Content formats
You can put any file type into your /content directories, but Hugo uses the markup front matter value if set or the file extension (see Markup identifiers in the table below) to determine if the markup needs to be processed, e.g.:
- Markdown converted to HTML
- Shortcodes processed
- Layout applied
List of content formats
The current list of content formats in Hugo:
| Name | Markup identifiers | Comment |
|---|---|---|
| Goldmark | md, markdown, goldmark | Note that you can set the default handler of md and markdown to something else, see Configure Markup. |
| Emacs Org-Mode | org | See go-org. |
| AsciiDoc | asciidocext, adoc, ad | Needs Asciidoctor installed. |
| RST | rst | Needs RST installed. |
| Pandoc | pandoc, pdc | Needs Pandoc installed. |
| HTML | html, htm | To be treated as a content file, with layout, shortcodes etc., it must have front matter. If not, it will be copied as-is. |
The markup identifier is fetched from either the markup variable in front matter or from the file extension. For markup-related configuration, see Configure Markup.
External helpers
Some of the formats in the table above need external helpers installed on your PC. For example, for AsciiDoc files,
Hugo will try to call the asciidoctor command. This means that you will have to install the associated
tool on your machine to be able to use these formats.
Hugo passes reasonable default arguments to these external helpers by default:
asciidoctor:--no-header-footer -rst2html:--leave-comments --initial-header-level=2pandoc:--mathjax
External helper Asciidoctor
The Asciidoctor community offers a wide set of tools for the AsciiDoc format that can be installed additionally to Hugo.
See the Asciidoctor docs for installation instructions. Make sure that also all
optional extensions like asciidoctor-diagram or asciidoctor-html5s are installed if required.
Some Asciidoctor parameters can be customized in Hugo:
| Parameter | Comment |
|---|---|
| backend | Don’t change this unless you know what you are doing. |
| doctype | Currently, the only document type supported in Hugo is article. |
| extensions | Possible extensions are asciidoctor-html5s, asciidoctor-bibtex, asciidoctor-diagram, asciidoctor-interdoc-reftext, asciidoctor-katex, asciidoctor-latex, asciidoctor-mathematical, asciidoctor-question. |
| attributes | Variables to be referenced in your AsciiDoc file. This is a list of variable name/value maps. See Asciidoctor’s attributes. |
| noHeaderOrFooter | Output an embeddable document, which excludes the header, the footer, and everything outside the body of the document. Don’t change this unless you know what you are doing. |
| safeMode | Safe mode level unsafe, safe, server or secure. Don’t change this unless you know what you are doing. |
| sectionNumbers | Auto-number section titles. |
| verbose | Verbosely print processing information and configuration file checks to stderr. |
| trace | Include backtrace information on errors. |
| failureLevel | The minimum logging level that triggers a non-zero exit code (failure). |
Hugo provides additional settings that don’t map directly to Asciidoctor’s CLI options:
- workingFolderCurrent
- Sets the working directory to be the same as that of the AsciiDoc file being processed, so that include will work with relative paths. This setting uses the
asciidoctorcli parameter--base-dirand attributeoutdir=. For rendering diagrams with asciidoctor-diagram,workingFolderCurrentmust be set totrue. - preserveTOC
- By default, Hugo removes the table of contents generated by Asciidoctor and provides it through the built-in variable
.TableOfContentsto enable further customization and better integration with the various Hugo themes. This option can be set totrueto preserve Asciidoctor’s TOC in the generated page.
Below are all the AsciiDoc related settings in Hugo with their default values:
markup:
asciidocExt:
attributes: {}
backend: html5
extensions: []
failureLevel: fatal
noHeaderOrFooter: true
preserveTOC: false
safeMode: unsafe
sectionNumbers: false
trace: false
verbose: false
workingFolderCurrent: false
[markup]
[markup.asciidocExt]
backend = 'html5'
extensions = []
failureLevel = 'fatal'
noHeaderOrFooter = true
preserveTOC = false
safeMode = 'unsafe'
sectionNumbers = false
trace = false
verbose = false
workingFolderCurrent = false
[markup.asciidocExt.attributes]
{
"markup": {
"asciidocExt": {
"attributes": {},
"backend": "html5",
"extensions": [],
"failureLevel": "fatal",
"noHeaderOrFooter": true,
"preserveTOC": false,
"safeMode": "unsafe",
"sectionNumbers": false,
"trace": false,
"verbose": false,
"workingFolderCurrent": false
}
}
}
Notice that for security concerns only extensions that do not have path separators (either \, / or .) are allowed. That means that extensions can only be invoked if they are in one’s ruby’s $LOAD_PATH (ie. most likely, the extension has been installed by the user). Any extension declared relative to the website’s path will not be accepted.
Example of how to set extensions and attributes:
[markup.asciidocExt]
extensions = ["asciidoctor-html5s", "asciidoctor-diagram"]
workingFolderCurrent = true
[markup.asciidocExt.attributes]
my-base-url = "https://example.com/"
my-attribute-name = "my value"
In a complex Asciidoctor environment it is sometimes helpful to debug the exact call to your external helper with all
parameters. Run Hugo with -v. You will get an output like
INFO 2019/12/22 09:08:48 Rendering book-as-pdf.adoc with C:\Ruby26-x64\bin\asciidoctor.bat using asciidoc args [--no-header-footer -r asciidoctor-html5s -b html5s -r asciidoctor-diagram --base-dir D:\prototypes\hugo_asciidoc_ddd\docs -a outdir=D:\prototypes\hugo_asciidoc_ddd\build -] ...
Learn markdown
Markdown syntax is simple enough to learn in a single sitting. The following are excellent resources to get you up and running: