out.println(html);
    }
}

And from this, I wrote up a quick demo:

ds = createObject("java", "com.vladsch.flexmark.util.data.MutableDataSet");
ps = createObject("java", "com.vladsch.flexmark.parser.Parser").builder(ds).build();
hm = createObject("java", "com.vladsch.flexmark.html.HtmlRenderer").builder(ds).build();
doc = ps.parse("This is *sparta*");
result = hm.render(doc);
writeoutput(result);

Yeah, not the best variable names, but, it worked perfectly well. I took this scratch code and built a simple UDF:

function toMarkdown(str) {
	var ds = createObject("java", "com.vladsch.flexmark.util.data.MutableDataSet");
	var ps = createObject("java", "com.vladsch.flexmark.parser.Parser").builder(ds).build();
	var hm = createObject("java", "com.vladsch.flexmark.html.HtmlRenderer").builder(ds).build();
	var doc = ps.parse(str);
	return hm.render(doc);
}

I feel like this would be better as a CFC cached in the App scope so I'm not re-creating the Java objects on every call, but I'll leave that for others to do. :)

I tested it like so, and it worked perfectly well:

<cfsavecontent variable="test">
# Hello World
Tell me why you love my [blog](https://www.raymondcamden.com).
This is another paragraph. 
## Stuff I like:
* Books
* Video Games
* Music 
* Beer 
</cfsavecontent>
<cfoutput>#toMarkdown(test)#</cfoutput>

I hope this helps! It will be in my repo for the presentation once I check it in, but let me know if you have any questions.