Custom "Cannot Find Host" message when FD cannot find a text file.

[Lylythii]

Concept

For self hosted source content, files, or custom Git repositories. Authors could provide a host.txt file or similar.

• In the event the modpack cannot find this file. (Website is down or is moving. Repository disappears. Etc.) FD will display a custom fallback message to inform the end user as to why. Allowing authors to communicate to the end-user while the source is down or in maintenance. (Perhaps this reason could additionally support using remote text files instead of a static message. So it can be changed.)
• Host files could contain a bool to mark the pack as offline, & to cease all attempts at file downloads. Assuming the host is available, but intentionally disabled for one reason or another. (This could be bypassed by manually changing a flag in modpack.json if the end user wishes to risk broken installs on their own terms.)

{
    "hostOffline": true
}

true = pretend to be offline.
false = allow downloads.

• Optionally. modpack.json should be able to allow offline play. Without attempting to install any files until the host is found again. Effectively "freezing" modpack updates. & displaying "Close Game" & "Continue Without Host" buttons. (allowOfflineLaunch)
• Offline Play should work even if the host is available. If users wish to launch outdated pack updates that are no longer available. Effectively disabling FD entirely. (Excluding a "You are Offline" message on launch, to inform the end user.)

This message, & a link to the host text file, should be specified in the modpack.json file. Similar to below;

{
    "packName": "Pack Name",
    "icon": {
        "path": "icon.png"
   },
    "host": {
        "hostFile": "website_url.host.txt",
        "hostOfflineReason": "This modpacks website is currently down for maintenance. Downloads are unavailable.",
        "hostOfflineReasonRemote": "website_url.reason.txt",
        "allowOfflineLaunch": false
   }
}

Definitions

• hostFile Remote text file. Containing a true/false bool. false = pack can connect. allow downloads. true = pretend to be offline. Can't find this file due to being offline? Treat it as true. Offline.
• hostOfflineReason Static fallback reason for why the pack cannot launch.
• hostOfflineReasonRemote Remote text file with a custom message to display why the pack cannot launch.
• allowOfflineLaunch Allow the pack to launch? false = disable launching. true = allow the user to continue launching.

Is this desperately needed? No, but a way to inform the user that the modpacks source is "currently unavailable", & why, helps reduce confusion.

End Goal

• Ability for the author to freeze updates/downloads entirely.
• Allow users to bypass this manually, accepting the risks.
• Inform users why the modpack is unavailable. In the event the Authors website is down, or downloads are frozen.