Find Child's Parent's Children

[dps123]

So, here I am, working at the weekend again to get this site done. I'm hoping someone can help me get over this hurdle. I'll try to explain it as best as I can.

I have notes pages using a template 'note'.

Children of those pages are comments, using a template 'comment'.

When a comment is posted, their username is recorded in the field comment_username attached to the comment template.

There is one particularly important commenter. Let's call him John. What I need to do is select new comments where at least one of the comments before that was from John.

I'm trying all kinds of crazy $pages->find things, but going around in circles!

[Robin S]

I'm don't follow exactly what you're wanting to do. For instance, child's parent's children is the same as just children and "new" and "before" is ambiguous. But maybe this works...

$johns_comments = $pages->find("template=comment, comment_username=John");
$comments_after_johns = new PageArray;
foreach($johns_comments as $j_comment) {
    $comments_after_johns->add($j_comment->nextAll);
}

Not tested.

[LostKobrakai]

$johns = $pages->find("template=comment, comment_username=John");

$parents = $johns->explode(function($c){ return $c->parent->id; });

$parents = array_unique($parents);

$repliesToJohn = new PageArray();

foreach($parents as $parent){

$johnsFirstComment = $johns->find("parent=$parent, sort=created");

$afterJohnsFirstComment = $pages->find("template=comment, parent=$parent, created>$johnsFirstComment->created, comment_username!=John");

$repliesToJohn->import($afterJohnsFirstComment);

}

[dps123]

Thanks guys! I hadn't realised just how complicated this was. LostKobrakai - will that method work with page numbers?

[LostKobrakai]

You can make it work with pagination, but it's a bit different to execute.

// This part cannot use pagination, because we need all of john's comments,
// but the whole selector construction is cacheable to minimize load
// invalidate the cache whenever john does post a comment
// optionally you can then also recreate the selector, so the waiting time 
// does hit John and not other users
$johns = $pages->find("template=comment, comment_username=John");
$parents = $johns->explode(function($c){ return $c->parent->id; });
$parents = array_unique($parents);

$commentsSelector = array();
foreach($parents as $parent){
  $johnsFirstComment = $johns->find("parent=$parent, sort=created");
  $commentsSelector[] = "afterjohn=(template=comment, parent=$parent, created>$johnsFirstComment->created, comment_username!=John)";
}

$commentsSelector = implode(', ', $commentsSelector);
// End cacheable

$pages->find($commentsSelector . ', sort=created, limit=10');

[dps123]

Thanks LK, I'll give it a go when I get a mo. The support on this site is unbelievable. You really should charge people for this.

[dps123]

Sorry, one question - what exactly are we doing here with 'afterjohn'?

"afterjohn=(template=comment...

[LostKobrakai]

afterjohn is just a label for all the or-groups, so it's less likely to clash with other or-groups in your selector.

[dps123]

Any idea how I can sort newest to oldest? Changing to -created doesn't seem to work.

$pages->find($commentsSelector . ', sort=-created, limit=10');

[LostKobrakai]

I'm not sure, but this might actually be an issue with or-groups if it's not working. Did you try other fields to sort by?

[dps123]

Yes, there's a 'comment_created_at' field on the comments. I tried that but it didn't affect the results.