[Docs] [txt|pdf|xml] [Tracker] [Email] [Diff1] [Diff2] [Nits]

Versions: 00 01 02 03 04 05 06

Activity Streams (http://activitystrea.ms)                      J. Snell
Internet-Draft                                                       IBM
Intended status: Standards Track                                M. Marum
Expires: November 14, 2014                                      SugarCRM
                                                            May 13, 2014


              JSON Activity Streams 2.0 - Action Handlers
                 draft-snell-activitystreams-actions-06

Abstract

   This specification defines Action Handlers for use with the Activity
   Streams 2.0 format.

Author's Note

   Note that this document is a work-in-progress draft specification
   that does not yet represent a "standard".  It is the intention of
   this specification to propose a few new ideas and openly solicit
   feedback on their definition and use.  While this document might
   eventually evolve into an RFC the ideas described herein have not yet
   been broadly implemented and have definitions that will evolve
   through successive iterations of this draft.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at http://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on November 14, 2014.

Copyright Notice

   Copyright (c) 2014 IETF Trust and the persons identified as the
   document authors.  All rights reserved.





Snell & Marum           Expires November 14, 2014               [Page 1]


Internet-Draft               ActivityStreams                    May 2014


   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Overview  . . . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Action Handlers . . . . . . . . . . . . . . . . . . . . . . .   3
     2.1.  Content Security Policy . . . . . . . . . . . . . . . . .   6
   3.  HTTP Action Handler . . . . . . . . . . . . . . . . . . . . .   8
   4.  View Action Handler . . . . . . . . . . . . . . . . . . . . .  11
   5.  Embed Action Handler  . . . . . . . . . . . . . . . . . . . .  14
   6.  Intent Action Handler . . . . . . . . . . . . . . . . . . . .  17
   7.  Using "service" and "application" objects as action handlers   17
   8.  HTML Form Objects . . . . . . . . . . . . . . . . . . . . . .  18
   9.  Typed Payload Objects . . . . . . . . . . . . . . . . . . . .  19
   10. URL Template Objects  . . . . . . . . . . . . . . . . . . . .  20
   11. Parameters Object . . . . . . . . . . . . . . . . . . . . . .  21
     11.1.  The Parameter Object . . . . . . . . . . . . . . . . . .  22
     11.2.  Using UrlTemplate and TypedPayload objects as parameter
            descriptions . . . . . . . . . . . . . . . . . . . . . .  26
   12. Authentication Object . . . . . . . . . . . . . . . . . . . .  27
   13. Styles Object . . . . . . . . . . . . . . . . . . . . . . . .  28
   14. Security Considerations . . . . . . . . . . . . . . . . . . .  30
   15. IANA Considerations . . . . . . . . . . . . . . . . . . . . .  30
   16. Normative References  . . . . . . . . . . . . . . . . . . . .  30
   Appendix A.  Using Action Handlers From Other Vocabularies  . . .  31
     A.1.  Schema.org Actions Proposal . . . . . . . . . . . . . . .  31
     A.2.  Google's "Actions in the Inbox" . . . . . . . . . . . . .  31
     A.3.  Mixing Vocabularies . . . . . . . . . . . . . . . . . . .  32
     A.4.  Example Drawing From Multiple Vocabularies  . . . . . . .  33
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  35

1.  Overview

   The Activity Streams 2.0 [I-D.snell-activitystreams] specification
   introduces the notion of "actions" that can be associated with
   objects.  Using the "actions" property described in Sections 3.6 and
   3.6.1 of the Activity Streams 2.0 document, the producer of an object
   can declare a specific set of verbs appropriate for the object and
   map each of those to one or more objects ("action handlers") or
   resources capable of "carrying out" the verb.  This document expands



Snell & Marum           Expires November 14, 2014               [Page 2]


Internet-Draft               ActivityStreams                    May 2014


   on that mechanism by defining and describing a core set of action
   handler object types.

2.  Action Handlers

   An action handler is an Activity Streams 2.0 object whose objectType
   and member properties instruct a consuming application how to carry
   out the verb the action handler has been associated with.  For
   instance, given the following example:

     {
       "objectType": "note",
       "displayName": "Title of the note",
       "content": "This is a simple note.",
       "actions": {
         "share": {
           "objectType": "ViewActionHandler",
           "url": "http://example.org/share",
           "target": "_blank"
         },
         "like": {
           "objectType": "EmbedActionHandler",
           "mediaType": "text/plain",
           "content": "Hello World"
         }
       }
     }

   The "note" object has two declared actions, "share" and "like".  Each
   of those is associated with one action handler object.  The "share"
   action has a action handler of type "ViewActionHandler", while the
   "like" action has an "EmbedActionHandler".

   As illustrated in the example, action handlers are represented as
   Activity Streams 2.0 objects.  All such objects share a common set of
   base member properties as defined in the following table:

   +----------+-----------------------------+--------------------------+
   | Property | Value                       | Description              |
   +----------+-----------------------------+--------------------------+
   | confirm  | Boolean                     | True if the consuming    |
   |          |                             | application ought to     |
   |          |                             | seek confirmation prior  |
   |          |                             | to using the action      |
   |          |                             | handler to carry out     |
   |          |                             | it's associated action.  |
   |          |                             | Defaults to False.       |
   | context  | JSON Object                 | Contextual information   |



Snell & Marum           Expires November 14, 2014               [Page 3]


Internet-Draft               ActivityStreams                    May 2014


   |          |                             | associated with the      |
   |          |                             | action handler,          |
   |          |                             | represented as a JSON    |
   |          |                             | Object without any       |
   |          |                             | particular structure.    |
   |          |                             | How the context is used  |
   |          |                             | is dependent entirely on |
   |          |                             | the action handler       |
   |          |                             | definition and on how a  |
   |          |                             | consuming application    |
   |          |                             | chooses to implement the |
   |          |                             | action handler.          |
   | expects  | Link Value                  | For action handlers with |
   |          | [I-D.snell-activitystreams] | a distinct input         |
   |          |                             | requirement (e.g.        |
   |          |                             | HttpActionHandler), the  |
   |          |                             | expects property         |
   |          |                             | provides a description   |
   |          |                             | of the expected input.   |
   |          |                             | The value is expressed   |
   |          |                             | as either a String       |
   |          |                             | containing a fully       |
   |          |                             | qualified IRI, an        |
   |          |                             | Activity Stream Object,  |
   |          |                             | or an Array of IRI's or  |
   |          |                             | Objects.  When multiple  |
   |          |                             | values are provided,     |
   |          |                             | they MUST be considered  |
   |          |                             | as mutually exclusive    |
   |          |                             | alternatives.            |
   | returns  | Link Value                  | For action handlers with |
   |          | [I-D.snell-activitystreams] | a distinct output, the   |
   |          |                             | returns property         |
   |          |                             | provides a description   |
   |          |                             | of the expected output.  |
   |          |                             | The value is expressed   |
   |          |                             | as either a String       |
   |          |                             | containing a fully       |
   |          |                             | qualified IRI, an        |
   |          |                             | Activity Stream Object,  |
   |          |                             | or an Array of IRI's or  |
   |          |                             | Objects. When multiple   |
   |          |                             | values are provided,     |
   |          |                             | they MUST be considered  |
   |          |                             | as mutually exclusive    |
   |          |                             | alternatives.            |
   | auth     | Authentication Value        | For action handlers with |
   |          | (Section 12)                | specific authentication  |



Snell & Marum           Expires November 14, 2014               [Page 4]


Internet-Draft               ActivityStreams                    May 2014


   |          |                             | requirements, the "auth" |
   |          |                             | property provides        |
   |          |                             | information about the    |
   |          |                             | specific authentication  |
   |          |                             | mechanisms supported.    |
   | requires | Link Value                  | An optional Link Value   |
   |          | [I-D.snell-activitystreams] | whose value(s) describe  |
   |          |                             | features or behaviors an |
   |          |                             | implementation MUST      |
   |          |                             | support in order to      |
   |          |                             | carry out the action.    |
   |          |                             | Requirements are         |
   |          |                             | designed to be           |
   |          |                             | intentionally open-ended |
   |          |                             | and will vary depending  |
   |          |                             | on specific Action       |
   |          |                             | Handler type. Any        |
   |          |                             | implementation that does |
   |          |                             | not support any          |
   |          |                             | specified required       |
   |          |                             | feature MUST ignore the  |
   |          |                             | Action Handler.          |
   | prefers  | Link Value                  | An optional Link Value   |
   |          | [I-D.snell-activitystreams] | whose value(s) describe  |
   |          |                             | features or behaviors an |
   |          |                             | implementation SHOULD    |
   |          |                             | support in order to      |
   |          |                             | carry out the action.    |
   |          |                             | Requirements are         |
   |          |                             | designed to be           |
   |          |                             | intentionally open-ended |
   |          |                             | and will vary depending  |
   |          |                             | on specific Action       |
   |          |                             | Handler type. Any        |
   |          |                             | implementation that does |
   |          |                             | not support any          |
   |          |                             | specified preferred      |
   |          |                             | feature MAY ignore the   |
   |          |                             | feature.                 |
   +----------+-----------------------------+--------------------------+

   This specification defines four specific base types of action
   handler:

   o  The HTTP Action Handler (Section 3),

   o  The View Action Handler (Section 4),




Snell & Marum           Expires November 14, 2014               [Page 5]


Internet-Draft               ActivityStreams                    May 2014


   o  The Embed Action Handler (Section 5), and

   o  The Intent Action Handler (Section 6).

   Implementations are free to use Activity Stream objects of any
   objectType as an action handler.  Consuming applications MAY ignore
   any object it encounters that use objectTypes that are not recognized
   or supported as action handlers.  Alternatively, the consuming
   application MAY treat such objects as implied Intent Action Handlers
   (Section 6).

   Multiple independent action handlers can be associated with any
   single verb using a JSON Array.  The ordering of objects within such
   an array is not considered to be significant.

   For example, in the following, the "share" action has two associated
   action handlers:

     {
       "objectType": "event",
       "displayName": "Party!",
       "content": "We're going to party like it's 1999!",
       "id": "urn:example:events:123",
       "actions": {
         "share": [
           {
             "objectType": "HttpActionHandler",
             "method": "POST",
             "url": "http://example.org/share-this/123",
             "returns": {
               "objectType": "TypedPayload",
               "mediaType": "text/html"
             }
           },
           {
             "objectType": "EmbedActionHandler",
             "mediaType": "text/html",
             "content": "<div>...</div>"
           }
         ]
       }
     }

2.1.  Content Security Policy

   Note that all Action Handler types are subject to any relevant active
   Content Security Policy [W3C.WD-CSP11-20140211], or CSP, that is in-
   scope for the context in which the Action Handler is being invoked.



Snell & Marum           Expires November 14, 2014               [Page 6]


Internet-Draft               ActivityStreams                    May 2014


   The specific CSP directive that applies to a particular action
   handler type may vary depending on the Action Handler's objectType.

   Because the successful application of the Content Security Policy
   depends on the ability to determine the Origin [RFC6454] with which
   content is associated, the following rules for determining the origin
   for an Action Handler apply:

      If the Action Handler contains a "url" property, and that property
      is being used to invoke the handler, the URL specified is used to
      establish the origin as defined in [RFC6454], Section 4.

      Otherwise, the Origin is derived from the Base URI of the Action
      Handler as determined by following the guidelines specified in
      Section 6.1 of the JSON-LD specification
      [W3C.REC-json-ld-20140116].

   For instance, the example below illustrates an HTTP response carrying
   an Activity Streams object with three separate Action Handlers, each
   with a distinct Origin:































Snell & Marum           Expires November 14, 2014               [Page 7]


Internet-Draft               ActivityStreams                    May 2014


   HTTP/1.1 200 OK
   Content-Type: application/activity+json
   Content-Location: http://example.net/baz

   {
     "objectType": "note",
     "content": "This is a simple note",
     "actions": {
       "view": {
         {
           "objectType": "ViewActionHandler",
           "url": "http://example.org/foo"
         },
         {
           "objectType": "EmbedActionHandler",
           "content": "<div>This is fun</div>",
           "@context": {
             "@base": "https://example.com:8443/bar"
           }
         },
         {
           "objectType": "IntentActionHandler",
           "context": {
             "a": "b",
             "b": "c"
           }
         }
       }
     }
   }

   The Origin for the "ViewActionHandler" is determined to be "http://
   example.org:80"; the Origin for the "EmbedActionHandler" is "http://
   example.com:8443"; and the Origin for the "IntentActionHandler" is
   "http://example.net".

3.  HTTP Action Handler

   An HTTP Action Handler describes an HTTP request/response flow used
   to carry out an action.  It is identified using an objectType value
   of "HttpActionHandler".

   The defining characteristic of the HttpActionHandler is that the the
   HTTP request and response flow occur independently of any browser or
   navigation context.  In other words, invocation of the handler MUST
   NOT directly cause the user agent to navigate to or visually display
   the results of the HTTP request.  This makes the HttpActionHandler
   suited primarily for RESTful API style operations in much the same



Snell & Marum           Expires November 14, 2014               [Page 8]


Internet-Draft               ActivityStreams                    May 2014


   way that a web application developer would use the XMLHttpRequest
   object.

   +----------+------------------------+-------------------------------+
   | Property | Value                  | Description                   |
   +----------+------------------------+-------------------------------+
   | url      | Link Value             | Specifies the HTTP or HTTPS   |
   |          |                        | URL to which the HTTP request |
   |          |                        | is directed.                  |
   | method   | HTTP Method String     | The HTTP method to use.       |
   |          | (e.g. "GET", "POST",   | Defaults to "GET"             |
   |          | "PUT", etc)            |                               |
   +----------+------------------------+-------------------------------+

   For example:

     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "share": {
           "objectType": "HttpActionHandler",
           "url": "http://example.org/foo",
           "method": "POST"
         }
       }
     }

   In the Activity Streams 2.0 format, the "url" property is defined as
   a "Link Value", this means that it is possible for the value of the
   "url" property to be an Activity Stream object that a consuming
   application can use to resolve the actual target URL.  This
   specification defines a new UrlTemplate (Section 10) objectType
   specifically intended for such use.

   The UrlTemplate object can be used within an HTTP Action Handler, for
   instance, whenever carrying out the HTTP request requires the
   construction of a new URL that includes variable parameters:












Snell & Marum           Expires November 14, 2014               [Page 9]


Internet-Draft               ActivityStreams                    May 2014


     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "review": {
           "objectType": "HttpActionHandler",
           "url": {
             "objectType": "UrlTemplate",
             "template": "http://example.org/note/123{?rating}",
             "parameters": {
               "rating": {
                 "displayName": "Rating",
                 "maxInclusive": 5,
                 "minInclusive": 1,
                 "type": "unsignedInt"
               }
             }
           },
           "method": "POST"
         }
       }
     }

   If the HTTP request requires an input payload, the HttpActionHandler
   object can contain an "expects" property.  The value of "expects" is
   an Activity Streams 2.0 "Link Value" represented either as a simple
   JSON string containing a fully qualified IRI, an Activity Stream
   object, or an array of IRI's or Objects.  This specification defines
   a new HtmlForm (Section 8) objectType to be used whenever the input
   of the HTTP request is an HTML Form POST.  A new TypedPayload
   (Section 9) objectType is defined for use whenever the input is an
   arbitrary MIME media type.

   For example, the following describes an HTML Form post with a single
   "foo" parameter submitted using the "application/x-www-form-
   urlencoded" format:














Snell & Marum           Expires November 14, 2014              [Page 10]


Internet-Draft               ActivityStreams                    May 2014


     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "share": {
           "objectType": "HttpActionHandler",
           "method": "POST",
           "url": "http://example.org/foo",
           "expects": {
             "objectType": "HtmlForm",
             "mediaType": "application/x-www-form-urlencoded",
             "parameters": {
               "foo": {
                 "type": "string",
                 "displayName": "Foo Property"
               }
             }
           }
         }
       }
     }

   When a Content Security Policy is in effect, invocation of the HTTP
   Action Handler is always governed by the "connect-src" directive
   defined in Section 3.2.5.3 of [W3C.WD-CSP11-20140211].  Further, when
   the HTTP Action Hander specifies any method other than "GET", and the
   input when invoking the action handler is an HTML Form, the handler
   is additionally governed by the CSP "form-action" directive
   (Section 3.2.5.6).

4.  View Action Handler

   The View Action Handler describes an action that causes either an
   existing or new browser context to be navigated to the identified
   resource.  It is specified using an objectType value of
   "ViewActionHandler".

   ViewActionHandler is roughly equivalent to the HTML anchor tag in
   that invocation of the handler causes the user agent to navigate to
   the identified resource.  Unlike the anchor tag, however, the
   ViewActionHandler can specify the HTTP method, input payload and
   expected output.








Snell & Marum           Expires November 14, 2014              [Page 11]


Internet-Draft               ActivityStreams                    May 2014


   +----------+---------------+----------------------------------------+
   | Property | Value         | Description                            |
   +----------+---------------+----------------------------------------+
   | url      | Link Value    | Specifies the HTTP or HTTPS URL to     |
   |          |               | which the HTTP request is directed.    |
   | method   | HTTP Method   | The HTTP method to use. Defaults to    |
   |          | String (e.g.  | "GET"                                  |
   |          | "GET",        |                                        |
   |          | "POST",       |                                        |
   |          | "PUT", etc)   |                                        |
   | target   | Browsing      | Specifies the Browsing Context Name or |
   |          | Context Name  | keyword, as defined by                 |
   |          | or Keyword    | [W3C.CR-html5-20140429], that will be  |
   |          |               | used when the action handler is        |
   |          |               | invoked.                               |
   | sandbox  | HTML5         | An optional string specifying HTML5    |
   |          | "sandbox"     | [W3C.CR-html5-20140429] sandbox        |
   |          | restrictions  | restrictions that ought to be applied  |
   |          |               | to the content referenced by the "url" |
   |          |               | property.                              |
   +----------+---------------+----------------------------------------+

     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "view": {
           "objectType": "ViewActionHandler",
           "url": "http://example.org/foo",
           "target": "_new"
         }
       }
     }

   As a shortcut, ViewActionHandlers that use the "GET" method can be
   specified using a JSON string containing the absolute URL.  For
   instance:

     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "view": "http://example.org/foo"
       }
     }




Snell & Marum           Expires November 14, 2014              [Page 12]


Internet-Draft               ActivityStreams                    May 2014


   In such cases, the "target" property is assumed to be unspecified.

   If the intended HTTP request uses the GET method, and the target URL
   is to be constructed by expanding a URL Template, the UrlTemplate
   object itself can be used directly as the action handler.

   In other words, the following example:

     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "view": {
           "objectType": "ViewActionHandler",
           "method": "GET",
           "url": {
             "objectType": "UrlTemplate",
             "template": "http://example.org/note/{noteid}",
             "parameters": {
               "noteid": {
                 "type": "nonNegativeInteger",
                 "totalDigits": 5
               }
             }
           }
         }
       }
     }

   Can, instead, be specified as:




















Snell & Marum           Expires November 14, 2014              [Page 13]


Internet-Draft               ActivityStreams                    May 2014


     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "view": {
           "objectType": "UrlTemplate",
           "template": "http://example.org/note/{noteid}",
           "parameters": {
             "noteid": {
               "type": "nonNegativeInteger",
               "totalDigits": 5
             }
           }
         }
       }
     }

   When a Content Security Policy is in effect, View Action Handlers are
   subject to the same processing requirements as HTML anchor and form
   elements.  For instance, the "child_src" directive governs whether or
   not the View Action Handler is permitted to create nested or
   auxiliary browsing contexts, while the "form_action" directive
   governs a View Action Handler that uses any method other than "GET"
   and whose input is an HTML Form.

5.  Embed Action Handler

   An Embed Action Handler defines static or dynamic content to be
   visually rendered to carry out an action.  Examples of embeds can
   include static HTML, images, videos, gadgets and applications.  It is
   identified using an objectType value of "EmbedActionHandler".

   The defining characteristic that differentiates an Embed Action
   Handler from a View Action Handler is that the former always implies
   the use of the current browsing context and that content is expected
   to be displayed inline as embedded content (similar to the way HTML5
   img, audio, video and iframe tags are handled).













Snell & Marum           Expires November 14, 2014              [Page 14]


Internet-Draft               ActivityStreams                    May 2014


   +-----------+--------------+----------------------------------------+
   | Property  | Value        | Description                            |
   +-----------+--------------+----------------------------------------+
   | url       | Link Value   | The URL from which to retrieve the     |
   |           |              | content for this embed.                |
   | content   | String       | The character based "static" content   |
   |           |              | to be embeded. The "mediaType"         |
   |           |              | parameter specifies the MIME media     |
   |           |              | type of the content.                   |
   | mediaType | MIME Media   | The MIME Media Type of the embedded    |
   |           | Type         | content.                               |
   | style     | Styles       | Visual CSS styling hints to apply to   |
   |           | Object       | the element containing the embedded    |
   |           | (Section 13) | content.                               |
   | preview   | Link Value   | A reference to a "preview"             |
   |           |              | representation of the embedded         |
   |           |              | content. Typically, this would a URL   |
   |           |              | to a thumbnail or screenshot image of  |
   |           |              | the content.                           |
   | sandbox   | HTML5        | An optional string specifying HTML5    |
   |           | "sandbox"    | [W3C.CR-html5-20140429] sandbox        |
   |           | restrictions | restrictions that ought to be applied  |
   |           |              | to the content referenced by the "url" |
   |           |              | property.                              |
   +-----------+--------------+----------------------------------------+

   In the following example, the "view" action is associated with an
   "EmbedActionHandler" containing a static fragment of HTML markup:

     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "view": {
           "objectType": "EmbedActionHandler",
           "content": "<div>This is some bit of embedded HTML</div>",
           "mediaType": "text/html",
           "style": {
             "height": "100px",
             "width": "100px",
             "box-shadow": "10px 10px 5px #888888"
           },
           "displayName": "Some embedded content",
           "preview": "http://example.org/preview/123.jpg"
         }
       }
     }



Snell & Marum           Expires November 14, 2014              [Page 15]


Internet-Draft               ActivityStreams                    May 2014


   Alternatively, the embedded content can be referenced by URL:

     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "view": {
           "objectType": "EmbedActionHandler",
           "url": "http://example.org/foo",
           "mediaType": "text/html"
         }
       }
     }

   The mediaType parameter specifies the type of content to be embedded.
   Consuming applications MAY ignore Embed Action Handlers that specify
   unrecognized or unsupported mediaTypes.

   Example:

     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "view": {
           "objectType": "EmbedActionHandler",
           "url": "http://example.org/foo.mpg",
           "mediaType": "video/mpeg"
         }
       }
     }

   Exactly how the content referenced by the Action Handler is embedded
   and displayed is dependent on the implementation and may vary by
   content type.  For instance, an implementation invoking an Embed
   Action Handler that references an image resource (e.g. "image/png")
   might use the HTML5 img tag to embed the content.

   When a Content Security Policy is in effect, the specific directives
   that apply will be entirely dependent on the type of content being
   embedded and how the implementation chooses to embed it.  For
   instance, embedded image resources will be governed by the
   "image_src" directive while embedded video will be governed by the
   "media_src" directive.  Please refer to the Content Security Policy
   [W3C.WD-CSP11-20140211] specification for a detailed explanation of
   each of the directives that may apply.



Snell & Marum           Expires November 14, 2014              [Page 16]


Internet-Draft               ActivityStreams                    May 2014


6.  Intent Action Handler

   An Intent Action Handler provides a generic way for the publisher of
   an Activity object to tell the consuming application to figure out
   how to handle the action on it's own.  The consumer can, for
   instance, pass the object off to some other native platform
   application.  It is identified using an objectType value of
   "IntentActionHandler".

   For example:

     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "share": {
           "objectType": "IntentActionHandler",
           "displayName": "Share This",
           "context": {
             "foo": "ABC",
             "bar": 123
           }
         }
       }
     }

   Whether and how the Intent Action Handler is invoked is dependent
   entirely on the implementation.  Regardless of how the handler is
   invoked, the implementation MUST, at a minimum, pass the value of the
   "context" property along.

7.  Using "service" and "application" objects as action handlers

   The "service" and "application" object are existing objectTypes
   defined by the Activity Streams 1.0 core schema.  While these objects
   were not originally designed to be used as action handlers, they can
   be.  Specifically, the "service" objectType can be used when the
   action is to be carried out using some specific third party service
   interface; the "application" objectType can be used when the action
   is to be carried out by deferring some some specific native platform
   application.  When such objectTypes are used as actions handlers,
   they are to be treated as specializations of Intent Action Handler.

   For example:






Snell & Marum           Expires November 14, 2014              [Page 17]


Internet-Draft               ActivityStreams                    May 2014


     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "share": {
           "objectType": "service",
           "displayName": "My Sharing Service",
           "url": "http://share.example.org/api"
         },
         "save": {
           "objectType": "application",
           "displayName": "Read this later!",
           "platform": "android",
           "id": "123",
           "url": "http://play.google.com/..."
         }
       }
     }

8.  HTML Form Objects

   +------------+----------------+-------------------------------------+
   | Property   | Value          | Description                         |
   +------------+----------------+-------------------------------------+
   | mediaType  | MIME Media     | Defaults to "application/x-www-     |
   |            | Type           | form-urlencoded"                    |
   | parameters | Parameters     | Defines the HTML form parameters.   |
   |            | Object         |                                     |
   |            | (Section 11)   |                                     |
   +------------+----------------+-------------------------------------+




















Snell & Marum           Expires November 14, 2014              [Page 18]


Internet-Draft               ActivityStreams                    May 2014


   For example:

     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "review": {
           "objectType": "ViewActionHandler",
           "method": "POST",
           "target": "_new",
           "url": "http://example.org/foo",
           "expects": {
             "objectType": "HtmlForm",
             "mediaType": "application/x-www-form-urlencoded",
             "parameters": {
               "foo": {
                 "displayName": "Foo",
                 "type": "string",
                 "placeholder": "Foo"
               },
               "bar": {
                 "type": "string",
                 "value": "Provided Value"
               }
             }
           }
         }
       }
     }

   Is roughly equivalent to the following HTML form:

     <form method="post" action="http://example.org/foo" target="_new">
       <label for="foo">Foo:</label>
       <input id="foo" name="foo" type="input" placeholder="Foo" />
       <input name="bar" type="hidden" value="Provided Value" />
       <input type="submit" />
     </form>

9.  Typed Payload Objects










Snell & Marum           Expires November 14, 2014              [Page 19]


Internet-Draft               ActivityStreams                    May 2014


   +-----------+-----------------------------+-------------------------+
   | Property  | Value                       | Description             |
   +-----------+-----------------------------+-------------------------+
   | mediaType | MIME Media Type             | The MIME Media Type of  |
   |           |                             | the Payload             |
   | type      | Type Value                  | An optional Type Value  |
   |           | [I-D.snell-activitystreams] | that describes the      |
   |           |                             | payloads semantic type. |
   | schema    | Link Value                  | An optional Link Value  |
   |           | [I-D.snell-activitystreams] | whose value(s) describe |
   |           |                             | the structure of the    |
   |           |                             | payload data. The value |
   |           |                             | is represented either   |
   |           |                             | as a String with a      |
   |           |                             | fully qualified IRI, an |
   |           |                             | Activity Stream object, |
   |           |                             | or an Array of IRIs and |
   |           |                             | Objects. If multiple    |
   |           |                             | values are provided,    |
   |           |                             | they are to be          |
   |           |                             | considered mutually     |
   |           |                             | exclusive alternatives. |
   +-----------+-----------------------------+-------------------------+

   For example:

     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "review": {
           "objectType": "HttpActionHandler",
           "method": "POST",
           "url": "http://example.org/foo",
           "expects": {
             "objectType": "TypedPayload",
             "mediaType": "text/json",
           }
         }
       }
     }

10.  URL Template Objects

   Objects with the "UrlTemplate" object type represent [RFC6570] URL
   Templates.




Snell & Marum           Expires November 14, 2014              [Page 20]


Internet-Draft               ActivityStreams                    May 2014


   +------------+-------------------------+----------------------------+
   | Property   | Value                   | Description                |
   +------------+-------------------------+----------------------------+
   | template   | URL Template            | The [RFC6570] URL Template |
   | parameters | Parameters Object       | Defines the URL Template   |
   |            | (Section 11)            | parameters                 |
   +------------+-------------------------+----------------------------+

   {
     "objectType": "note",
     "displayName": "A simple note object",
     "content": "This is a simple note.",
     "actions": {
       "review": {
         "objectType": "UrlTemplate",
         "template": "http://example.org/notes/{noteid}",
         "parameters": {
           "noteid": {
             "type": "nonNegativeInteger",
             "totalDigits": 5
           }
         }
       }
     }
   }

   If the given URL template includes any parameter tokens that do not
   appear within the "parameters" property, the parameter value type is
   assumed to be a UTF-8 encoded xsd:string with no maximum length.

11.  Parameters Object

   A Parameters Object is used to provide descriptions of the variable
   inputs of objects such as HTML Forms (Section 8) and URL Templates
   (Section 10).  The object is expressed as a JSON dictionary mapping
   parameter names to parameter descriptions which take the form of
   either an XML Schema type name [W3C.REC-xmlschema-2-20041028], an
   absolute IRI, a parameter object (Section 11.1), or in some limited
   cases, TypedPayload or UrlTemplate objects.

   By default, all parameters are assumed to be required.  When a
   parameter is described using an object, the object MAY contain a
   boolean "required" member.  If "required" is false, use of the
   parameter is assumed to be optional.







Snell & Marum           Expires November 14, 2014              [Page 21]


Internet-Draft               ActivityStreams                    May 2014


   Using the Parameters Object in UrlTemplate objects:

     {
       "objectType": "UrlTemplate",
       "template": "http://example.org{/foo,bar}"
       "parameters": {
         "foo": "string",
         "bar": {
           "type": "string",
           "required": false
         }
       }
     }

   In this example, both the "foo" and "bar" parameters conform to the
   XML Schema type "xsd:string".  The "foo" parameter is required while
   the "bar" parameter is optional.

   Using the Parameters Object in HtmlForm objects:

     {
       "objectType": "HtmlForm",
       "mediaType": "application/x-www-form-urlencoded",
       "parameters": {
         "foo": {
           "displayName": "Foo",
           "type": "string"
         },
         "bar": {
           "displayName": "Bar",
           "type": "string",
           "required": false
         }
       }
     }

11.1.  The Parameter Object

   Parameter objects provide a rich description of a single parameter in
   a manner that is aligned with the commonly used XML Schema type
   system [W3C.REC-xmlschema-2-20041028].

   +-------------+--------------------------+--------------------------+
   | Property    | Value                    | Description              |
   +-------------+--------------------------+--------------------------+
   | displayName | Natural Language Value [ | An Activity Streams 2.0  |
   |             | I-D.snell-activitystream | Natural Language Value.  |
   |             | s]                       |                          |



Snell & Marum           Expires November 14, 2014              [Page 22]


Internet-Draft               ActivityStreams                    May 2014


   | required    | boolean                  | True if the parameter is |
   |             |                          | required. Defaults to    |
   |             |                          | true.                    |
   | repeated    | boolean                  | True if the parameter    |
   |             |                          | can be repeated zero or  |
   |             |                          | more times. Defaults to  |
   |             |                          | false.                   |
   | value       | (Any)                    | Provides a fixed value   |
   |             |                          | for the parameter. When  |
   |             |                          | specified,               |
   |             |                          | implementations MUST use |
   |             |                          | the specified value.     |
   | default     | (Any)                    | Provides a default value |
   |             |                          | for the parameter. When  |
   |             |                          | specified,               |
   |             |                          | implementations MUST use |
   |             |                          | the specified value if   |
   |             |                          | no other value is not    |
   |             |                          | supplied.                |
   | type        | XSD [W3C.REC-xmlschema-2 | Identifies the value     |
   |             | -20041028] type name or  | type using either an XML |
   |             | IRI                      | Schema [W3C.REC-xmlschem |
   |             |                          | a-2-20041028] simple     |
   |             |                          | type name or an absolute |
   |             |                          | IRI. If an               |
   |             |                          | implementation           |
   |             |                          | encounters a type it     |
   |             |                          | does not recognize, the  |
   |             |                          | property MAY be ignored. |
   |             |                          | When not specified, the  |
   |             |                          | value type is assumed to |
   |             |                          | be a UTF-8 encoded       |
   |             |                          | "xsd:string".            |
   | enumeration | Array of (Any)           | Provides a fixed array   |
   |             |                          | of possible values for   |
   |             |                          | the parameter.  When     |
   |             |                          | specified,               |
   |             |                          | implementations MUST use |
   |             |                          | one of the specified     |
   |             |                          | values.                  |
   | minLength   | Non-Negative Integer     | Specifies the minimum    |
   |             |                          | "unit of length" for the |
   |             |                          | value. The "unit of      |
   |             |                          | length" depends entirely |
   |             |                          | on the value type as     |
   |             |                          | specified by the "type"  |
   |             |                          | property. For instance,  |
   |             |                          | For xsd:string, the      |



Snell & Marum           Expires November 14, 2014              [Page 23]


Internet-Draft               ActivityStreams                    May 2014


   |             |                          | length is determined by  |
   |             |                          | the number of            |
   |             |                          | characters; for          |
   |             |                          | xsd:hexBinary, the       |
   |             |                          | length is determined by  |
   |             |                          | the number of encoded    |
   |             |                          | 8-bit octets.            |
   | maxLength   | Non-Negative Integer     | Specifies the maximum    |
   |             |                          | "unit of length" for the |
   |             |                          | value. The "unit of      |
   |             |                          | length" depends entirely |
   |             |                          | on the value type as     |
   |             |                          | specified by the "type"  |
   |             |                          | property. For instance,  |
   |             |                          | For xsd:string, the      |
   |             |                          | length is determined by  |
   |             |                          | the number of            |
   |             |                          | characters; for          |
   |             |                          | xsd:hexBinary, the       |
   |             |                          | length is determined by  |
   |             |                          | the number of encoded    |
   |             |                          | 8-bit octets.            |
   | maxInclusiv | (Any)                    | A value that is          |
   | e           |                          | considered to be the     |
   |             |                          | inclusive upper bound of |
   |             |                          | a range of possible      |
   |             |                          | values. This would       |
   |             |                          | typically be used only   |
   |             |                          | with numeric parameters. |
   | maxExclusiv | (Any)                    | A value that is          |
   | e           |                          | considered to be the     |
   |             |                          | exclusive upper bound of |
   |             |                          | a range of possible      |
   |             |                          | values. This would       |
   |             |                          | typically be used only   |
   |             |                          | with numeric parameters. |
   | minInclusiv | (Any)                    | A value that is          |
   | e           |                          | considered to be the     |
   |             |                          | inclusive lower bound of |
   |             |                          | a range of possible      |
   |             |                          | values. This would       |
   |             |                          | typically be used only   |
   |             |                          | with numeric parameters. |
   | minExclusiv | (Any)                    | A value that is          |
   | e           |                          | considered to be the     |
   |             |                          | exclusive lower bound of |
   |             |                          | a range of possible      |
   |             |                          | values. This would       |



Snell & Marum           Expires November 14, 2014              [Page 24]


Internet-Draft               ActivityStreams                    May 2014


   |             |                          | typically be used only   |
   |             |                          | with numeric parameters. |
   | step        | Non-negative Number      | Specifies the legal      |
   |             |                          | numeric interval between |
   |             |                          | acceptable values for    |
   |             |                          | the parameter. The step  |
   |             |                          | value MUST be a number   |
   |             |                          | and MUST conform to the  |
   |             |                          | specified type. For      |
   |             |                          | instance, if type is     |
   |             |                          | "unsignedInt", then      |
   |             |                          | step=2 would indicate    |
   |             |                          | legal values of 0, 2, 4, |
   |             |                          | 6, and so on. The step   |
   |             |                          | property MAY be ignored  |
   |             |                          | if it's value does not   |
   |             |                          | correspond to the        |
   |             |                          | expected type.           |
   | totalDigits | Non-negative integer     | Specifies the maximum    |
   |             |                          | number of digits         |
   |             |                          | (integer and fractional) |
   |             |                          | that can be included in  |
   |             |                          | numeric values. The      |
   |             |                          | totalDigits property     |
   |             |                          | MUST be ignored if the   |
   |             |                          | value type identified by |
   |             |                          | the type property is not |
   |             |                          | a numeric type.          |
   | fractionDig | Non-negative integer     | Specifies the maximum    |
   | its         |                          | number of fractional     |
   |             |                          | digits that can be       |
   |             |                          | included in numeric      |
   |             |                          | values. The              |
   |             |                          | fractionDigits property  |
   |             |                          | MUST be ignored if the   |
   |             |                          | value type identified by |
   |             |                          | the type property is not |
   |             |                          | a numeric type.          |
   | pattern     | String or Array of       | One or more Regular      |
   |             | Strings                  | Expressions that         |
   |             |                          | describe the acceptable  |
   |             |                          | structure of the value.  |
   |             |                          | Typically used when the  |
   |             |                          | value is a string.       |
   |             |                          | Multiple patterns are    |
   |             |                          | mutually exclusive       |
   |             |                          | options. That is, the    |
   |             |                          | parameter value is       |



Snell & Marum           Expires November 14, 2014              [Page 25]


Internet-Draft               ActivityStreams                    May 2014


   |             |                          | expected to conform to   |
   |             |                          | at least one of the      |
   |             |                          | given patterns.          |
   | placeholder | Natural Language Value [ | An optional Natural      |
   |             | I-D.snell-activitystream | Language Value providing |
   |             | s]                       | a text hint that         |
   |             |                          | describes the expected   |
   |             |                          | value of the parameter.  |
   +-------------+--------------------------+--------------------------+

   Using the Parameter Object in HtmlForm objects:

     {
       "objectType": "HtmlForm",
       "mediaType": "application/x-www-form-urlencoded",
       "parameters": {
         "foo": "string",
         "bar": {
           "displayName": "Bar",
           "required": false,
           "repeated": false,
           "type": "unsignedInt",
           "default": 3,
           "minInclusive": 1,
           "maxInclusive": 5
         }
       }
     }

11.2.  Using UrlTemplate and TypedPayload objects as parameter
       descriptions

   In certain cases, when the value of a parameter is expected to be
   either a URI or IRI, the UrlTemplate objectType (Section 10) MAY be
   used as the parameter description.  In such cases, the "required",
   "repeated", "default" and "placeholder" properties from the Parameter
   objectType (Section 11.1) can be used as additional properties within
   the UrlTemplate object.

   For example:











Snell & Marum           Expires November 14, 2014              [Page 26]


Internet-Draft               ActivityStreams                    May 2014


             {
               "objectType": "HtmlForm",
               "mediaType": "application/x-www-form-urlencoded",
               "parameters": {
                 "foo": "http://example.org/FooProperty",
                 "bar": {
                   "objectType": "UrlTemplate",
                   "template": "http://example.org{/baz}",
                   "displayName": "Bar",
                   "required": false,
                   "repeated": false
                 }
               }
             }

   Likewise, when the value of a parameter is expected to be an instance
   of a specific MIME media type, the TypedPayload objectType
   (Section 9) can be used.

             {
               "objectType": "HtmlForm",
               "mediaType": "multipart/form-data",
               "parameters": {
                 "file": {
                   "objectType": "TypedPayload",
                   "mediaType": "image/*",
                   "repeated": true
                 }
               }
             }

12.  Authentication Object

   An Authentication Object is used by Action Handlers that require
   specific authentication options to be supported in order to carry out
   the Action.  The object is expresed as a JSON dictionary mapping
   authentication schema labels to JSON dictionaries that provide a
   specific description of properties and requirements specific to the
   scheme.












Snell & Marum           Expires November 14, 2014              [Page 27]


Internet-Draft               ActivityStreams                    May 2014


   Example Authentication details:

     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note",
       "actions": {
         "view": {
           "objectType": "ViewActionHandler",
           "method": "GET",
           "url": "http://example.org/notes/1",
           "target": "_new",
           "auth": {
             "basic": {
               "realm": "http://example.org"
             },
             "oauth": {
               "scopes": [
                 "some.oauth.scope",
                 "another.oauth.scope"
               ]
             }
           }
         }
       }
     }

   This specification does not define the authentication schemes or
   their associated properties.  Unrecognized authentication schemes MAY
   be ignored.  However, if an implementation fails to recognize any of
   the authentication schemes specified by an Action Handler, it might
   not be possible to successfully carry out the Action.

13.  Styles Object

   A Styles Object is used by EmbedActionHandlers to provide CSS style
   hints for the container within which embedded content is to be
   displayed.  The object is expressed as either a single JSON
   dictionary object mapping CSS property names to appropriate CSS
   values, or an array of JSON dictionary objects.  An optional "media"
   member can be included within the dictionary providing a CSS Media
   Query.









Snell & Marum           Expires November 14, 2014              [Page 28]


Internet-Draft               ActivityStreams                    May 2014


   Example style hints:

   {
     "objectType": "note",
     "displayName": "A simple note object",
     "content": "This is a simple note.",
     "actions": {
       "view": {
         "objectType": "EmbedActionHandler",
         "content": "Some plain text content",
         "mediaType": "text/plain",
         "style": {
           "height": "100px",
           "width": "100px",
           "box-shadow": "10px 10px 5px #888888"
         }
       }
     }
   }

   Multiple style hints for specific media query targets:

   {
     "objectType": "note",
     "displayName": "A simple note object",
     "content": "This is a simple note.",
     "actions": {
       "view": {
         "objectType": "EmbedActionHandler",
         "content": "Some plain text content",
         "mediaType": "text/plain",
         "style": [
           {
             "media": "print",
             "height": "100px",
             "width": "100px",
             "box-shadow": "10px 10px 5px #888888"
           },
           {
             "media": "screen and (orientation: landscape)",
             "height": "100px",
             "width": "100px",
             "box-shadow": "10px 10px 5px #888888"
           }
         ]
       }
     }
   }



Snell & Marum           Expires November 14, 2014              [Page 29]


Internet-Draft               ActivityStreams                    May 2014


14.  Security Considerations

   TBD

15.  IANA Considerations

   TBD

16.  Normative References

   [I-D.snell-activitystreams]
              Snell, J., "JSON Activity Streams 2.0", draft-snell-
              activitystreams-07 (work in progress), April 2014.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC6454]  Barth, A., "The Web Origin Concept", RFC 6454, December
              2011.

   [RFC6570]  Gregorio, J., Fielding, R., Hadley, M., Nottingham, M.,
              and D. Orchard, "URI Template", RFC 6570, March 2012.

   [W3C.CR-html5-20140429]
              Berjon, R., Faulkner, S., Leithead, T., Navara, E.,
              O&#039;Connor, E., and S. Pfeiffer, "HTML5", World Wide
              Web Consortium CR CR-html5-20140429, April 2014,
              <http://www.w3.org/TR/2014/CR-html5-20140429>.

   [W3C.REC-json-ld-20140116]
              Sporny, M., Kellogg, G., and M. Lanthaler, "JSON-LD 1.0",
              World Wide Web Consortium Recommendation REC-json-
              ld-20140116, January 2014,
              <http://www.w3.org/TR/2014/REC-json-ld-20140116>.

   [W3C.REC-xmlschema-2-20041028]
              Biron, P. and A. Malhotra, "XML Schema Part 2: Datatypes
              Second Edition", World Wide Web Consortium Recommendation
              REC-xmlschema-2-20041028, October 2004,
              <http://www.w3.org/TR/2004/REC-xmlschema-2-20041028>.

   [W3C.WD-CSP11-20140211]
              Barth, A., Veditz, D., and M. West, "Content Security
              Policy 1.1", World Wide Web Consortium WD WD-
              CSP11-20140211, February 2014,
              <http://www.w3.org/TR/2014/WD-CSP11-20140211>.





Snell & Marum           Expires November 14, 2014              [Page 30]


Internet-Draft               ActivityStreams                    May 2014


Appendix A.  Using Action Handlers From Other Vocabularies

   The Activity Streams 2.0 Actions mechanism is specifically designed
   to allow Action Handlers from multiple vocabularies.

A.1.  Schema.org Actions Proposal

   Based on http://www.w3.org/wiki/images/b/b9/Actionsinschema.org.pdf:

     {
       "objectType": "video",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "watch": [
           {
             "objectType": "http://schema.org/WebPageHandler",
             "url": "http://movies.example.com/player?id=123"
           },
           {
             "objectType": "http://schema.org/AndroidHandler",
             "url": "http://movies.example.com/player?id=123",
             "package": "com.movies"
           }
         ]
       }
     }

A.2.  Google's "Actions in the Inbox"

   Based on https://developers.google.com/gmail/actions/reference/
   review-action:



















Snell & Marum           Expires November 14, 2014              [Page 31]


Internet-Draft               ActivityStreams                    May 2014


     {
       "objectType": "note",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "review": {
           "objectType": "http://schema.org/ReviewAction",
           "review": {
             "objectType": "http://schema.org/Review",
             "itemReviewed": {
               "objectType": "http://schema.org/FoodEstablishment",
               "name": "Joe's Diner"
             },
             "reviewRating": {
               "objectType": "http://schema.org/Rating",
               "bestRating": "5",
               "worstRating": "1"
             }
           },
           "handler": {
             "objectType": "http://schema.org/HttpActionHandler",
             "url": "http://reviews.com/review?id=123",
             "requiredProperty": {
               "objectType": "http://schema.org/Property",
               "name": "review.reviewRating.ratingValue"
             },
             "method": "http://schema.org/HttpRequestMethod/POST"
           }
         }
       }
     }

A.3.  Mixing Vocabularies


















Snell & Marum           Expires November 14, 2014              [Page 32]


Internet-Draft               ActivityStreams                    May 2014


     {
       "objectType": "video",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "watch": [
           {
             "objectType": "ViewActionHandler",
             "url": "http://movies.example.com/player?id=123",
             "target": "_new"
           },
           {
             "objectType": "http://schema.org/AndroidHandler",
             "url": "http://movies.example.com/player?id=123",
             "package": "com.movies"
           }
         ]
       }
     }

A.4.  Example Drawing From Multiple Vocabularies

     {
       "objectType": "video",
       "displayName": "A Movie!",
       "displayName": "A simple note object",
       "content": "This is a simple note.",
       "actions": {
         "watch": [
           {
             "objectType": "EmbedActionHandler",
             "displayName": "HD",
             "mediaType": "video/mpeg",
             "url": "http://cdn.example.org?id=123amp;fmt=HD",
           },
           {
             "objectType": "EmbedActionHandler",
             "displayName": "SD",
             "mediaType": "video/mpeg",
             "url": "http://cdn.example.org?id=123&fmt=SD",
           },
           {
             "objectType": "application",
             "displayName": "Watch on Netflix",
             "url": "http://netflix.com..."
           }
         ],
         "like": {



Snell & Marum           Expires November 14, 2014              [Page 33]


Internet-Draft               ActivityStreams                    May 2014


           "objectType": "EmbedActionHandler",
           "mediaType": "text/html",
           "url": "http://www.facebook.com/plugins/like.php...",
           "style": {
             "width": "150px",
             "height": "50px"
           }
         },
         "share": [
           {
             "objectType": "ViewActionHandler",
             "displayName": "Twitter",
             "url": "https://twitter.com/share?url=...",
             "target": "dialog"
           },
           {
             "objectType": "ViewActionHandler",
             "displayName": "Facebook",
             "url": "https://www.facebook.com/sharer/sharer.php?u=...",
             "target": "dialog"
           }
         ],
         "save": [
           {
             "objectType": "service",
             "id": "http://getpocket.com",
             "displayName": "Pocket",
             "context": {
               "url": "http://example.org/movie?id=123",
               "title": "A Movie!",
               "tags": "foo, bar, baz"
             }
           },
           {
             "objectType": "service",
             "id": "http://instapaper.com",
             "displayName": "Instapaper",
             "context": {
               "url": "http://example.org/movie?id=123",
               "title": "A Movie!",
               "selection": "An action movie!"
             }
           }
         ],
         "review": {
           "objectType": "HttpActionHandler",
           "displayName": "Rate this movie!",
           "url": "http://review.example.org/movie?id=123",



Snell & Marum           Expires November 14, 2014              [Page 34]


Internet-Draft               ActivityStreams                    May 2014


           "method": "POST",
           "expects": {
             "objectType": "HtmlForm",
             "mediaType": "application/x-www-form-urlencoded",
             "parameters": {
               "rating": {
                 "maxInclusive": 5,
                 "minInclusive": 0,
                 "fractionDigits": 2,
                 "totalDigits": 3
                 "type": "float",
                 "displayName": "Rating"
               },
               "comments": {
                 "displayName": "Comments",
                 "type": "string",
                 "required": false
               }
             }
           }
         }
       }
     }

Authors' Addresses

   James M Snell
   IBM

   Email: jasnell@gmail.com


   Matthew Marum
   SugarCRM

   Email: mgmarum@gmail.com















Snell & Marum           Expires November 14, 2014              [Page 35]


Html markup produced by rfcmarkup 1.128b, available from https://tools.ietf.org/tools/rfcmarkup/