Product Import from Google Merchant Feed

Implementing Product Import from Google Merchant Feed

Google Merchant Feed (GMF) is XML format based on Atom/RSS with g: namespace fields that manufacturers prepare for Google Shopping. For store, import from this format provides access to well-structured data with mandatory id, title, description, price and availability fields.

Feed Structure

<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" xmlns:g="http://base.google.com/ns/1.0">
  <channel>
    <title>Supplier Product Feed</title>
    <item>
      <g:id>SKU-12345</g:id>
      <g:title>Wireless Headphones Example Pro</g:title>
      <g:description>Headphones with noise cancellation, 30 hours battery</g:description>
      <g:price>4990 RUB</g:price>
      <g:sale_price>3990 RUB</g:sale_price>
      <g:availability>in stock</g:availability>
      <g:brand>Example</g:brand>
      <g:gtin>0012345678901</g:gtin>
      <g:color>Black</g:color>
    </item>
  </channel>
</rss>

Parser with Namespace Support

Key feature — all product fields in g: namespace. SimpleXML requires explicit namespace handling:

class GoogleMerchantFeedParser
{
    private const G_NS = 'http://base.google.com/ns/1.0';

    public function parse(string $filePath): iterable
    {
        $reader = new \XMLReader();
        $reader->open($filePath);

        while ($reader->read()) {
            if ($reader->nodeType === \XMLReader::ELEMENT && $reader->name === 'item') {
                $node = new \SimpleXMLElement($reader->readOuterXml());
                $g = $node->children(self::G_NS);
                yield $this->parseItem($g);
            }
        }
        $reader->close();
    }

    private function parseItem(\SimpleXMLElement $g): array
    {
        [$price, $currency] = $this->parsePrice((string) $g->price);

        return [
            'sku'         => (string) $g->id,
            'name'        => (string) $g->title,
            'description' => (string) $g->description,
            'price'       => $price,
            'currency'    => $currency,
            'availability'=> $this->parseAvailability((string) $g->availability),
            'brand'       => (string) $g->brand,
            'gtin'        => (string) $g->gtin,
            'color'       => (string) $g->color,
            'images'      => array_filter([(string) $g->image_link]),
        ];
    }

    private function parsePrice(string $raw): array
    {
        // "4990 RUB" → [4990.0, 'RUB']
        if (preg_match('/^([\d.,]+)\s+([A-Z]{3})$/', trim($raw), $m)) {
            return [(float) str_replace(',', '.', $m[1]), $m[2]];
        }
        return [(float) $raw, 'RUB'];
    }

    private function parseAvailability(string $raw): string
    {
        return match (strtolower(trim($raw))) {
            'in stock'      => 'in_stock',
            'out of stock'  => 'out_of_stock',
            'preorder'      => 'preorder',
            default         => 'unknown',
        };
    }
}

GTIN-based Deduplication

GTIN (EAN-13, UPC, ISBN) — global identifier for exact product matching:

$product = Product::where('gtin', $offer['gtin'])
    ->orWhere('sku', $offer['sku'])
    ->first();

Priority: GTIN > SKU > MPN.

Compressed Feeds (.gz)

Google recommends compressing large feeds. Auto-detect:

private function openFeed(string $url): string
{
    if (str_ends_with(parse_url($url, PHP_URL_PATH), '.gz')) {
        $gz = gzopen($url, 'rb');
        $fp = fopen($tmpFile, 'wb');
        while (!gzeof($gz)) fwrite($fp, gzread($gz, 8192));
        gzclose($gz);
        fclose($fp);
    } else {
        copy($url, $tmpFile);
    }
    return $tmpFile;
}

Implementation Timeline

• Parser with namespace, basic fields, availability, price with currency — 1–2 days
• Variable products via item_group_id, Google category mapping — +1–2 days
• GTIN-deduplication, compressed feeds, image download — +1 day