--- author: - Mauro Bieg - John MacFarlane title: Customizing Pandoc --- This document provides a quick overview over the various ways to customize pandoc's output, with links to fuller documentation and some examples. ## Templates When the `-s`/`--standalone` option is used, pandoc will generate a standalone document rather than a fragment. For example, in HTML output this will include the `<head>` element; in LaTeX output, it will include the preamble. Pandoc comes with a default template for (almost) every output format. A template is a plain text file containing variables that are replaced by text generated by pandoc. For example, the variable `$body$` will be replaced by the document body, and `$title$` by the title from metadata. To look at the default template for an output format, you can do `pandoc -D FORMAT`, where `FORMAT` is replaced by the name of the format. For example `pandoc -D latex`. You can also use your own template instead, either by using the `--template` option or by putting the custom template in your user data directory (on Linux and macOS, `~/.pandoc/templates/`). Note that in many cases you can avoid the need for a custom template by including a file with the `--include-in-header`, `--include-before-body`, or `--include-after-body` option. Or you can set the corresponding template variable directly. ### Template variables There are several ways to set template variables: | | [`--variable`] | [`--metadata`] | [YAML metadata] and [`--metadata-file`] | |:---------------|:------------------|:------------------|:----------------------------| | values can be… | strings and bools | strings and bools | also YAML objects and lists | | strings are… | inserted verbatim | escaped | interpreted as markdown | | accessible by filters: | no | yes | yes | [`--variable`]: https://pandoc.org/MANUAL.html#option--variable [`--metadata`]: https://pandoc.org/MANUAL.html#option--metadata [YAML metadata]: https://pandoc.org/MANUAL.html#extension-yaml_metadata_block [`--metadata-file`]: https://pandoc.org/MANUAL.html#option--metadata-file For more information, see [Templates](https://pandoc.org/MANUAL.html#templates) in the pandoc manual. ### Example: adding structured author data to HTML TODO ### Example: generating documents from YAML metadata TODO <!-- Example of generating a structured document, say, a table, from structured YAML metadata using just the control structures in pandoc's template language. --> ## Reference docx/pptx/odt For `docx`, `pptx` or `odt` documents, things are a bit more complicated. Instead of a single template file, you need to provide a customized `reference.docx/pptx/odt`. See the manual for the [`--reference-doc`](https://pandoc.org/MANUAL.html#option--reference-doc) option. ### Example: changing the font and line spacing in a Word docx TODO ## Filters Templates are very powerful, but they are only a sort of scaffold to place your document's body text in. You cannot directly change the body text using the template. If you need to affect the output of the actual body text, you can use a pandoc filter. A filter is a small program that transforms the document, between the parsing and the writing phase, while it is still in pandoc's native format. For example, a filter might find all the Header elements of a document and capitalize their text. Pandoc's native representation of a document is an abstract syntax tree (AST), not unlike the HTML DOM. It is documented [here](https://hackage.haskell.org/package/pandoc-types/docs/Text-Pandoc-Definition.html). A `Pandoc` document is a chunk of metadata (`Meta`) and a list of `Block`s. The `Block`s, in turn, are composed of other `Block`s and `Inline` elements. (`Block` elements are things like paragraphs, lists, headers, and code blocks. `Inline` elements are individual words, links, emphasis, and so on.) Filters operate on these elements. You can use `pandoc -t native` to learn about the AST's structure. There are two kinds of filters: JSON filters (which transform a JSON serialization of the pandoc AST, and may be written in any language that can parse and emit JSON), and Lua filters (which use an interface built directly into pandoc, and must be written in the Lua language). If you are writing your own filters, it is best to use Lua filters, which are more portable (they require only pandoc itself) and more efficient. See [Lua filters](https://pandoc.org/lua-filters.html) for documentation and examples. If you would prefer to write your filter in another language, see [Filters](https://pandoc.org/filters.html) for a gentle introduction to JSON filters. There's a repository of lua filters at [pandoc/lua-filters](https://github.com/pandoc/lua-filters) on GitHub. A number of pandoc filters, written in Haskell, are available on [Hackage](https://hackage.haskell.org/packages/search?terms=pandoc+filter) and can be installed using the `stack` or `cabal` tools. The wiki also lists [third party filters](https://github.com/jgm/pandoc/wiki/Pandoc-Filters). ### Example: capitalizing headers TODO ### Example: code extractor TODO ## Generic Divs and Spans TODO [Divs and Spans](https://pandoc.org/MANUAL.html#divs-and-spans): generic blocks that can be transformed with filters ### Example: colored text ### Example: custom styles in docx [Custom Styles in Docx](https://pandoc.org/MANUAL.html#custom-styles-in-docx) ## Raw attributes TODO [Generic raw attributes](https://pandoc.org/MANUAL.html#generic-raw-attribute): to include raw snippets ## Custom writers TODO [Custom writers](https://pandoc.org/MANUAL.html#custom-writers) ## Custom syntax highlighting TODO [Custom syntax highlighting](https://pandoc.org/MANUAL.html#syntax-highlighting), provided by the [skylighting library](https://github.com/jgm/skylighting) including highlighting styles