Prev() and next() with custom collection

Kirby 2 Solved ✅
1

Hey guys,

as it is written in this post, the functions _next() and _prev() used to do what I am trying to accomplish :smiley: Also it seems I am not the only one – Previous/next article within specific tags?.

So here’s the thing: I want to use next() and prev() functions, together with hasNext()/hasPrev() and so on – but in a custom collection, for example just the images of my folder. But with next() and prev() I always get all files/siblings from the parent collection, without filtering something out. For the moment I hack the code to make those functions not protected anymore, but of course it would be great if there would be a solution directly in the core, without modifying it…

If there’s not an existing feature I can use in this case, I’ll post this as an suggestion, but I wanted to make sure I haven’t failed to see something obvious :wink: Or has anybody another idea how to accomplish this in an easy way?

Thank you!

Edit:
Ha, downside! Those functions are only made for pages, not for files… So more than ever I’m searching for a solution without modifying the core to much :smile:

2

Don’t know if I get you right, but you can do this to show only one (or more) images per page (you can filter images as well in this loop, if you want):

<?php $images = $page->images->paginate(1);
  $pagination = $images->pagination();
  foreach($images as $image) :?>
    <img src="<?= $image->url() ?>">
  <?php endforeach ?>

<?php if($pagination->hasPrevPage()): ?>
<a href="<?= $pagination->prevPageUrl() ?>">
  prev (<?=  $pagination->prevPage() ?>)
</a>
<?php endif ?>

<?php if($pagination->hasNextPage()): ?>
<a href="<?= $pagination->nextPageUrl() ?>">
  next (<?= $pagination->nextPage() ?>)
</a>
<?php endif ?>
3

Hm, no that’s not quite my use case. I have different pages (projects), each with multiple files insight. Sometimes only images, sometimes only videos, sometimes both and documents, … . I open the “file view” by appending a parameter to the page url (file), so if param('file') returns a value (and a file is found), the file view is shown. There I have a simple arrow-navigation for prev/next file – but those should only navigate within the same type of file, so if an image is open, just navigate between the project’s images, and ignore videos and documents. So I need some kind of backwards mechanism – select all files with the same file type like the open one.

My solution for the moment was indeed just copy-pasting the _next/_prev-functions to kirby/core/file.php, and adjusting the first parameter to take only Files instead of Children. It works like a charm now, but unfortunately it’s only possible with modifying the core… is there an obvious reason I’m missing why the _next/_prev-functions are a) only available for a page and not for files, and why they are b) protected and not “officially” supported? I mean, even the usual next and prev function of a page just point to those functions… :wink: Wouldn’t it be the best if they would live inside an Obj?

4

With Kirby 2.3 you can now achieve the same with custom page, file etc. methods, just tested this for a project and it works well.

I have no idea why those methods are protected, maybe because they are only useful if you have a method to keep your original collection by either using an URL parameter, or storing those values in the session, or using cookies …

5

Thanks for keeping this up to date! Awesome service, as always :wink: