💡 Feature Request - {% startmermaid %} block tag

[maiksprenger]

Implementation PR

No response

Reference Issues

No response

Summary

Hi, thank you for a neat little project!

At my work, we'd like to implement a few larger diagrams, and it's hard to format them in the single {% mermaid "" %} template tag. I propose a second, block template tag, and am happy to implement it if you think it's worth doing.

I would keep support for specifying theme and version, and I'd update the existing tests to test them with both versions of the tag. The resulting output should be identical, apart from maybe whitespace differences.

What do you think?

Basic Example

{% startmermaid %}
graph TD
    A[Enter Chart Definition] --> B(Preview)
    B --> C{decide}
    C --> D[Keep]
    C --> E[Edit Definition]
    E --> B
    D --> F[Save Image and Code]
    F --> B
{% endmermaid %}

Drawbacks

• block template tag code is more complex than simple tags

Unresolved questions

• How would we call the new template tags? startmermaid/endmermaid? mermaid_block/endmermaid_block? diagram/enddiagram? Or would we try to be clever and support both versions with a single mermaid tag?

[ArtyomVancyan]

I propose a second, block template tag, and am happy to implement it if you think it's worth doing.

Sounds good! I also like the idea of start and end blocks for larger diagrams with the startmermaid/endmermaid tag names. I will wait for your PR.

would we try to be clever and support both versions with a single mermaid tag?

I am not sure what you mean... Your changes shouldn't affect on the existing tags or their usage.

[maiksprenger]

Thanks for the speedy response. I'll get a PR ready.

I am not sure what you mean... Your changes shouldn't affect on the existing tags or their usage.

I was thinking aloud about making the mermaid tag smart enough to detect whether it's used as simple tag or as block tag with an end tag. That would let us give (IMHO) the best UX for users, but at the cost of considerable code complexity - block tags are already gnarly to write.

I'll instead go for a new tag startmermaid/endmermaid as suggested.

[ArtyomVancyan]

I see, but let's have both {% mermaid "" %} and startmermaid/endmermaid versions working.

[maiksprenger]

#19 was merged, so I'm delighted to be able to close this issue. Thanks again!