ckan-embed

This is a widget for embedding live data searches from CKAN data portals into external websites. Currently only dataset (package) search results are supported, but the module can easily support any calls through the ckan-js library.

For some background on this project, visit the Swiss OGD Handbook.

Usage notes

This script can be used with any CKAN portal. It exposes a ck module which has a datasets function. The first parameter is the DOM container into which the widget should be loaded, the second parameter a fully qualified URL to the target CKAN portal, and the third can be a free text search query (for example, “statistik”).

Project dependencies include jQuery, Underscore, ckan.

Installation

(1) Add the ckan-embed script into the page:

<script src="https://cdn.jsdelivr.net/gh/opendata-swiss/ckan-embed/dist/ckan-embed.bundle.js"></script>

This includes non-blocking versions of dependency scripts. It is a relatively large (> 500 KB download - see issue #14), so if you are loading the project dependencies listed above in your web page already, use the minified version ckan-embed.min.js (only 37 KB) instead.

(2) Place the container somewhere on the page:

<div id="example-1">
    Loading '<a href="https://opendata.swiss">statistik</a>' datasets ...
</div>

(3) Add the init code - this will work if your script is in the header:

...
<script>
CKANembed.datasets('#example-1', 'https://opendata.swiss/', 'statistik');
</script>

The widget will then render in the #example-1 container. Some styling possibilities, such as showing the logo of the portal, are explored in test/style.css.

We recommend placing the script in the foot of the page and running this command in an onload routine for better performance, e.g.:

$(document).ready(function() {
  CKANembed.datasets('#example-1', 'https://opendata.swiss/', 'statistik');
});

If you used previous versions of the script, mind the fact that we’ve changed the global from ck to CKANembed:

<script>
var ck = CKANembed; // backwards compatibility
ck.datasets('#example-1', 'https://opendata.swiss/', 'statistik');
</script>

Advanced options

The script may also be initialized with a configuration object, for example in this case to show three datasets tagged ‘hospitals’, without using JSONP* and instead proxying the requests through to the API at the /ckanproxy/ path:

CKANembed.datasets('#example-2', 'https://opendata.swiss/', {
    fq:       'tags:hospitals',
    rows:     3,
    lang:     'de',
    jsonp:    false,
    proxy:    '/ckanproxy/'
}

• fq: allows use of filter queries
• rows: limit the number of results shown
• sort: custom sorting order (see note below)
• lang: default language for result links
• jsonp: toggle the use of JSONP (see note below)
• proxy: relative or absolute path to API proxy
• template: an HTML template for the results (see example)

Usage notes

If you are running this script on the same server or using a backend proxy (supported in all web servers) to the CKAN API, it is recommended that you disable JSONP with the jsonp: false option. We have made it to be enabled by default since many CKAN servers can still only be reached through this method.

The default sorting order is name asc (alphabetical name ascending). Besides name, package_count and title are allowed. On multilingual CKAN servers add language suffix e.g. title_string_en. For specifying ascending or descending order append asc or desc.

For more usage examples see the examples folder.

Developer notes

For information on the JavaScript CKAN client see ckan.js, for details of API usage see docs.ckan.org for package_search.

A web server like NGINX can be used to proxy requests and avoid the use of JSONP.

Build Process

To build ckan-embed.js and view the test examples, you must have yarn installed.

1. Run yarn in the ckan-embed folder to install dependencies.
2. Run yarn run build (this will invoke browserify to bundle the source files, and then uglify-js to create the minified version).
3. Run yarn run deploy to do tests and update the distributables.
4. Start a local webserver (e.g., python3 -m http.server 8000) in the root folder and then point your web browser at the examples directory (e.g., http://localhost:8000/examples/).

Acknowledgments

Developed with support from the Swiss Federal Archives.

This project was initially based on vega-embed.