bench-forgejo/docs/content/doc/advanced/external-renderers.en-us.md
6543 640066840e
Use a generic markup class to display externally rendered files and diffs (#15735)
* creates and implements generic markup less class

* How to give custom CSS to externally rendered html

* Clarifies sources of CSS styling of markup

* further clarification of sources of markup styling

* rename _markdown to _markup

* remove defunct import

* fix orphaned reference

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

* more renames markdown -> markup

* do not suggest less customization

* add back tokens

* fix class whitespace, remove useless if-clause

* remove unused csv-data rules

* use named exports and rename functions

* sort imports

Co-authored-by: HarvsG <11440490+HarvsG@users.noreply.github.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: silverwind <me@silverwind.io>
2021-05-07 10:43:41 +02:00

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---
date: "2018-11-23:00:00+02:00"
title: "External renderers"
slug: "external-renderers"
weight: 40
toc: false
draft: false
menu:
sidebar:
parent: "advanced"
name: "External renderers"
weight: 40
identifier: "external-renderers"
---
# Custom files rendering configuration
**Table of Contents**
{{< toc >}}
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](../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:
```docker
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 libffi-dev py-pip python3-dev py3-pip py3-pyzmq
# install any other package you need for your external renderers
RUN pip3 install --upgrade pip
RUN pip3 install -U setuptools
RUN pip3 install jupyter 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`:
```ini
[markup.asciidoc]
ENABLED = true
FILE_EXTENSIONS = .adoc,.asciidoc
RENDER_COMMAND = "asciidoctor -s -a showtitle --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 = "timeout 30s pandoc +RTS -M512M -RTS -f rst"
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`](https://godoc.org/github.com/microcosm-cc/bluemonday) package as our HTML sanitizier. The example below will support [KaTeX](https://katex.org/) output from [`pandoc`](https://pandoc.org/).
```ini
[markup.sanitizer.TeX]
; 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 must define `ELEMENT`, `ALLOW_ATTR`, and `REGEXP` in each section.
To define multiple entries, add a unique alphanumeric suffix (e.g., `[markup.sanitizer.1]` and `[markup.sanitizer.something]`).
Once your configuration changes have been made, restart Gitea to have changes take effect.
**Note**: Prior to Gitea 1.12 there was a single `markup.sanitiser` section with keys that were redefined for multiple rules, however,
there were significant problems with this method of configuration necessitating configuration through multiple sections.
## Customizing CSS
The external renderer is specified in the .ini in the format `[markup.XXXXX]` and the HTML supplied by your external renderer will be wrapped in a `<div>` with classes `markup` and `XXXXX`. The `markup` class provides out of the box styling (as does `markdown` if `XXXXX` is `markdown`). Otherwise you can use these classes to specifically target the contents of your rendered HTML.
And so you could write some CSS:
```css
.markup.XXXXX html {
font-size: 100%;
overflow-y: scroll;
-webkit-text-size-adjust: 100%;
-ms-text-size-adjust: 100%;
}
.markup.XXXXX body {
color: #444;
font-family: Georgia, Palatino, 'Palatino Linotype', Times, 'Times New Roman', serif;
font-size: 12px;
line-height: 1.7;
padding: 1em;
margin: auto;
max-width: 42em;
background: #fefefe;
}
.markup.XXXXX p {
color: orangered;
}
```
Add your stylesheet to your custom directory e.g `custom/public/css/my-style-XXXXX.css` and import it using a custom header file `custom/templates/custom/header.tmpl`:
```html
<link type="text/css" href="{{AppSubUrl}}/css/my-style-XXXXX.css" />
```