hugo/docs/content/extras/dynamiccontent.md

aliases	date	menu	next	prev	title	weight
/doc/dynamiccontent/	2015-02-14	main parent extras	/extras/highlighting	/extras/datafiles	Dynamic Content	91

Dynamic content with a static site generator? Yes it is possible!

In addition to the data files feature, we have also implemented the feature "Dynamic Content", which lets you load any JSON or CSV file from nearly any resource.

"Dynamic Content" currently consists of two functions, getJson and getCsv, which are available in all template files.

Implementation details

Calling the functions with an URL

In any HTML template or Markdown document call the functions like:

{{ $dataJ := getJson "url" }}
{{ $dataC := getCsv "separator" "url" }}

or if you use a prefix or postfix for the URL the functions accept variadic arguments:

{{ $dataJ := getJson "url prefix" "arg1" "arg2" "arg n" }}
{{ $dataC := getCsv  "separator" "url prefix" "arg1" "arg2" "arg n" }}

The separator for getCsv must be put on the first position and can be only one character long.

All passed arguments will be joined to the final URL, example:

{{ $urlPre := "https://api.github.com" }}
{{ $gistJ := getJson $urlPre "/users/GITHUB_USERNAME/gists" }}

will resolve internally to:

{{ $gistJ := getJson "https://api.github.com/users/GITHUB_USERNAME/gists" }}

Eventually you can range over the array. This example will output the first 5 Github gists for a user:

<ul>
	{{ $urlPre := "https://api.github.com" }}
	{{ $gistJ := getJson $urlPre "/users/GITHUB_USERNAME/gists" }}
	{{range first 5 $gistJ }}
		{{ if .public }}
			<li><a href="{{ .html_url }}" target="_blank">{{.description}}</a></li>
		{{ end }}
	{{end}}
</ul>

Example for CSV files

For getCsv the one character long separator must be placed on the first position followed by the URL.

<table>
  <thead>
    <tr>
	<th>Name</th>
	<th>Position</th>
	<th>Salary</th>
    </tr>
  </thead>
  <tbody>
  {{ $url := "http://a-big-corp.com/finance/employee-salaries.csv" }}
  {{ $sep := "," }}
  {{ range $i, $r := getCsv $sep $url }}
    <tr>
      <td>{{ index $r 0 }}</td>
      <td>{{ index $r 1 }}</td>
      <td>{{ index $r 2 }}</td>
    </tr>
  {{ end }}
  </tbody>
</table>

The expression {{index $r number}} must be used to output the nth-column from the current row.

Caching of URLs

Each downloaded URL will be cached in the default folder $TMPDIR/hugo_cache/. The variable $TMPDIR will be resolved to your system dependent temporary directory.

With the command line flag --cacheDir you can specify any folder on your system as a caching directory.

If you don't like caching at all, you can fully disable to read from the cache with the command line flag --ignoreCache. However Hugo will always write, on each build of the site, to the cache folder (silent backup).

Authentication when using REST URLs

Currently you can only use those authentication methods that can be put into an URL. OAuth or other authentication methods are not implemented.

Loading local files

To load local files with the two functions getJson and getCsv the source files must reside within Hugos working directory. The file extension does not matter but the content.

It applies the same output logic as in the topic: Calling the functions with an URL.

Live reload

There is no chance to trigger a LiveReload when the content of an URL changes. However when a local JSON/CSV file changes then a live reload will be triggered of course. Symlinks not supported.

URLs and Live reload: If you change any local file and the live reload got triggered Hugo will either read the URL content from the cache or, if you have disabled the cache, Hugo will re-download the content. This can create huge traffic and you may also reach API limits quickly.

As downloading of content takes a while, Hugo stops with processing your markdown files until the content has been downloaded.

Examples

• Photo gallery JSON powered: https://github.com/pcdummy/hugo-lightslider-example
• Github Starred Repositories in a posts with the related short code.
• more?

The Future

YAML and TOML

If the community demands the implementation of getYaml YAML or getToml TOML these functions will certainly follow.

getSql

The outlook to support more sources is of course implementing SQL support. The following description is an initial idea and may change.

Maybe adding a new CLI option:

--sqlSource=path/to/filename.ext

--sqlSource

The file must start with [mysql|postres|mssql|...]_[\w]+.ext

The part before the first underscore specifies the driver to use, which can be one from https://github.com/golang/go/wiki/SQLDrivers.

The file itself contains only the connection string and no other comments or characters.

How the connection string looks like depends heavily on the used driver. For MySQL:

hugo --sqlSource=path/to/mysql_credentials.txt

The file mysql_credentials.txt contains the connection string: username:password@protocol(address)/dbname?param=value and nothing more!

In your template you can process getSql the same way as with the getJson function:

{{ $rows := getSql "SELECT id,artist,genre,title FROM musicTable" }}
<ul>
	{{range first 5 $rows }}
		<li>#{{ .id }} {{.artist}}</a></li>
	{{end}}
</ul>

Queries with SELECT * FROM table are of course also possible but should not be used. Returned values will be converted to strings.

Abusing getSql with DML or DDL statements causes Hugo to hang up.