Indexes: Converting to JSON and Accessing Metadata

class Products_AllProperties_Result
{
    public ?string $query = null;
    public function getQuery(): ?string
    {
        return $this->query;
    }
    public function setQuery(?string $query): void
    {
        $this->query = $query;
    }
}

class Products_AllProperties extends AbstractIndexCreationTask
{
    public function __construct()
    {
        parent::__construct();

        $this->map = "docs.Products.Select(product => new { " .
            // convert product to JSON and select all properties from it
            "    Query = this.AsJson(product).Select(x => x.Value) " .
            "})";

        // mark 'query' field as analyzed which enables full text search operations
        $this->index("Query", FieldIndexing::search());
    }
}

$results = $session->query(Products_AllProperties_Result::class, Products_AllProperties::class)
        ->whereEquals("Query", "Chocolade")
        ->ofType(Product::class)
        ->toList();

class Products_WithMetadata_Result
{
    public ?DateTime $lastModified = null;

    public function getLastModified(): ?DateTime
    {
        return $this->lastModified;
    }

    public function setLastModified(?DateTime $lastModified): void
    {
        $this->lastModified = $lastModified;
    }
}

class Products_WithMetadata extends AbstractIndexCreationTask
{
    public function __construct()
    {
        parent::__construct();

        $this->map = "docs.Products.Select(product => new { " .
            "    Product = Product, " .
            "    Metadata = this.MetadataFor(product) " .
            "}).Select(this0 => new { " .
            "    LastModified = this0.metadata.Value\<DateTime\>(\"Last-Modified\") " .
            "})";
    }
}

$results = $session
    ->query(Products_WithMetadata_Result::class, Products_WithMetadata::class)
    ->orderByDescending("LastModified")
    ->ofType(Product::class)
    ->toList();