beamer writer doesn't output \hypertarget in header correctly

[Frefreak]

For this test snippet

# Header1 {#head1}

## abc {#abc}

text under abc

## def {#def}

text under def

link to [abc](#abc)

I want the link under def points to abc header, the beamer output this by invoking pandoc test.md -t beamer:

\section{Header1}\label{head1}

\begin{frame}{abc}

text under abc

\end{frame}

\begin{frame}{def}

text under def

link to \protect\hyperlink{abc}{abc}

\end{frame}

the generated pdf does contains a link but when clicked it redirects to the first page. If I manually add \hypertarget{abc}{} before the \begin{frame}{abc} line and disable ignorenonframetext (which I know from this SO question) the link works as expected.

Is this behaviour expected? Is there any easier way without manually modifying generated latex code to achieve the same effects? The latex writer (-t latex) seems create the link correctly though.

[georgejean]

Hi,

it seems that

# Header1 {#head1}

## \hypertarget{abc}{abc}

text under abc

## \hypertarget{def}{def 1}

text under def

## \hypertarget{otherdef}{def 2}

link to [abc](#abc)

link to [def 1](#def)

does the job.

From Pandoc User's Guide:

Note, however, that this method of providing links to sections works only in HTML, LaTeX, and ConTeXt formats.
...
Internal links are currently supported for HTML formats (including HTML slide shows and EPUB), LaTeX, and ConTeXt.

[Frefreak]

Thanks! In this way the link points to the content under the header rather than the header itself (tried in okular), but this is totally acceptable.

[jgm]

Should this really be closed? This seems like a workaround; if there's a problem in pandoc, it should be fixed.

[Frefreak]

I didn't notice the username and thought that was the "official recommended solution" to this... Is it possible to make this work without inline latex code?

[georgejean]

According to the doc

Frame attributes in beamer
Sometimes it is necessary to add the LaTeX [fragile] option to a frame in beamer (for example, when using the minted environment). This can be forced by adding the fragile class to the header introducing the slide:

Fragile slide {.fragile}

All of the other frame attributes described in Section 8.1 of the Beamer User’s Guide may also be used: allowdisplaybreaks, allowframebreaks, b, c, t, environment, label, plain, shrink.

a more pandoc way to achieve this could be

# Header1 {#head1}

## abc {label=abc}

text under abc

## def 1 {label=def}

text under def

## otherdef

link to [abc](#abc)

link to [def 1](#def)

[alex-ball]

Note that, in normal HTML, LaTeX, and ConTeXt and in other slide outputs, links to headings of whatever level work as advertised. The same is true of Beamer output except for whatever heading level is selected as the slide level.

(Okay, for the above-slide-level links to work you have to remove [ignorenonframetext] from the class options.)

Surely it makes sense to routinely add the label attribute (with the auto-generated ID) to all frames in Beamer output to eliminate this inconsistency? It is something of a chore to ask the author to add them all manually for that one heading level...

[jgm]

@Frefreak - Disabling ignorenonframetext would have a number of other consequences which would amount to a breaking change.

For this reason @georgejean's approach, which puts the hypertarget inside the frame title, seems better. (Of course, pandoc should do this automatically rather than making the user put in raw latex.)

This should be an easy change; I'll put in in the pandoc 2.0 milestone.
For reference, here's what the latex would look like:

\begin{frame}{\hypertarget{abc}{abc}}

text under abc

\end{frame}

\begin{frame}{\hypertarget{def}{def 1}}

text under def

\end{frame}

\begin{frame}{\hypertarget{otherdef}{def 2}}

link to \protect\hyperlink{abc}{abc}

link to \protect\hyperlink{def}{def 1}

[Frefreak]

Thank you. At that time I would use {#abc} instead of {label = abc} right?

[jgm]

+++ Frefreak [Mar 15 17 18:23 ]:

Thank you. At that time I would use {#abc} instead of {label = abc} right?

Correct.