Images from Gliffy embed not rendering

(Geoff Bowers) #1

Are there any specific reasons why an image wouldn’t be rendered within a post? Blocking headers… something?

I’m trying to embed an image from Gliffy diagramming service. When the digram is updated through Gliffy I want the image updated automatically on the forum. They have an image sharing service for exactly this purpose.

It generates the following URL for my test image:

Note, it doesn’t render as an image in Discourse.

But it does allow you to:

  • link to the image and see, download, etc within the browser
  • link and unfurl in services like Slack

I can “Copy Image” from the browser and paste into Discourse no troubles:


Any help much appreciated!

(Matt Palmer) #2

Interesting… I’m about 99% sure the problem is that Gliffy appears to respond to HEAD requests with a 404, which is waaaaaay wrong. Like, “bro do u even RFC?!?”-grade wrong. You can work around that by using a proper markdown “include image” link, like this:

![my image](

Which renders correctly:

my image

I have my suspicions that, even if you could get Gliffy to fix their bone-headed handling of HEAD requests, though, you probably won’t get the result you want. Discourse usually downloads externally-linked images and replaces them with inline versions, to avoid the problem a lot of forums have of old posts being graveyards of broken image links (and also to avoid inadvertently putting load on other people’s servers). There might be a setting somewhere to turn off downloads for a whole site, or some magical incantation to disable it for a given image link, but I don’t know what that would be, if it exists.

Myself, I ditched Gliffy a while ago and am a happy user of There’s ways to embed whole diagrams, and I have a dream, one day, that I’ll get around to building a plugin to provide a little “Edit with” link next to such diagrams, at which point I will immediately expire in a paroxym of ecstasy.

(Geoff Bowers) #3

I like both Lucidchart and but I suspect I’ve been a little bit naive in my thoughts about a dynamic image; i remember that Discourse downloads and localises the image. Turns out that getting the image to update post edit has an awkward workflow at best.

Looks like you would need some sort of callback that would magically rebake the post with a new image version. Or would i be better off thinking about some sort of IFRAME style embed that always looks at the remote server for the image?

I’ll take another look at the Embed diagram in post option you mention; at first glance it looked like gobbledygook to me :slight_smile: