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Revision as of 09:43, 27 July 2011

Contents

Architectural Overview

The PlaylistManager service provides the ability to create and maintain playlists.

The PlaylistManager service provides access to a list of playlists, which in turn, contain a list of tracks.

Using the PlaylistManager service you can read, insert and delete playlists as well as read, insert and delete tracks from an individual playlist. Each playlist and track within a playlist is given a unique id.

To insert a playlist, provide the id of the playlist you wish to insert 'after' and the associated metadata, (name, description and image id). An empty playlist is inserted into the correct position and the id of the new playlist is returned. To insert in the first position, insert after the special id of 0.

To insert a track, provide the id of the playlist and the id of the track you wish to insert 'after' and the associated udn and metadata id. The track is inserted and the id of the new track is returned. To insert in the first position. insert after the special id of 0. If the track originated from a media server the udn should contain the udn of the media server and the metadata id contain the id contained in the DidlLite of the track. Otherwise the udn should be empty and the metadata id contain DidlLite describing of the track.

There are two ways to read the list of playlists or the list of tracks in a playlist. The first reads a single entry and the second reads a list of entries.

There are two ways to delete the playlists or the the tracks in a playlist. The first deletes a single entry and the second deletes a list of entries.

IdArray and TokenIdArray

The PlaylistManager service has two eventide state variable called IdArray and TokenArray. Both arrays are base64 encoded arrays of 32 bit, big endian unsigned integers. Each Id and Token represents a playlist in the list of playlists. An empty array indicates an empty list if playlists. A Change in Token for a playlist indicates that the playlist contents has changed.

Playlist IdArray

The obtain a playlist's IdArray, provide the id of the playlist to the action PlaylistReadArray. The IdArray returned is a base64 encoded array of 32 bit, big endian unsigned integers. Each Id represents a track in the playlist. An empty IdArray indicates an empty playlist.

Events

A short while (approx 300ms) after any change to the list of playlists, the PlaylistManager will event all subscribers the current IdArray and TokenArray. The eventing of these state variables is moderated to prevent excessive updates.

A short while (approx 300ms) after any changes to a playlist, the PlaylistManager will event all subscribers the current TokenArray. The eventing of this state variable is moderated to prevent excessive updates.

Polling

For control points that can't subscribe to events, two additional actions are provided. The first, PlaylistArrays, reads the IdArray and TokenArray directly. This action also returns an ArraysToken, which should be saved and periodically passed to a second action, PlaylistArraysChanged, which reports whether or not your copy of IdArray and TokenArray are out of date. If they are, calling PlaylistArrays again will ensure you have up to date versions.

Technical Details 

   Domain  : av.openhome.org
   Name    : PlaylistManager
   Version : 1

PlaylistManager Service Description (XML) 

<?xml version="1.0" encoding="utf-8"?>
 
<scpd xmlns="urn:schemas-upnp-org:service-1-0">
 
    <specVersion>
        <major>1</major>
        <minor>0</minor>
    </specVersion>
 
    <actionList>
        <action>
            <name>Metadata</name>
            <argumentList>
                <argument>
                    <name>Metadata</name>
                    <direction>out</direction>
                    <relatedStateVariable>Metadata</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
 
        <action>
            <name>ImagesXml</name>
            <argumentList>
                <argument>
                    <name>ImagesXml</name>
                    <direction>out</direction>
                    <relatedStateVariable>ImagesXml</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
 
        <action>
            <name>PlaylistReadArray</name>
            <argumentList>
                <argument>
                    <name>Id</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
                <argument>
                    <name>Array</name>
                    <direction>out</direction>
                    <relatedStateVariable>IdArray</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>PlaylistReadMetadata</name>
            <argumentList>
                <argument>
                    <name>IdList</name>
                    <direction>in</direction>
                    <relatedStateVariable>IdList</relatedStateVariable>
                </argument>
                <argument>
                    <name>Metadata</name>
                    <direction>out</direction>
                    <relatedStateVariable>Metadata</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>PlaylistRead</name>
            <argumentList>
                <argument>
                    <name>Id</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
                <argument>
                    <name>Name</name>
                    <direction>out</direction>
                    <relatedStateVariable>Name</relatedStateVariable>
                </argument>
                <argument>
                    <name>Description</name>
                    <direction>out</direction>
                    <relatedStateVariable>Description</relatedStateVariable>
                </argument>
                <argument>
                    <name>ImageId</name>
                    <direction>out</direction>
                    <relatedStateVariable>ImageId</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>PlaylistUpdate</name>
            <argumentList>
                <argument>
                    <name>Id</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
                <argument>
                    <name>Name</name>
                    <direction>in</direction>
                    <relatedStateVariable>Name</relatedStateVariable>
                </argument>
                <argument>
                    <name>Description</name>
                    <direction>in</direction>
                    <relatedStateVariable>Description</relatedStateVariable>
                </argument>
                <argument>
                    <name>ImageId</name>
                    <direction>in</direction>
                    <relatedStateVariable>ImageId</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>PlaylistInsert</name>
            <argumentList>
                <argument>
                    <name>AfterId</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
                <argument>
                    <name>Name</name>
                    <direction>in</direction>
                    <relatedStateVariable>Name</relatedStateVariable>
                </argument>
                <argument>
                    <name>Description</name>
                    <direction>in</direction>
                    <relatedStateVariable>Description</relatedStateVariable>
                </argument>
                <argument>
                    <name>ImageId</name>
                    <direction>in</direction>
                    <relatedStateVariable>ImageId</relatedStateVariable>
                </argument>
                <argument>
                    <name>NewId</name>
                    <direction>out</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>PlaylistDeleteId</name>
            <argumentList>
                <argument>
                    <name>Value</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>PlaylistDeleteAll</name>
        </action>
        <action>
            <name>PlaylistsMax</name>
            <argumentList>
                <argument>
                    <name>Value</name>
                    <direction>out</direction>
                    <relatedStateVariable>PlaylistsMax</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>TracksMax</name>
            <argumentList>
                <argument>
                    <name>Value</name>
                    <direction>out</direction>
                    <relatedStateVariable>TracksMax</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>PlaylistArrays</name>
            <argumentList>
                <argument>
                    <name>Token</name>
                    <direction>out</direction>
                    <relatedStateVariable>ArraysToken</relatedStateVariable>
                </argument>
                <argument>
                    <name>IdArray</name>
                    <direction>out</direction>
                    <relatedStateVariable>IdArray</relatedStateVariable>
                </argument>
                <argument>
                    <name>TokenArray</name>
                    <direction>out</direction>
                    <relatedStateVariable>TokenArray</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>PlaylistArraysChanged</name>
            <argumentList>
                <argument>
                    <name>Token</name>
                    <direction>in</direction>
                    <relatedStateVariable>ArraysToken</relatedStateVariable>
                </argument>
                <argument>
                    <name>Value</name>
                    <direction>out</direction>
                    <relatedStateVariable>IdArrayChanged</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
 
        <action>
            <name>Read</name>
            <argumentList>
                <argument>
                    <name>Id</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
                <argument>
                    <name>TrackId</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
                <argument>
                    <name>Metadata</name>
                    <direction>out</direction>
                    <relatedStateVariable>Metadata</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>ReadList</name>
            <argumentList>
                <argument>
                    <name>Id</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
                <argument>
                    <name>TrackIdList</name>
                    <direction>in</direction>
                    <relatedStateVariable>IdList</relatedStateVariable>
                </argument>
                <argument>
                    <name>TrackList</name>
                    <direction>out</direction>
                    <relatedStateVariable>TrackList</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>Insert</name>
            <argumentList>
                <argument>
                    <name>Id</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
                <argument>
                    <name>AfterTrackId</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
                <argument>
                    <name>Udn</name>
                    <direction>in</direction>
                    <relatedStateVariable>Udn</relatedStateVariable>
                </argument>
                <argument>
                    <name>MetadataId</name>
                    <direction>in</direction>
                    <relatedStateVariable>MetadataId</relatedStateVariable>
                </argument>
                <argument>
                    <name>NewTrackId</name>
                    <direction>out</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>DeleteId</name>
            <argumentList>
                <argument>
                    <name>TrackId</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
                <argument>
                    <name>Value</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
        <action>
            <name>DeleteAll</name>
            <argumentList>
                <argument>
                    <name>TrackId</name>
                    <direction>in</direction>
                    <relatedStateVariable>Id</relatedStateVariable>
                </argument>
            </argumentList>
        </action>
    </actionList>
 
    <serviceStateTable>
 
        <stateVariable sendEvents="yes">
            <name>Metadata</name>
            <dataType>string</dataType>
        </stateVariable>
        <stateVariable sendEvents="yes">
            <name>ImagesXml</name>
            <dataType>string</dataType>
        </stateVariable>
        <stateVariable sendEvents="yes">
            <name>IdArray</name>
            <dataType>bin.base64</dataType>
        </stateVariable>
        <stateVariable sendEvents="yes">
            <name>TokenArray</name>
            <dataType>bin.base64</dataType>
        </stateVariable>
        <stateVariable sendEvents="yes">
            <name>PlaylistsMax</name>
            <dataType>ui4</dataType>
        </stateVariable>
        <stateVariable sendEvents="yes">
            <name>TracksMax</name>
            <dataType>ui4</dataType>
        </stateVariable>
 
        <stateVariable sendEvents="no">
            <name>PlaylistList</name>
            <dataType>string</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>Id</name>
            <dataType>ui4</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>IdList</name>
            <dataType>string</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>Name</name>
            <dataType>string</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>Description</name>
            <dataType>string</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>ImageId</name>
            <dataType>ui4</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>TrackList</name>
            <dataType>string</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>Udn</name>
            <dataType>string</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>MetadataId</name>
            <dataType>string</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>ArraysToken</name>
            <dataType>ui4</dataType>
        </stateVariable>
        <stateVariable sendEvents="no">
            <name>IdArrayChanged</name>
            <dataType>boolean</dataType>
        </stateVariable>
    </serviceStateTable>
</scpd>
Retrieved from "http://wiki.openhome.org/wiki/Av:Developer:PlaylistManagerService"