Link to markdown title with special characters #955

[hoorelbeke-jimmy]

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Summary

I am displaying with streamlit some content, and I would like to display some links to markdown titles present on the streamlit page. For instance, the following is working:

import streamlit as st

st.markdown("# Introduction")
st.markdown("display some large text content")
st.markdown("[link](#introduction)") # does work

When I click on link, I return to the beginning of the section Introduction. However, this doesn't work when I use special characters in my title, for instance:

import streamlit as st

st.markdown("# Présentation")
st.markdown("display some large text content")
st.markdown("[link](#présentation)") # doesn't work
st.markdown("[link](#presentation)") # doesn't work either

To better understand the issue, I clicked on the anchor link on the left of the title "# Présentation", and I see on the URL that the link is "78e1d857" (for "# Introduction" it was "introduction").

Why?

My goal would be to be able to generate a link to the section "# Présentation" within my streamlit page, and for this I need to understand why the anchor link is "78e1d857". I tried to reverse engineer how to get this link based on the title content by looking at GitHub Flavored markdown, but I didn't find a way to do so.

How?

A method in the streamlit package that returns the anchor link based on a makdown title would be even better, for instance:

import streamlit as st

title = "Présentation"
st.markdown(f"#{title}")
st.markdown(f"[link](#{st.get_link_from_title(title)})")

Additional Context

No response

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[snehankekre]

I'm unsure if this is a bug in how we handle anchors in markdown, or if it is expected behavior. Out of caution, marking this as a bug to be triaged by Eng, who can make the determination whether this should instead be an enhancement request.

[sfc-gh-wihuang]

Hi, This is actually expected behavior: https://www.w3.org/TR/PR-html40-971107/struct/links.html#h-12.2.1

I recommend just using regular ascii characters.

A workaround you could do is using st.title and setting an anchor and that could possibly resolve your issue but it's not recommended .

[hoorelbeke-jimmy]

Actually I can't use only ascii characters. Indeed, most languages except English (French in my case) use accents which are not ascii characters. I completely understand that you can't use those characters directly in the URL, but I'm just asking how I can generate a valid URL that points to a title with special characters.
As I explained it in my original post, this URL exists, since "# Présentation" has an anchor link "78e1d857". There must be a place in streamlit source code where this title is converted into this hash to generate the link. Could please help me to find this code ?

[sfc-gh-wihuang]

Hi @hoorelbeke-jimmy ,

Can you try using:
st.title("Présentation", anchor="Présentation")
?

[hoorelbeke-jimmy]

Thanks it works, but why did you say it is not recommended ?

[sfc-gh-wihuang]

Hi @hoorelbeke-jimmy , it's not recommended because https://www.w3.org/TR/PR-html40-971107/struct/links.html#h-12.2.1