widdershins

OpenAPI / Swagger / AsyncAPI / Semoasa definition to Slate / Shins compatible markdown

Widdershins adverb:

• In a direction contrary to the sun's course;
• anticlockwise;
• helping you produce static documentation from your OpenAPI 3.0 / Swagger 2.0 / AsyncAPI 1.x / Semoasa 0.1.0 definition

News

• As of v3.0.0 Widdershins no longer expands the definition of OpenAPI body parameters / requestBodies by default, unless they have an inline schema. You can restore the old behaviour by using the --expandBody option.
• You may limit the depth of schema examples using the --maxDepth option. The default is 10.
• To omit schemas entirely, please copy and customise the main.dot template.
• As of v3.1.0 Widdershins includes a generated Authorization header in OpenAPI code samples. If you wish to omit this, see here.
• If you are using Node.js 6 or lower, please specify the --harmony flag.

To install

• Clone the git repository, or
• npm install [-g] widdershins

Examples

Command-line use looks like this:

node widdershins [options] {input-file|url} [[-o] output markdown]

For example:

node widdershins --search false --language_tabs 'ruby:Ruby' 'python:Python' --summary defs/petstore3.json -o petstore3.md

Options

CLI parameter name	JavaScript parameter name	Type	Default value	Description
--customApiKeyValue	options.customApiKeyValue	string	ApiKey	Set a custom API key value
--expandBody	options.expandBody	boolean	false	Expand the requestBody parameter to show all properties in the request body
--headings	options.headings	integer	2	The number of headings to show in the table of contents. Currently supported only by Shins, not by Slate, which lacks this feature.
--omitBody	options.omitBody	boolean	false	Omit the top-level fake body parameter object
--resolve	options.resolve	boolean	false	Resolve external $refs, using the source parameter or the input file as the base location
--shallowSchemas	options.shallowSchemas	boolean	false	Don't expand schemas past $refs
N/A	options.source	string		The absolute location or URL of the source file to use as the base to resolve relative references ($refs) from; required if options.resolve is set to true. For CLI commands, Widdershins uses the input file as the base for the $refs.
--summary	options.tocSummary	boolean	false	Use the operation summary as the TOC entry instead of the ID
--verbose	options.verbose	boolean	false	Increase verbosity
-h, --help	options.help	boolean	false	Show help
--version	options.version	boolean	false	Show version number
-c, --code	options.codeSamples	boolean	false	Turn generic code samples off
--httpsnippet	options.httpsnippet	boolean	false	Use httpsnippet to generate code samples
-d, --discovery	options.discovery	boolean	false	Include schema.org WebAPI discovery data
-e, --environment	options.environment	string	None	Load config/override options from file
-i, --includes	options.includes	string	None	List of files to include, comma separated
-l, --lang	options.lang	boolean	false	Automatically generate list of languages for code samples
--language_tabs	options.language_tabs	string	(Differs for each input type)	List of language tabs for code samples using language[:label[:client]] format
-m, --maxDepth	options.maxDepth	integer	10	Maximum depth for schema examples
-o, --outfile	options.outfile	string	(If left blank, output to stdout)	File to write output markdown to
-r, --raw	options.raw	boolean	false	Output raw schemas not example values
-s, --search	options.search	boolean	true	Whether to enable search or not
-t, --theme	options.theme	string	darkula	Syntax-highlighter theme to use
-u, --user_templates	options.user_templates	string	None	Directory to load override templates from
-x, --experimental	options.experimental	boolean		For backwards compatibility only, ignored
-y, --yaml	options.yaml	boolean	false	Display JSON schemas in YAML format
	options.templateCallback	function	None	A function that is called before and after each template (JavaScript code only)

In Node.JS code, create an options object and pass it to the Widdershins convert function, as in this example:

const converter = require('widdershins');
let options = {}; // defaults shown
options.codeSamples = true;
options.httpsnippet = false;
//options.language_tabs = [];
//options.language_clients = [];
//options.loadedFrom = sourceUrl; // only needed if input document is relative
//options.user_templates = './user_templates';
options.templateCallback = function(templateName,stage,data) { return data };
options.theme = 'darkula';
options.search = true;
options.sample = true; // set false by --raw
options.discovery = false;
options.includes = [];
options.shallowSchemas = false;
options.tocSummary = false;
options.headings = 2;
options.yaml = false;
//options.resolve = false;
//options.source = sourceUrl; // if resolve is true, must be set to full path or URL of the input document
converter.convert(apiObj,options,function(err,str){
  // str contains the converted markdown
});

To only include a subset of the pre-defined language-tabs, or to rename their display-names, you can override the options.language_tabs:

options.language_tabs = [{ 'go': 'Go' }, { 'http': 'HTTP' }, { 'javascript': 'JavaScript' }, { 'javascript--nodejs': 'Node.JS' }, { 'python': 'Python' }, { 'ruby': 'Ruby' }];

The --environment option specifies a JSON or YAML-formatted options object, for example:

{
  "language_tabs": [{ "go": "Go" }, { "http": "HTTP" }, { "javascript": "JavaScript" }, { "javascript--nodejs": "Node.JS" }, { "python": "Python" }, { "ruby": "Ruby" }],
  "verbose": true,
  "tagGroups": [
    {
      "title": "Companies",
      "tags": ["companies"]
    },
    {
      "title": "Billing",
      "tags": ["invoice-create", "invoice-close", "invoice-delete"]
    }
  ]
}

You can also use the environment file to group OAS/Swagger tagged paths together to create a more elegant table of contents, and overall page structure.

If you need to support a version of Slate <v1.5.0 (or a renderer which also doesn't support display-names for language-tabs, such as node-slate, slate-node or whiteboard), you can use the --environment option with the included whiteboard_env.json file to simply achieve this.

If you are using the httpsnippet option to generate code samples, you can specify the client library used to perform the requests for each language by overriding the options.language_clients:

options.language_clients = [{ 'shell': 'curl' }, { 'node': 'request' }, { 'java': 'unirest' }];

To see the list of languages and clients supported by httpsnippet, click here.

The loadedFrom option is only needed where the OpenAPI / Swagger definition does not specify a host, and (as per the OpenAPI specification) the API endpoint is deemed to be based on the source URL the definition was loaded from.

Note that the list of included files is simply passed into the header of the markdown file, they are actually included by Slate or the alternative you use.

To see the list of highlight-js syntax highlighting themes, click here.

Schema.org WebAPI discovery data is included if the discovery option above is set true. See the W3C WebAPI Discovery Community Group for more information.

Language tabs

Widdershins supports the x-code-samples vendor-extension to completely customise your documentation. Alternatively, you can edit the default code-samples in the templates sub-directory, or override them using the user_templates option to specify a directory containing your templates.

Widdershins supports the use of multiple language tabs with the same language (i.e. plain Javascript and Node.Js). To use this support you must be using Slate (or one of its ports compatible with) version 1.5.0 or higher. Shins versions track Slate version numbers.

Template parameters

Templates are compiled with doT.js.

Templates have access to a data object with a range of properties based on the document context.

If you specify an options.templateCallback function, it will be called before and after each template, with three parameters, the template name, the stage, ('pre' or 'post') and the current data object. You can mutate the data object in any way you see fit, as long as you return it. Content in the data.append property will be appended to the current output stream.

• Swagger 2.0 / OpenAPI 3.0.x template parameters
• AsyncAPI 1.x template parameters
• Semoasa 0.1.0 template parameters

User templates

To override a .dot template, you need to copy over the child .def partials as well.

To override a .def partial, you need to copy over the parent .dot template as well. For OpenAPI 3 this will be main.dot except for parameters, responses and callbacks, which are children of the operation.dot template.

This means it is usually easiest to copy all .dot and .def files to your user templates directory. A visual diff tool which can run across two directories (such as Meld or WinMerge) may be useful in bringing in changes from Widdershins updates.

Tests

To run a test-suite:

node testRunner {path-to-APIs}

The test harness currently expects .yaml or .json files and has been tested against

• APIs.guru
• Mermade OpenAPI definitions collection

Comparison between this and other OpenAPI / Swagger to Slate tools

Blog posting by the author of Widdershins.

Acknowledgements

• @latgeek for the logo.
• @vfernandestoptal for the httpsnippet support.

Widdershins in the wild

Please feel free to add a link to your API documentation here.

• GOV.UK Content API v1.0.0
• GOV UK Digital Marketplace API v1.0.0
• Capital One API
• Cognite Data API
• SpeckleWorks API
• Bank by API
• Open EO API
• Split Payments API
• LeApp daemon API

Widdershins and Shins

If you need a wrapper around both Widdershins and Shins, why not consider the following third-party projects:

• api2html
• shinner