Collection:next / previous with Slugs?

[cbreitigan]

Hi all, I have what might be a specific use-case that I am struggling with and would appreciate some guidance. For context, I am more of a front-end person and have very little knowledge/experience with php. I am also still new to Statamic as I just built the site in question last month after migrating from Jekyll. That all to say, maybe there is an easy solution I am missing but hence the post.

So, I have a collection of entries which need to be in a specific order so that users can cycle through them. Naturally I started with a collection and made it 'orderable' and then I would drag-and-drop entries as needed. But now with over 300 entries moving them around manually is simply not practical. This would become likely impossible as the catalog grows because of the 500 per page limit in the control panel. Therefore I am looking for a new method to create the order I need and retain current functionality. And I cannot sort by date because the dates are all over the place as entries are not made in order they need to be displayed in.

Here is an idea of the collection:
Cardiovascular 1
Cardiovascular 2
Cardiovascular 3
Dermatology 1
Dermatology 2
Dermatology 3
Endocrine 1
Endocrine 2
Endocrine 3
ENT 1
ENT 2
ENT 3
GI 1
GI 2
GI 3
Hematology 1
Hematology 2
Hematology 3
Neurology 1
Neurology 2
Neurology 3
Pharmacology 1
Pharmacology 2
Pharmacology 3
Primary Care 1
Primary Care 2
Primary Care 3

By updating the slugs to be Cardiovascular 01 for example I was able to order the entries in the way that I want and then not have issues as categories hit 20, 30, 40+ entries.

On the home page, I have a section of the site where I am displaying all of the entries but in their respective categories and to get them ordered correctly, without manually ordering the entries in the control panel, I was able to do this:

{{ collection:step2 title:contains="{{ slot }}" sort="slug:asc"}}

{{ title }}

{{ /collection:step2 }}

Now, the problem I am having is on the individual page for each entry. In the previous iteration, when I was using an ordered collection, I was able to very simply use the collection:previous and collection:next tags to move between pages. However, that is not working now because the collection is un-ordered, and as mentioned dates are useless.

What options do I have to regain this functionality? Is there a way to create something similar to move between entries with the collection sorted by Slug?

The current version of the project is live here and on this page you can see the current functionality since the collection is still ordered.

Thank you in advance! Of course I am happy to provide any additional info that would be useful. Hopefully this is easy and just my lack of knowledge/experience.

[jasonvarga]

You should be able to use collection:next and collection:previous but you need to make sure you use the sort parameter to sort appropriately so it knows what the intended next/previous entries should be.

[cbreitigan]

I thought the same thing but I am getting this error, which prompted me to start the thread.

[jasonvarga]

Looking back at the history of this tag, yes I'm absolute wrong about that. I think it was possible way back in v2, before we used queries.

I'm not 100% sure why we force you to use an ordered/dated collection. It was so long ago. 😊 Maybe because sorting by something other than order/date is inconsistent across databases.

For now, you'll need an ordered collection.

This feels weird though. I bet we can make it work.

[cbreitigan]

Thank you for the reply though it is a bummer. Hopefully I can find some kind of work-around or solution since that approach is not sustainable for the scale of this project. There are currently over 350 entries so manual ordering is a pain. That said, is there anyway to dynamically order/re-order a collection? Perhaps some kind of script or tweak somewhere that can determine the order of entries without actually using the 'orderable' feature?

In my main collection yaml file I have sort_dir: asc and sort_by: slug which is controlling the view the way that I want in the control panel. Could there be any kind of order_by option that would do something similar?

Alternatively, might there be any other way to get the list of entries and pass that into the collection:previous tag? Some kind of alias maybe?

[daun]

We wrote a custom tag for a similar feature. It figures out the sort order of the collection and fetches the prev/next entry. It works great for unique values like slug or title.

{{ prev = { sibling:previous } }}
  <a href="{{ url }}">Previous page: {{ title }}</a>
{{ /prev }}

{{ next = { sibling:next } }}
  <a href="{{ url }}">Next page: {{ title }}</a>
{{ /next }}

namespace App\Tags;

use Statamic\Facades\Entry as Entries;
use Statamic\Tags\Tags;

class Sibling extends Tags
{
    public function next()
    {
        return $this->sibling(true);
    }

    public function previous()
    {
        return $this->sibling(false);
    }

    protected function sibling(bool $next = true)
    {
        $entry = Entries::find($this->params->get('current', $this->context->get('id')));
        $collection = $entry->collection();

        $column = $collection->sortField();
        $dir = $collection->sortDirection();
        $dir = $next ? $dir : ($dir === 'asc' ? 'desc' : 'asc');
        $op = $dir === 'asc' ? '>=' : '<';

        return Entries::query()
            ->whereStatus('published')
            ->where('collection', $collection->handle())
            ->where('site', $entry->locale())
            ->where('id', '!=', $entry->id())
            ->where($column, $op, $entry->value($column))
            ->orderBy($column, $dir)
            ->first();
    }
}

[daun]

Interesting. Maybe try ->limit(1)->get()->first() instead of just ->first() in the last line?

[cbreitigan]

I've tried that and some variations but with no luck. Reading through the docs the code you provided should work so this odd. I wonder if it's an issue of scope on my part?

Where in a page would you normally put this? Because I also had to define the collection in the tag before the sibling:previous as I was getting an error before that - "collection clause must come before the status clause". For my context, I am running this in a partial that is part of a layout that the entries in this collection is using.

[daun]

This is directly in an entry's view, in our case views/project.antlers.html. No partial. Maybe you need to make the current entry more specific by passing it into the tag? {{ next = { sibling:next :current="id" } }}. Maybe also check if the value of id matches what you're expecting.

[cbreitigan]

After much trial and error I was able to get this working successfully and as intended! Thank you very much for this. Here is what I ended up with:

->where('collection', $collection->handle()) ->whereStatus('published') ->where('id', '!=', $entry->id()) ->where($column, $op, $entry->$column) ->orderBy($column, $dir) ->first();

[daun]

Nice. The difference being the lack of a locale query and the direct object access instead of an $entry->value() call, am I reading that right?