version: "1.0.0" name: developing-new-attachables description: Turn Eloquent models into rich text content attachments (e.g., user mentions, embedded resources) using the AttachableContract and Attachable trait.

Developing New Attachables

When to use this skill

Use this skill when turning an Eloquent model into a content attachment for rich text editors (e.g., user mentions, embedded resources), or when creating custom non-model attachables (e.g., OpenGraph embeds).

Making a Model Attachable

1. Implement the Contract and Use the Trait

The model must implement AttachableContract and use the Attachable trait:

@verbatim

use Tonysm\RichTextLaravel\Attachables\AttachableContract;
use Tonysm\RichTextLaravel\Attachables\Attachable;
 
class User extends Model implements AttachableContract
{
    use Attachable;
 
    // ...
}

@endverbatim

2. Implement the richTextRender() Method

This is the only required method. It returns the HTML used when displaying the attachment outside the editor:

@verbatim

public function richTextRender(array $options = []): string
{
    return view('mentions.partials.user', [
        'user' => $this,
    ])->render();
}

@endverbatim

The $options array may contain an in_gallery boolean when the attachment is rendered inside a gallery.

3. Create the Blade Partial

Create a Blade view that renders the attachment's HTML. This is the content end users will see:

@verbatim

{{-- resources/views/mentions/partials/user.blade.php --}}
<span class="mention">
    {{ $user->name }}
</span>

@endverbatim

4. Optional: Plain Text and Markdown Representations

For plain text export (toPlainText()), implement:

@verbatim

public function richTextAsPlainText(?string $caption = null): string
{
    return $this->name;
}

@endverbatim

For Markdown export (toMarkdown()), implement:

@verbatim

public function richTextAsMarkdown(?string $caption = null): string
{
    return $caption ?: $this->name;
}

@endverbatim

If these methods are not implemented and no caption is stored, the attachment won't appear in the respective output.

5. Optional: Override Default Trait Methods

The Attachable trait provides sensible defaults for these methods, but you can override them:

• richTextContentType(): string — defaults to 'application/octet-stream'
• richTextFilename(): ?string — defaults to null
• richTextFilesize(): ?int — defaults to null
• richTextPreviewable(): bool — defaults to false
• richTextMetadata(?string $key = null): mixed — defaults to null

6. Using a Separate Trait for Organization

For better organization, extract the attachable behavior into its own trait:

@verbatim

// app/Models/User/Mentionee.php
namespace App\Models\User;
 
use Tonysm\RichTextLaravel\Attachables\Attachable;
 
trait Mentionee
{
    use Attachable;
 
    public function richTextRender(array $options = []): string
    {
        return view('mentions.partials.user', ['user' => $this])->render();
    }
 
    public function richTextAsPlainText(?string $caption = null): string
    {
        return e($this->name);
    }
 
    public function richTextAsMarkdown(?string $caption = null): string
    {
        return $caption ?: e($this->name);
    }
}

@endverbatim

Then use it on the model:

@verbatim

class User extends Model implements AttachableContract
{
    use User\Mentionee;
}

@endverbatim

Custom Attachables Without SGIDs

For attachments that don't need a database record (e.g., OpenGraph embeds), implement AttachableContract directly on a plain class and register a custom resolver:

@verbatim

use Tonysm\RichTextLaravel\RichTextLaravel;
 
// In AppServiceProvider::boot()
RichTextLaravel::withCustomAttachables(function (DOMElement $node) {
    if ($attachable = OpengraphEmbed::fromNode($node)) {
        return $attachable;
    }
});

@endverbatim

The class must implement toRichTextAttributes(), equalsToAttachable(), and richTextRender(). Use a content-type attribute on the node to identify your custom attachment type:

@verbatim

class OpengraphEmbed implements AttachableContract
{
    const CONTENT_TYPE = 'application/vnd.rich-text-laravel.opengraph-embed';
 
    public static function fromNode(DOMElement $node): ?self
    {
        if ($node->getAttribute('content-type') === static::CONTENT_TYPE) {
            return new self(/* attributes from node */);
        }
 
        return null;
    }
 
    public function richTextRender(array $options = []): string
    {
        return view('attachables.opengraph-embed', ['attachable' => $this])->render();
    }
 
    public function toRichTextAttributes(array $attributes): array
    {
        return [
            'content_type' => static::CONTENT_TYPE,
            'previewable' => true,
            // ... your custom attributes
        ];
    }
 
    public function equalsToAttachable(AttachableContract $attachable): bool
    {
        return $this->richTextRender() === $attachable->richTextRender();
    }
}

@endverbatim

How SGIDs Work

The Attachable trait automatically generates a Signed Global ID (SGID) for the model via richTextSgid(). This SGID is stored in the <rich-text-attachment sgid="..."> tag in the canonical HTML. When content is rendered, the AttachableFactory resolves the SGID back to the original model. SGIDs are signed using your APP_KEY and never expire for rich text attachments.

Frontend: Creating Attachments in the Editor

On the frontend, create attachments in the editor when a user selects an attachable. The key data needed from your API endpoint is:

• sgid — the model's Signed Global ID
• content — the HTML to display inside the editor

For Trix, create a new Trix.Attachment({ sgid, content, contentType: '...' }) and insert it. For Lexxy or custom editors, the mechanism differs but the concept is the same: embed an attachment node with the sgid attribute.

Retrieving Attachables from Content

After saving, extract all attachables of a specific type:

@verbatim

use Tonysm\RichTextLaravel\Attachment;
 
$post->body->attachments()
    ->filter(fn (Attachment $attachment) => $attachment->attachable instanceof User)
    ->map(fn (Attachment $attachment) => $attachment->attachable)
    ->unique();

@endverbatim