Source

rest-bind / rest-bind.svnwiki

Full commit
[[tags: egg]]

== rest-bind

[[toc:]]

=== Description

REST Procedure Call

Generates wrappers to REST-like HTTP APIs

=== Source Code

[[https://bitbucket.org/knodium/rest-bind]]

=== Author

[[/users/andyjpb|Andy Bennett]]

=== Requirements

None

=== API

==== define-method

<syntax>(define-method (procedure-name path-arg... #!key query-arg...) uri-or-request body-writer body-reader header-reader</syntax>

Generates scheme procedures that call the underlying HTTP API with the parameters given.

Creates a procedure {{procedure-name}} that calls the HTTP API specified in {{uri-or-request}}. Arguments specified in {{path-arg}} are appended, in the other they appear, to the end of the URI, separated by /. These areguments are mandatory. Arguments specified in {{query-arg}} are optional and, if present are placed in the query string. They are named as they appear in the definition. Their value is that as given when {{procedure-name}} is called.

If body-writer is specified then an extra argument is appended to the {{path-arg}}s and is also mandatory.

When the {{procedure-name}} is called, the arguments are put into the URL. If {{body-writer}} is specified then it it is called with the value of the last postitional argument ({{path-arg}}). {{body-writer}} should return something suitable for use as the {{writer}} argument of {{call-with-input-request}}.

When all the preparations have been made, the URL is then fetched via {{call-with-input-request}} from [[http-client]]. If {{body-writer}} is not specified then the GET method is implied. If {{body-writer}} is specified then the POST method is implied. If the HTTP API calls for another method then {{uri-or-request}} must be specified using {{make-request}} from [[intarweb]]. {{body-reader}} is passed as the {{reader}} argument to {{call-with-input-request}}. The result of {{body-reader}} is one of the results of the call to {{procedure-name}}.

{{procedure-name}} currently returns the result of call-with-input-request.

{{header-reader}} is optional and currently ignored. It is intended that this be a procedure that can extract any required headers from the response.

=== Examples

See [[https://bitbucket.org/knodium/dropbox/src/e7929501b4fe2fee4c5e821cfc925b22bb51825d/dropbox-lolevel.scm|dropbox-lolevel.scm]] file for more examples.

Here we bind to
    https://api.dropbox.com/1/metadata/<root>/<path>?file_limit=<>&...

The Dropbox API docs specify the response as JSON so we read it with
read-json from [[medea]]. The request uses the GET method and has no
body so we substitute #f for the writer procedure.

    (define-method (metadata root path #!key file_limit hash list include_deleted rev locale)
    "https://api.dropbox.com/1/metadata/"
    #f
    read-json)


=== License

  Copyright (C) 2012, Andy Bennett
  All rights reserved.
  
  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions are met:
  
  Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer.
  Redistributions in binary form must reproduce the above copyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.
  Neither the name of the author nor the names of its contributors may be
  used to endorse or promote products derived from this software without
  specific prior written permission.
  
  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  POSSIBILITY OF SUCH DAMAGE.

=== Version History
* 0.1, (2012/11/04) : Preliminary support for binding to HTTP REST APIs. We don't currently support the sending of request bodies or the reading of custom response headers.