External images via _canonical_uri

1

If I create an image/jpeg tiddler and point to an external image using the _canonical_uri field, say https://upload.wikimedia.org/wikipedia/commons/9/91/Foro_Romano_Forum_Romanum_Roman_Forum_(8043630550).jpg

The image is displayed in the tiddler.

But if I try and display that image tiddler in another tiddler via the image link syntax it fails. What am I doing wrong?

[img[external_image_tiddler]]

Thanks

2

Hi @myfta

It just works on tiddlywiki.com, so I guess the problem is local to your wiki.
Are you using lazy loading? Or maybe a CORS problem?

Fred

4

I did think it was my Brave browser, but I have checked on Tiddlyhost and the browser works OK there and I don’t have the issue.

My wiki is on Node.js

I have tried starting the wiki with the LazyLoad options https://tiddlywiki.com/static/LazyLoading.html but that make no difference.

If I create an image tiddler and the _canonical_uri points to the url of the image it loads OK. Where it fails is if I then try to link to that image tiddler with [img[image tiddler]] in a new tidddler.

This ought to be straigtforward. Maybe the issue is “Images do not load in Node.js” and is a bug rather than a configuration issue.

5

Maybe I’m misunderstanding here? I’ve no problem using _canonical_uri in my node setup

Here is my .tid with _canonical_uri set:

_canonical_uri: https://en.wikipedia.org/static/images/icons/wikipedia.png
created: 20250804015355568
modified: 20250804015512609
tags: scratch
title: scratch12: _canonical_uri
type: image/png

And then you can transclude that tid to get the image:

{{scratch12: _canonical_uri}} but you cant set the size

I’m able to call it as an image (and set size!) like so: [img width=54 height=42 [scratch12: _canonical_uri]]

2025-08-04T12:27:14_9b7c32dd
2025-08-04T12:27:14_9b7c32dd999Ă—304 118 KB

My testing is with Node TW 5.3.6

edit/appendum: I also have (ages ago, and forgot it was there to re-test/demonstrate), a category tid with it’s icon field set to the name of a tid with an image via _canonical_uri. The icon correctly loads for that category tid.

6

Thanks, this has proved most helpful and seems to have uncovered a glitch in TW5.

Using my image source, the transclusion method {{scratch12: _canonical_uri}} works as expected but calling the img [img width=54 height=42 [scratch12: _canonical_uri]] failed.

So I deleted both my image tidller and the tiddler that calls the image and re-created them. Strangely it now works.

I had checked the tiddler type, brackets and any spurious spaces.

7

This syntax, with the colon, is completely new to me, and I don’t see it in the documentation. Where is it in the docs?

Thanks!

8

Quoting @nemo,

title: scratch12: _canonical_uri

scratch12: _canonical_uri is literally the tiddler’s title, not a new syntax.

Fred

9

Oh, good. The FOMO was overwhelming.

10

odd indeed, but good to hear it works now. Let us know if you replicate the original glitch to help identify what was originally happening!