forgejo/docs/content/doc/advanced/external-renderers.en-us.md

date	title	slug	weight	toc	draft	menu
2018-11-23:00:00+02:00	External renderers	external-renderers	40	true	false	sidebar parent name weight identifier advanced External renderers 40 external-renderers

Custom files rendering configuration

Gitea supports custom file renderings (i.e., Jupyter notebooks, asciidoc, etc.) through external binaries, it is just a matter of:

• installing external binaries
• add some configuration to your app.ini file
• restart your Gitea instance

This supports rendering of whole files. If you want to render code blocks in markdown you would need to do something with javascript. See some examples on the Customizing Gitea page.

Installing external binaries

In order to get file rendering through external binaries, their associated packages must be installed. If you're using a Docker image, your Dockerfile should contain something along this lines:

FROM gitea/gitea:{{< version >}}
[...]

COPY custom/app.ini /data/gitea/conf/app.ini
[...]

RUN apk --no-cache add asciidoctor freetype freetype-dev gcc g++ libpng python-dev py-pip python3-dev py3-pip py3-zmq
# install any other package you need for your external renderers

RUN pip3 install --upgrade pip
RUN pip3 install -U setuptools
RUN pip3 install jupyter matplotlib docutils 
# add above any other python package you may need to install

app.ini file configuration

add one [markup.XXXXX] section per external renderer on your custom app.ini:

[markup.asciidoc]
ENABLED = true
FILE_EXTENSIONS = .adoc,.asciidoc
RENDER_COMMAND = "asciidoctor -e -a leveloffset=-1 --out-file=- -"
; Input is not a standard input but a file
IS_INPUT_FILE = false

[markup.jupyter]
ENABLED = true
FILE_EXTENSIONS = .ipynb
RENDER_COMMAND = "jupyter nbconvert --stdout --to html --template basic "
IS_INPUT_FILE = true

[markup.restructuredtext]
ENABLED = true
FILE_EXTENSIONS = .rst
RENDER_COMMAND = rst2html.py
IS_INPUT_FILE = false

If your external markup relies on additional classes and attributes on the generated HTML elements, you might need to enable custom sanitizer policies. Gitea uses the bluemonday package as our HTML sanitizier. The example below will support KaTeX output from pandoc.

[markup.sanitizer]
; Pandoc renders TeX segments as <span>s with the "math" class, optionally
; with "inline" or "display" classes depending on context.
ELEMENT = span
ALLOW_ATTR = class
REGEXP = ^\s*((math(\s+|$)|inline(\s+|$)|display(\s+|$)))+

[markup.markdown]
ENABLED         = true
FILE_EXTENSIONS = .md,.markdown
RENDER_COMMAND  = pandoc -f markdown -t html --katex

You may redefine ELEMENT, ALLOW_ATTR, and REGEXP multiple times; each time all three are defined is a single policy entry. All three must be defined, but REGEXP may be blank to allow unconditional whitelisting of that attribute.

Once your configuration changes have been made, restart Gitea to have changes take effect.