2 random dittos on the same page repeat content

I have 2 ditto calls in the same template which pull a single item at random from the same parent. I understand that sometimes they will duplicate, but it’s always duplicating. Is this a bug, or expected behaviour?

Thanks,
Krys

What do your Ditto calls look like? Do they have the &id parameter set?
KP

here it is:



Every time I refresh the page, I get different quotes, but always duplicated.

Since they both use the same startId (you really should use &parents instead) they’ll both be applying the same algorithm for selecting a random entry from the same array of results. Try changing the sort direction on one of them, then they’ll be starting from different array items. There is a reason why most of the programming algorithms for randomization are called "pseudo-random"!

As an explicit way of distinguishing one call from the other, you could give each call an &id parameter, e.g &id=`first` and &id=`second`. This will encourage Ditto to create a separate results resource for each.

I tried a little experiment with a simplified version of your Ditto call, and found that in fact any difference, even adding a dummy parameter like &fred to one of them, produced a difference in results. But &id would be the orthodox way.
KP

if you want different outputs from multiple snippet-calls you need different parameters, that can also be dummy-parameters.

why?
see function evalSnippets in /manager/includes/document.parser.class.inc.php this line:

And, of course, though you now have two Ditto calls, each with their own results, there’s no guarantee that the two "random" results won’t be the same...

So what you could do with is a snippet that generates a list of valid document IDs in random order and feeds two of them to the Ditto calls using the &documents parameter instead of &startID or &parents, (e.g. by getting them into an array and using PHP’s array_rand or shuffle functions to set placeholders).
KP

Thanks for all the help - those changes fixed it!

Writing the suggested snippet is sadly beyond my skillset...