When implementing a Sonos Music API, how do I get a menu listing "collection" items, to display a "Play All" button? - sonos

Question

What I'm trying to achieve
I want to display the same "Play All" menu item I get when listing tracks (menus with itemType=trackList) for menus of other itemTypes e.g. Playlists. Is that possible?
So for example, representing each menu as a nested list, I want:
Collection 1
Play All <---- I don't get this one!
Playlist 1
Play All <-- I get this
Track 1
Track 2
...
Playlist 2
Play All <-- I get this
Track 1
Track 1
...
It's fine if this behaviour is not possible, but I just wanted to double-check.
What the docs say
According to the Sonos API docs, you can make other itemTypes playable by setting canPlay=true. In fact, it specifically mentions my use case:
The canPlay flag is used to indicate that the collection can be queued up for playback in its entirety. In order to accomplish this, the client will call getMetadata passing in a Boolean parameter “recursive” set to true. This will return a flattened list of all mediaItem elements in the collection. For example, “canPlay” might be true for a collection that represents a playlist of tracks...
When I set canPlay=true I'm able to press and hold on the Collection in the prior menu, and have a menu popup that let's me play everything that way, but I don't get an actual "Play All" icon in the subsequent menu. Is that intended, or is there any way to display the "Play All" icon?
The SMAPI itemTypes page says:
a mediaCollection of itemType trackList with a canEnumerate = true will enable the "All Tracks" node once you browse into the container, as shown below
Is that the only itemType that this will work for?
My getMetadata Responses
In case it's useful, here's my getMetadata responses:
getMetadata call that displays the menu containing the Collection:
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Body>
<getMetadataResponse xmlns="http://www.sonos.com/Services/1.1">
<getMetadataResult>
<index>0</index>
<count>10</count>
<total>10</total>
...
<mediaCollection>
<id>collections:134</id>
<itemType>collection</itemType>
<displayType>standardView</displayType>
<title>Collection 1</title>
<summary>Collection 1 Summary</summary>
<canPlay>true</canPlay>
<albumArtURI>https://path/to/album_art.jpg</albumArtURI>
</mediaCollection>
...
</getMetadataResult>
</getMetadataResponse>
</soap:Body>
</soap:Envelope>
getMetadata call that lists the Collection's Playlists:
<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
<soap:Body>
<getMetadataResponse xmlns="http://www.sonos.com/Services/1.1">
<getMetadataResult>
<index>0</index>
<count>1</count>
<total>1</total>
<mediaCollection>
<id>collections:134:playlists:506</id>
<itemType>trackList</itemType>
<displayType>standardView</displayType>
<title>Playlist 1</title>
<summary>Playlist 1 summary</summary>
<canPlay>true</canPlay>
<albumArtURI>http://path/to/album_art.jpg</albumArtURI>
</mediaCollection>
</getMetadataResult>
</getMetadataResponse>
</soap:Body>
</soap:Envelope>

Answer 1

It sounds like what you are trying to display is the "All Songs" node at the top of a collection of tracks. As you mention, setting "canPlay" equal to true will cause a "Play All" node to be displayed, and this should work for any mediaCollection regardless of container type. Similarly, setting "canEnumerate" to true should result in the "All Tracks" node being displayed at the the top of a container for any mediaCollection. There is unfortunately no way to display a Play all button at the top of a container.