Getting started

Until now we've only taken a look at transforming PHP classes to TypeScript, but what if you want to transform something else? This is where the TransformedProvider comes into play, it is a class that provides TypeScript types and other structures. The transformers we've seen before are actually bundled in a default TransformerProvider provided by the package.

A TransformedProvider implements the TransformedProvider interface:

namespace Spatie\TypeScriptTransformer\TransformedProviders;

interface TransformedProvider
{
    /**
     * @return array<Transformed>
     */
    public function provide(): array;
}

The provide method is called when the TypeScript transformer is executed, it should return Transformed objects.

We could for example add a generic type which transforms Laravel collections:

class AddLaravelCollectionProvider implements TransformedProvider
{
    public function provide(): array
    {
        $type = new Transformed(
            typeScriptNode: new TypeScriptAlias(
                new TypeScriptGeneric(
                    new TypeScriptIdentifier('Collection'),
                    [new TypeScriptIdentifier('T')],
                ),
                new TypeScriptGeneric(
                    new TypeScriptIdentifier('Array'),
                    [new TypeScriptIdentifier('T')],
                ),
            ),
            reference: new ClassStringReference(Collection::class),
            location: ['Illuminate', 'Support']
        ));

        return [$type];
    }
}

When we register the provider as such in the configuration:

$config->provider(new AddLaravelCollectionProvider());

Our transformed TypeScript will have the following type:

namespace Illuminate.Support {
    export type Collection<T> = Array<T>;
}

When referencing a Laravel collection in one of our PHP classes like this:

class Data
{
    /** @var Collection<string>  */
    public Collection $collection;
}

The transformed TypeScript will look like this:

export type Data = {
    collection: Illuminate.Support.Collection<string>;
}