# Displaying code changes and comments
**URL:** https://meta.discourse.org/t/displaying-code-changes-and-comments/136308
**Category:** Feature
**Created:** [December 17, 2019, 1:07pm UTC](https://meta.discourse.org/t/displaying-code-changes-and-comments/136308 "2019-12-17T13:07:37Z")
**Posts on this page:** 11
**Page:** 1
### Author:  [@pgr](https://meta.discourse.org/u/pgr)
#### Post date: [December 17, 2019, 1:07pm UTC](https://meta.discourse.org/t/displaying-code-changes-and-comments/136308/1 "2019-12-17T13:07:37Z")
This is a question of whether a feature exists (possibly as a plugin) or a feature request in case it doesn’t…
What I’m looking for is the ability to display something like this within Discourse Forum discussions:
Not just showing a bit of code with language-specific syntax highlighting (we already have this by introducing it with ```php, for example, and closing with ```).
What I want is to be able to **highlight** some line, perhaps **comment it** , and **show an edit** to the line. These are typically useful in any Forums discussing technical stuff where you advise changes to apply or point out, problematic areas.
Although we _do_ use GitHub for our project, I’m not specifically asking to show changes as they happen in GitHub, but rather something that can be input independently within Discourse - the above image is meant only as an example of how it could look.
---
### Author:  [@david](https://meta.discourse.org/u/david)
#### Post date: [December 17, 2019, 1:11pm UTC](https://meta.discourse.org/t/displaying-code-changes-and-comments/136308/2 "2019-12-17T13:11:45Z")
You can display diffs like this:
```diff
A normal line
- removed line
+ added line
```
````plaintext
```diff
A normal line
- removed line
+ added line
```
````
---
### Author:  [@pgr](https://meta.discourse.org/u/pgr)
#### Post date: [December 17, 2019, 1:23pm UTC](https://meta.discourse.org/t/displaying-code-changes-and-comments/136308/3 "2019-12-17T13:23:34Z")
Okay… that looks 🆒
Is there anyway of crossing that with language specific syntax highlighting?
The code looks so bland without it, and so great with it.
---
### Author:  [@david](https://meta.discourse.org/u/david)
#### Post date: [December 17, 2019, 1:25pm UTC](https://meta.discourse.org/t/displaying-code-changes-and-comments/136308/4 "2019-12-17T13:25:36Z")
Unfortunately not - I agree it would be nice though. We use highlight.js for our syntax highlighting. It looks like there was a similar discussion [on their github repo](https://github.com/highlightjs/highlight.js/issues/480), but they decided it was out of scope for the project.
---
### Author:  [@pgr](https://meta.discourse.org/u/pgr)
#### Post date: [December 17, 2019, 1:55pm UTC](https://meta.discourse.org/t/displaying-code-changes-and-comments/136308/5 "2019-12-17T13:55:25Z")
Hhmm 🤔
So they have that [gist snippet there](https://gist.github.com/choxi/6fa98f7b203bf2dfdcfa), what they’re suggesting is that people implement that _outside_ the highlighter (in that case, it’s `marked.js`, I guess the same could be done with `highlight.js`).
Do you think Discourse could do that? Or, previous question, does this make sense in terms of architecture?
I guess the general idea is just to do some find-and-replace, remove the diff marks, send it to the syntax highlighter, and then work on it with some more find-and-replace afterwards. It sounds very awkward but the truth is that the snippet isn’t _that_ complicated at all.
---
### Author:  [@david](https://meta.discourse.org/u/david)
#### Post date: [December 17, 2019, 2:36pm UTC](https://meta.discourse.org/t/displaying-code-changes-and-comments/136308/6 "2019-12-17T14:36:13Z")
It’s certainly possible, but I don’t think it will be easy. All the syntax highlighting happens in javascript, so it could be manipulated using a theme component.
---
### Author:  [@Anatolia](https://meta.discourse.org/u/Anatolia)
#### Post date: [December 17, 2019, 7:29pm UTC](https://meta.discourse.org/t/displaying-code-changes-and-comments/136308/7 "2019-12-17T19:29:25Z")
How did you make them colored?
---
### Author:  [@david](https://meta.discourse.org/u/david)
#### Post date: [December 17, 2019, 7:30pm UTC](https://meta.discourse.org/t/displaying-code-changes-and-comments/136308/8 "2019-12-17T19:30:47Z")
Type out the code block like this:
````plaintext
```diff
A normal line
- removed line
+ added line
```
````
Specifying `diff` as the syntax means that you can use `+` and `-` at the beginning of lines to highlight them green and red.
---
### Author:  [@Anatolia](https://meta.discourse.org/u/Anatolia)
#### Post date: [December 17, 2019, 7:32pm UTC](https://meta.discourse.org/t/displaying-code-changes-and-comments/136308/9 "2019-12-17T19:32:58Z")
```diff
A normal line
- removed line
+ added line
```
I did it! Thank you @david
---
### Author:  [@pgr](https://meta.discourse.org/u/pgr)
#### Post date: [December 17, 2019, 8:15pm UTC](https://meta.discourse.org/t/displaying-code-changes-and-comments/136308/10 "2019-12-17T20:15:05Z")
I will be using the `diff` construct from now on, it’s helpful.
I don’t see Discourse implementing that other suggestion from the Gist, the more I think of this, the more I believe it would fit perfectly _inside_ the syntax highlighter, not outside.
Basically, as years go by it makes sense to add some features to syntax highlighters, and the basic job of _showing code in an easy to read way_ extends naturally to show also some of the code’s _dynamics_.
What changed, where, by whom; what am I pointing at; which helpful comment explains the relation of the code to the place where it is being posted, etc.
Thanks to everybody for their participation in this discussion.
---
### Author:  [@Mittineague](https://meta.discourse.org/u/Mittineague)
#### Post date: [December 18, 2019, 5:36am UTC](https://meta.discourse.org/t/displaying-code-changes-and-comments/136308/11 "2019-12-18T05:36:52Z")
Maybe an alternative?
```plaintext
del
ins
```
~~del~~
ins