Inline images aren't displaying inline

[brentkearney]

Hi, thanks so much for your work on sparkpost_rails!

I'm trying to include inline images like this:

message[:attachments].each do |ad|
  attachments.inline[ad.original_filename] = {
     mime_type: ad.content_type,
     content: File.read(ad.tempfile),
     cid: 'some-name'
  }
end

However, the message arrives with a randomly generated Content-Id rather than the specified cid: parameter, and a missing image icon appears where the <img> tag is in HTML, with the attachment at the bottom of the message.

In this case, the email is received from Sparkpost webhook, so the content-id is already set in the incoming email. I parse it out, and then use that value in the cid: parameter in attachments.inline[] = {}. If it were actually used, the image would display inline where specified by the <img> tag, but the cid parameter seems to be ignored.

[brentkearney]

I figured it out. To specify the Content-Id, use:

attachments.inline[filename].header['content-id'] = your-custom-id

Cheers