Thanks!

I've just corrected the documentation

{
   action: {},
   order,
   grouporder,
   submenu,
}

{
   action: {
   	   submenu
   },
   order,
   grouporder,
}

Oh dear.
I just figured it out by stumbling upon this [url=https://www.mediamonkey.com/forum/viewtopic.php?p=458942]other forum question [/url]and seeing the code there.

The documentation page [url=https://www.mediamonkey.com/wiki/Getting_Started_%28Addons%29#Adding_actions_to_menus]here[/url] says that submenu should be defined here in the hierarchy:
[code]
{
action: {},
order,
grouporder,
submenu,
}
[/code]

But those docs are incorrect, it should be:
The documentation page here says that submenu should be defined here in the hierarchy:
[code]
{
action: {
submenu
},
order,
grouporder,
}
[/code]

window.menus.tracklistMenuItems.push({
    action: {
        title: 'Auto crossfade settings',
        // icon: String,
        visible: () => uitools.getCanEdit(),
    },
    // order: Number,          // Required
    // grouporder: Number,     // Required
    submenu: [
        {
            action: {title: 'Selected tracks'},
            submenu: [
                {action: actions.autoCrossfadeTrack},
                {action: actions.alwaysCrossfadeTrack},
                {action: actions.neverCrossfadeTrack}
            ]
        },
        {
            action: {title: 'Entire <insert name> genre'},
            submenu: [
                {action: actions.autoCrossfadeTrack},
                {action: actions.alwaysCrossfadeTrack},
                {action: actions.neverCrossfadeTrack}
            ]
        },
        {
            action: {title: 'Entire <insert name> mood'},
            submenu: [
                {action: actions.autoCrossfadeTrack},
                {action: actions.alwaysCrossfadeTrack},
                {action: actions.neverCrossfadeTrack}
            ]
        },
        {
            action: {title: 'Entire <insert name> collection'},
            submenu: [
                {action: actions.autoCrossfadeTrack},
                {action: actions.alwaysCrossfadeTrack},
                {action: actions.neverCrossfadeTrack}
            ]
        },
    ]
})

I've been trying to create a submenu in the tracklist menu, however, I can't figure out how to make it work.
I can make single items work that aren't in a submenu, but if I give it the property of [b]submenu [/b]with an array (like specified in [url=https://www.mediamonkey.com/wiki/Getting_Started_%28Addons%29#Adding_actions_to_menus]these docs[/url]), it's stays as a single item with no menu of children that fold out.

[b]ie. [/b]in the code below, all I get is a single item named "Auto crossfade settings".
Please note that I've tried adding in order and grouporder values, and removing the 3rd level of submenu, but haven't seen any difference.

I'm adding this code in [b]trackListView_add.js[/b]

[code]
window.menus.tracklistMenuItems.push({
action: {
title: 'Auto crossfade settings',
// icon: String,
visible: () => uitools.getCanEdit(),
},
// order: Number, // Required
// grouporder: Number, // Required
submenu: [
{
action: {title: 'Selected tracks'},
submenu: [
{action: actions.autoCrossfadeTrack},
{action: actions.alwaysCrossfadeTrack},
{action: actions.neverCrossfadeTrack}
]
},
{
action: {title: 'Entire <insert name> genre'},
submenu: [
{action: actions.autoCrossfadeTrack},
{action: actions.alwaysCrossfadeTrack},
{action: actions.neverCrossfadeTrack}
]
},
{
action: {title: 'Entire <insert name> mood'},
submenu: [
{action: actions.autoCrossfadeTrack},
{action: actions.alwaysCrossfadeTrack},
{action: actions.neverCrossfadeTrack}
]
},
{
action: {title: 'Entire <insert name> collection'},
submenu: [
{action: actions.autoCrossfadeTrack},
{action: actions.alwaysCrossfadeTrack},
{action: actions.neverCrossfadeTrack}
]
},
]
})
[/code]