Template talk:ImageLink

This template seems to be producing this error in certain places:

Error: must specify an image in the first line

--Anaminus 23:04, 15 September 2011 (UTC)

Which places? What arguments cause that to happen?

NXTBoy (talk • contribs)

06:52, 16 September 2011 (UTC)

I can see the problem pages, but I can't reproduce it on a new page. Looks like either a caching issue (good), or a template overuse issue (very bad).

NXTBoy (talk • contribs)

16:06, 16 September 2011 (UTC)

Compare Template:ObjectPage with RBX.lua.Instance (Object). Not sure why the second doesn't work.

NXTBoy (talk • contribs)

16:09, 16 September 2011 (UTC)

The Template:Derived_classes/link page throws Error: invalid title in link at line 3 if that helps.--Anaminus 18:41, 16 September 2011 (UTC)

Nope. That's just because the template has no default parameters. Besides, that's not the error we're getting. Try adding {{derived classes|Instance}} to a new page. It works fine.

NXTBoy (talk • contribs)

19:58, 16 September 2011 (UTC)

Doesn't ImageLink require an image parameter? Template:Object/image doesn't seem to do that. --Anaminus 18:41, 16 September 2011 (UTC)

Yes, but it's optional. The image parameter adds Image: to the front of the url. I needed to put the whole URL in though, so I bodged it so that it uses the first unnamed parameter if no image parameter is specified.

NXTBoy (talk • contribs)

19:58, 16 September 2011 (UTC)

Crap. Looks like a template limit issue. I'll keep testing...

NXTBoy (talk • contribs)

20:24, 16 September 2011 (UTC)

I found out why there are errors. For the ClassLink page, I initially used the Template:ifexist template to check if the image existed, but it still returned yes despite it not existing. See here:

{{ifexist|Image:nonexistentimage|yes|no}} -> no

The errors are appearing because the the images generated from this still don't exist. --Anaminus 20:31, 16 September 2011 (UTC)

It's a casing issue. Try {{ifexist|Image:Nonexistentimage|yes|no}}. That works properly. This doesn't seem to be the cause of the problem.

It's a template nesting issue

It's definitely a template nesting issue. Try testing:

{{derived classes|Instance}}

Now try

{{1x|{{derived classes|Instance}}}}

And

{{1x|{{1x|{{derived classes|Instance}}}}}}

And keep going till it breaks. It just happened that we were right on the edge of the template limit. One more level of indirection (getting a derived image) results in a failure. Until I work out how to solve it, I've made it stick a ? where the error message was.

Here's a demo, nesting {{1x}}:

• Nest 40 templates: Level 40 here.

• Nest 41 templates: This is level 41.

This behaviour is happening inside {{ifexist}}.

NXTBoy (talk • contribs)

21:07, 16 September 2011 (UTC)