Add MessageExtensions.AttachmentLayout type with grid support

[Copilot]

Introduce a new messaging extension-specific attachment layout type with grid support alongside list, aligning with teams.ts PR #381.

Changes

• New MessageExtensions.AttachmentLayout: Created a new type specifically for messaging extensions with List and Grid constants
• MessageExtensions.Result: Updated to use the new MessageExtensions.AttachmentLayout type instead of Api.Attachment.Layout
• Attachment.Layout: Preserved the original type with List and Carousel constants unchanged
• Samples: Updated sample code to use the new MessageExtensions.AttachmentLayout type
• Documentation: Added comprehensive README for the MessageExtensions sample with Teams manifest configuration instructions

Usage

var result = new MessageExtensions.Result
{
    Type = ResultType.Result,
    AttachmentLayout = MessageExtensions.AttachmentLayout.Grid,  // New messaging extension-specific type
    Attachments = attachments
};

This approach separates concerns:

• General Attachment.Layout keeps List and Carousel for general attachments
• Messaging-extension-specific MessageExtensions.AttachmentLayout has List and Grid for messaging extensions

Documentation

The new README (Samples/Samples.MessageExtensions/README.md) provides:

• Complete setup instructions for Azure Bot Service
• Teams app manifest configuration with all message extension commands
• Local development setup with dev tunnels or ngrok
• Detailed usage examples for all message extension types
• Troubleshooting guide

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Original prompt

can you change AttachmentLayout to be list | grid instead of list | carousel. Link microsoft/teams.ts#381 in the PR description.

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[heyitsaamir]

@copilot remove the tests. they're not helpful.

[Copilot]

@copilot remove the tests. they're not helpful.

Removed in 2a95369

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• token.botframework.com
  • Triggering command: /usr/share/dotnet/dotnet exec --runtimeconfig /home/REDACTED/work/teams.net/teams.net/Tests/Microsoft.Teams.Apps.Tests/bin/Debug/net9.0/Microsoft.Teams.Apps.Tests.runtimeconfig.json --depsfile /home/REDACTED/work/teams.net/teams.net/Tests/Microsoft.Teams.Apps.Tests/bin/Debug/net9.0/Microsoft.Teams.Apps.Tests.deps.json /home/REDACTED/work/teams.net/teams.net/Tests/Microsoft.Teams.Apps.Tests/bin/Debug/net9.0/testhost.dll --port 40369 --endpoint 127.0.0.1:040369 --role client --parentprocessid 3842 --telemetryoptedin false (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[heyitsaamir]

@copilot revert this change. Then introduce a NEW type called MessagingExtensionAttachmentLayout, and use THAT for the attachmentLayout in MessagingExtensionResult. Don't forget to export types as needed in __init__s.

[Copilot]

@copilot revert this change. Then introduce a NEW type called MessagingExtensionAttachmentLayout, and use THAT for the attachmentLayout in MessagingExtensionResult. Don't forget to export types as ne...

Done in 5182bb1. Reverted Attachment.Layout to have Carousel, created new MessageExtensions.AttachmentLayout type with List and Grid, and updated Result.cs and sample code to use the new type.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• token.botframework.com

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

[heyitsaamir]

I attest that no verification is required

[rido-min]

@copilot add a README with instructions to configure the Teams Manifest to validate the MessageExtensions sample

[Copilot]

@copilot add a README with instructions to configure the Teams Manifest to validate the MessageExtensions sample

Added comprehensive README in 3d75a6a with:

• Complete Teams manifest configuration for all message extension features
• Azure Bot Service setup instructions
• Local development setup with dev tunnels/ngrok
• Step-by-step app installation guide
• Usage examples and troubleshooting

[rido-min]

@heyitsaamir When using AttachmentLayout = Microsoft.Teams.Api.MessageExtensions.AttachmentLayout.Grid, I got an invisible grid (but clickable).

Can we update the sample code to show how to use this new layout?

[heyitsaamir]

@heyitsaamir When using AttachmentLayout = Microsoft.Teams.Api.MessageExtensions.AttachmentLayout.Grid, I got an invisible grid (but clickable).

Can we update the sample code to show how to use this new layout?

@rido-min As discussed offline, the reason is that the thumbnail field is required for it ti show up in Grid mode