multiple template engines causes errors in _data

[writeblankspace]

I'm following this: https://lume.land/docs/core/multiple-template-engines/

siteTitle: My Site
layout: page.vto
templateEngine: [vto, md]

For some reason this causes an error that doesn't tell me where I went wrong:

Changes detected:
- /4913
- /_data.yml
- /_data.yml~
TypeError: source.split is not a function
    at errorLine (https://deno.land/x/[email protected]/src/environment.ts:357:32)
    at Environment.createError (https://deno.land/x/[email protected]/src/environment.ts:311:34)
    at Environment.tokenize (https://deno.land/x/[email protected]/src/environment.ts:169:18)
    at Environment.compile (https://deno.land/x/[email protected]/src/environment.ts:128:25)
    at Environment.runString (https://deno.land/x/[email protected]/src/environment.ts:92:29)
    at VentoEngine.render (https://deno.land/x/[email protected]/plugins/vento.ts:99:38)
    at Renderer.render (https://deno.land/x/[email protected]/core/renderer.ts:216:32)
    at Renderer.renderPages (https://deno.land/x/[email protected]/core/renderer.ts:95:38)
    at eventLoopTick (ext:core/01_core.js:168:7)
    at async Site.#buildPages (https://deno.land/x/[email protected]/core/site.ts:632:5)

Doing this in the frontmatter works as expected, but not in a _data.yml file.

[writeblankspace]

Nevermind, I was able to set it in_config.ts to make sure only .md files are processed:

site.preprocess([".md"], (pages) => {
    for (const page of pages) {
        page.data.templateEngine = ["vto", "md"]
    }
});

[oscarotero]

Okay, thanks.
Anyway, this looks like a bug in the function to show the error in Vento. I'll take a look.

[oscarotero]

I'm not able to reproduce this. Can you give me an example of code that produces this error?

[writeblankspace]

So I have my _data.yml file from earlier:

siteTitle: My Site
layout: page.vto
templateEngine: [vto, md]

And having this index.page.js somewhere in the file system causes the error:

export default function* ({ search, paginate }) {
	// config
	const baseURL = "/tags";

	// set args
	const tags = search.values("tags", "category=blog");

	// yield the index
	yield {
		url: `${baseURL}/`,
		layout: "layouts/tagList.vto",
		title: "Tags",
		category: "list",
		tagArr: tags
	}

	for (const tag of tags) {
		// find all blogPages with that tag
		const blogPages = search.pages(`category=blog ${tag}`, "date=desc");
		const options = {
			url: (n) => n===1 ? `${baseURL}/${tag}/` : `${baseURL}/${tag}/page-${n}/`,
			size: 5
		};
		// paginate the tagPage
		for (const page of paginate(blogPages, options)) {
			yield {
				...page,
				title: `#${tag}`,
				layout: "layouts/tagPage.vto",
				baseURL: `${baseURL}/${tag}`,
				tag: tag
			}
		}
	}
}

[oscarotero]

Ah, got it. This is because _data.yml file applies to all pages, including index.page.js. So that page is rendered as vento, instead of js.

As a solution, you can create a folder to store your markdown files and place the _data.yml file inside this folder:

|_ posts/
   |_ _data.yml
   |_ post-1.md
   |_ post-2.md