invalid character in title produces dom error

[tripodsan]

Description
eg: https://theblog--adobe.hlx.page/en/publish/2019/05/07/adobe-summit-emea-2019.html

Exception during #16/use:html from /nodejsAction/KUMO2xpR/html.js:237146:
InvalidCharacterError: \"data-Thousands of experience-minded marketers from across Europe have converged in London this week for the annual Adobe Summit—The Digital Experience Conference. Among the topics\" did not match the Name production: Unexpected syntax in top
Line 1:
data-Thousands of experience-minded marketers from across Europe have converged in London this week for the annual Adobe Summit—The Digital Experience Conference. Among the topics
              ^^^" 

probably caused here:

helix-pipeline/src/utils/heading-handler.js

Line 41 in 65e50a3

el.properties.id = el.properties.id || headingIdentifier;

[trieloff]

Looks like we should fix GitHub slugger

[rofe]

It's not the slugger. It's either a bug in the unified markdown parser, or our way of handling sections.

The following markdown reproduces the error locally:

---

Lorem ipsum: dolor

---

---

The text in the first section will be interpreted as frontmatter, and we will try to append data-Lorem ipsum as an attribute to the div, which causes the error. Even if we sanitized the data before adding (which would probably be a good idea regardless), the resulting page output would be missing this text:

<div data-lorem-ipsum="dolor"></div>

This means that it's currently not possible in Helix to have section text containing : . As a workaround, you can simply enter an additional line break before the text.

I think it's incorrect to treat the above as frontmatter since there is an empty line after the ---, but I'm not sure how to proceed here...

[tripodsan]

<div data-lorem-ipsum="dolor"></div>

what's wrong with this ?

I think it's incorrect to treat the above as frontmatter since there is an empty line after the ---, but I'm not sure how to proceed here...

but then it's broken. there are no empty lines allowed in frontmatter:

helix-pipeline/src/html/remark-matter.js

Line 148 in ef1502c

* - There may be no empty line within the frontmatter block; not even lines

but for frontmatter at the beginning of the document, it's different:

helix-pipeline/src/html/remark-matter.js

Line 154 in ef1502c

* For frontmatter blocks at the beginning of the document, the rules are a bit

we could require that all matter must not contain empty lines....
@trieloff WDYT?

[rofe]

<div data-lorem-ipsum="dolor"></div>

what's wrong with this ?

The expected output of that would be

<div>Lorem ipsum: dolor</div>

but then it's broken. there are no empty lines allowed in frontmatter

👍

we could require that all matter must not contain empty lines....
@trieloff WDYT?

👍

[trieloff]

I think forbidding empty lines in matter is too harsh, as you might want to use empty lines to structure your YAML.

[rofe]

What about forbidding leading empty lines? So this

---
class: bla

foo: bar

---

would become YAML but

---

hey: you

---

would become HTML

[tripodsan]

I think forbidding empty lines in matter is too harsh, as you might want to use empty lines to structure your YAML.

but it's already like this in mid-matter...

[trieloff]

We have a bit more leeway in being restrictive with midmatter because it is a Helix invention. For frontmatter, let's be as gradual in changing things as possible, i.e. only disallow leading empty lines.