MODx 1.0.4: Caching problem - possibly with Ditto or Wayfinder

I'm a web designer who inherited a MODx CMS installation. I'll do my best to explain this issue so that you can help me. After explaining the problem I'll upload five graphics which hopefully will supply info that helps you help me.

Most of the pages in our web site have sidebars (sideboxes?) that are accessed in several templates using Ditto. Wayfinder is used on our archive pages to retrieve the requested page.

I have had issues where cached pages will intermittently lose their sidebars. I don't know if this is a bug in MODx. However, I can fix the problem easily by clearing the MODx cache. In my quest for a permanent fix I decided to change the setting for all our archive pages to 'cachable = no'. So far this has produced a definite improvement and may well have solved the problem.

Unfortunately it introduced a new problem but only on pages that are accessed by Wayfinder (e.g. http://staging.samswebstop.com/news/archives/school-funding.html?start=8). Ditto may be involved as well and I will show you template syntax shortly.

I am hoping that if I show you the right information a light may go on in your minds leading to a solution or something I can try.

Here's what I'm attaching:
1. 2 web pages that show the problem. The first page is NOT missing the sidebars. That page is accessed by its URL alias alone. The second page IS missing the sidebars and has different URL syntax (adds ?start=n).

2. Same two web pages but with source code as seen by 'Firebug'. It shows HTML when data is present and when missing.

3. This shows a typical resource page. You'll see it invoking a chunk and also you'll see TVs designating the required sidebars.

4. This is the template code.

5. This is the code for the chunk above.

I'd like to remind you that this problem is caused 100% by the fact that the initial page is designated as uncached.

I'll keep my fingers crossed that the 'light goes on' for someone reading this.

Thank you for staying with me long enough to read all this.

--- Sam

First thing I would try is calling the snippets uncached, that is use [!snippetname!] instead of [[snippetname]]

Quote from: breezer at May 17, 2013, 12:05 PM

First thing I would try is calling the snippets uncached, that is use [!snippetname!] instead of [[snippetname]]

Sorry, breezer. I changed the Wayfarer snippet call and the first of the 4 Dittos and doing that didn't help. In fact, the Ditto that I changed to uncached no longer worked even when the page was set to 'cachable'.

A very similar issue I saw recently was caused by the phx plugin aggressively removing placeholders. If your snippets output as placeholders and phx is used somewhere in the logic trail before the placeholder is populated maybe that could be a factor.

Also do all the sidebar tv's have content, seems like there is/was an @INHERIT issue with evo I read about a while back. [ed. note: breezer last edited this post 13 years, 5 months ago.]

Quote from: breezer at May 18, 2013, 01:20 AM

A very similar issue I saw recently was caused by the phx plugin aggressively removing placeholders. If your snippets output as placeholders and phx is used somewhere in the logic trail before the placeholder is populated maybe that could be a factor.

There's no 'phx' plugin installed.

Also do all the sidebar tv's have content, seems like there is/was an @INHERIT issue with evo I read about a while back.

4 sidebar TVs and far as I can see all have values.

So far as I am aware, pages that use parameters within the URL, other than simply the page ID (when furl's are not used) are not cacheable

An example, When creating an overview page with pagination, a URL could be:
Not cacheable: mydomain.com/blogoverview?start=10

In the url above you need to experiment with snippet calls

When a document is cacheable, it doesn't mean that a snippet can be called as cacheable in that page

I have experienced a wide range of problems with this phenomenon

An example of my blog overview:
Page / parent doc = not cacheable
Blog post excerpt = cacheable [[]] ditto call
Paginated navigation = not cacheable [!!] split pagination call

Although this is only a small task, it took me ages to get it working correctly - combining cacheable page with non cacheable calls and vice versa

I dont know if its a help but trial and error have proven to work for me

p.s Take a look here:

Snippets and the MODx Cache

The MODx Cache

Document Caching

Parsing uncached snippet not working [ed. note: iusemodx last edited this post 13 years, 5 months ago.]

Although this is only a small task, it took me ages to get it working correctly - combining cacheable page with non cacheable calls and vice versa
I dont know if its a help but trial and error have proven to work for me
p.s Take a look here:

Thanks for your post 'iusemodx'. Your first statement above speaks well to the frustration I'm feeling trying to get cacheable and non-cacheable elements to work together. I will look at the 4 links you've supplied.

Right now I cannot understand what component's at fault. I lose the sidebars managed by Ditto when I make the parent page non-cacheable, but not until a new page is fetched. I don't know how Wayfinder works but it appears as though it's loading the same non-cacheable page but with new content, and yet it's not adding the sidebar content to it. I have no clue whether it expects Ditto to load it, and if so, why Ditto is not doing it. ..... Sigh!

Thanks ... Sam

'iusemodx', I just read through the 4 links you supplied. I think I'm as puzzled now as I was going in.

A primary thing that confuses me is the fact that my original archive page (the one that uses the template which contains the Wayfinder and Ditto calls and which also calls the chunk pg_news_archives) was set to 'uncacheable' in the settings. HOWEVER, I have no control over the page that's displayed by Wayfinder which I believe is the same page but with different content. I can only assume that's the same page that was set to uncacheable and which contains the Ditto calls to the sidebars I need. I have no idea whatever why those sidebars are present when the page is first presented and then the sidebars are dropped when the page is rewritten on subsequent pagination fetches. I just don't get it and don't know what to do about it.

Does what I'm trying to explain make any sense to you?

--- Sam

Just a notice, maybe you can upgrade your evo on a subdomain and see what happens? Or upgrade Ditto?

Quote from: samg at May 20, 2013, 04:16 PM

'iusemodx', I think I'm as puzzled now as I was going in.

@samg
Have PM'd you