README

Adds an extension to make any SilverStripe DataObject sortable.

That is, it does the basic lifting of:

• Adding a Sort field of type DBInt to your object
• Removing the scaffolded field from CMS fields
• Sets the $default_sort of your object to 'Sort'
• Manages setting a Sort value of the maximum + 1 upon first write, within a scope you define

Versioning

Through a bit of bungling, v1.1.1 and v2.1.1 are equal. For clarity, moving forward only 2.x will receive any necessary patches/fixes.

Return types have been added, and a new major version track has been established as v3.x. As such this will require PHP >=7.0, is now the primary track, and will receive any enhancements/features in future.

Requirements

SilverStripe 4 or 5

Installation

composer require fromholdio/silverstripe-sortable

Details

It's all plug-n-play once you apply the extension to your data object - with one exception.

To allow the extension to auto-generate a default value, based on maximum + 1, you need to tell the extension what the scope of the group you're getting that maximum value from is.

So, on the object you are extending/applying Sortable to, you can add a getSortableScope() method. This method should return a DataList on which sortable will run ->max('Sort') on.

In the absence of a getSortableScope() method, as a fallback the extension will get all objects of this type, excluding the current object, and run ->max('Sort') on this list.

See below for example.

Usage example

We are applying Sortable to a Widget data object:

class Widget extends DataObject
{
    // or apply via config.yml
    private static $extensions = [
        Sortable::class
    ];
    
    public function getSortableScope()
    {
        # this is the default behaviour
        return self::get()->exclude('ID', $this->ID);
    }
}

That's it! And it assumes that Widgets will be sorted amongst each other globally.

If Widgets had a one-many relationship with pages, and we want to sort them -per page- then we could do the following instead:

class Widget extends DataObject
{
    private static $has_one = [
        'Page' => \Page::class  // (assuming a has_many on Page for Widgets)
    ];
    
    // or apply via config.yml
    private static $extensions = [
        Sortable::class
    ];
    
    public function getSortableScope()
    {
        return self::get()
            ->filter('PageID', $this->PageID)
            ->exclude('ID', $this->ID);
    }
}

Depending on your data model structures, the ability to pass a scope DataList can be pretty useful. Have fun!