Handlers

For every http status code there is a handler function defined in liberator. All have sensible defaults and will return a simple english error message or an empty response, whatever is appropriate.

Exception Handler since 0.12.0

If an exception is thrown by a decision or action function, it will be caught and the handler handle-exception is called.

List of all handler

Handler key	status code	redirect?
handle-ok	200
handle-created	201
handle-options	201
handle-accepted	202
handle-no-content	204
handle-moved-permanently	301	yes
handle-see-other	303	yes
handle-not-modified	304
handle-moved-temporarily	307	yes
handle-multiple-representations	310
handle-malformed	400
handle-unauthorized	401
handle-forbidden	403
handle-not-found	404
handle-method-not-allowed	405
handle-not-acceptable	406
handle-conflict	409
handle-gone	410
handle-precondition-failed	412
handle-request-entity-too-large	413
handle-uri-too-long	414
handle-unsupported-media-type	415
handle-unprocessable-entity since 0.9.0	422
handle-exception since 0.12.0	500
handle-not-implemented	501
handle-unknown-method	501
handle-service-not-available	503

Redirecting

The handlers that are marked as redirecting will set a “Location” header that is generated from the following mechanism:

Lookup in context since 0.9.0

Liberator uses the lookup key :location in the context. You can set this key from a decision function that decides on the redirection, e.g. :post-redirect?. The value can either be a constant value or a function that will be called with the current context.

Example:

(defresource postbox
  :allowed-methods [:post]
  :post-redirect? (fn [ctx] {:location "http://example.com/look-here/"}))

You could also use a constant value for :post-redirect like the execution model for liberator describes.

Lookup in resource

If no location was found in the context, then Liberator will lookup the key :location in the resource definition. Note that this value is used for all redirecting handlers if :location was not set the context.

Example:

(defresource postbox
  :allowed-methods [:post]
  :post-redirect? true 
  :location (fn [ctx] "http://example.com/look-here/"))