Add support for exporting canvases and attachments

[samdev11]

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Slack recently launched a new feature, Canvases. It looks like these are not currently being exported by slackdump.

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It would be great to add support to Slackdump for Canvases, so that the content and attachments can be exported.

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[rusq]

Hey @samdev11 , currently there's no publicly available APIs to scrape canvases for the account, so it would not be possible at this point. My test workspaces don't have this feature, so I can't even test this. Most likely they are using the internal edge apis, implementing which is currently on on the radar.

I'll let this issue dangle until the smoke clears around those canvases.

[softyoda]

Hi, is the canvas API still no publicly available ? We wish to use slack new canvas but also perpetuate our data easily.

[rusq]

Hey @softyoda , it doesn't look like it, there's nothing in this list: https://api.slack.com/methods