Line Highlighting in html code block

[aborruso]

Hi,
for reveal output, I can use {.python code-line-numbers="7,9"} to highlight line 7 and 9.

If use it for a block code in an HTML output, I have no highlight for those lines.
Is there a way to do it also for HTML output?

Thank you

[mcanouil]

I am not sure there is an easy way right now ...
The code line highlighting is a Reveal.js feature.
It could be ported to standard HTML format in theory, thus a feature request to Quarto team.

[aborruso]

What's the best way to create a feature request? Here in discussions or a new issue?

[mcanouil]

I do not know if there is official/preferred way, but currently there is two approaches:

• Wait for a Quarto team member to see this discussion, he will discuss it with the team, then if that's something they'll consider doing, they'll create an issue (feature request) from this discussion.
• Don't wait and open an issue with usually a tag in the title such as "[FR]" or "[Feature Request]" which describes as best as you can what you would like and possible hints/solutions to do that.

[shafayetShafee]

I have created a small Quarto filter extension line-highlight to enable line highlighting (both for source code and output) in HTML output format (i.e. format: html).

To highlight a specific line of source code, you need to use the chunk option source-line-numbers which takes values similarly as code-line-numbers. Note that, this filter extension requires Quarto v1.2 at least to work.

An example,

---
title: "Line Highlighting in HTML"
format: html
filters: 
  - line-highlight
jupyter: python3
---

```{python}
#| source-line-numbers: "3"
#| class-source: "numberLines"

import numpy as np

r = np.arange(0, 2, 0.01)
theta = 2 * np.pi * r
```

See the github repository for more examples and the installation process.

[aborruso]

Thank you @shafayetShafee