Fetch products from Shopify and create or update metafields with key value of each product with Shopify api's.

Sometime, it becomes essentials to add a customized metafield in product so,we can add some functionality with the help of these metafields.
In this blog, we will fetch products from a store of shopify and create our customized metafield in which we will add pdf file url for each product.

 ############ Required Dependencies ##############


    require 'rubygems'

    require 'shopify_api'



    ############ Shopify Credentials ################


    API_KEY = '846bef1--------------------------'

    PASSWORD = '2e0eed--------------------------'

    SHOPNAME = 'store_name_of_shopify-----------'

    shop_url = "https://#{API_KEY}:#{PASSWORD}@#{SHOPNAME}.myshopify.com/admin"


    ##### Fetch Products and create metafields ######   

    begin

      ShopifyAPI::Base.site = shop_url

      products = ShopifyAPI::Product.all

      products.each do |product|

        metafield = ShopifyAPI::Metafield.new(key:'pdf_url_s3',

                                          namespace: "headerlabs",

                                          value: 'http://docs.aws.amazon.com/AmazonS3/latest/dev/s3-dg.pdf',

                                          value_type: "string")

        product.add_metafield(metafield)

      end

    rescue => e

      puts e.inspect

    end

Now, you can access these metafields in template of product in shopify liquid file

    {% assign headerlabs = product.metafields.headerlabs %}

    {% assign key = 'pdf_url_s3' %}

    <a href={{ headerlabs.pdf_url_s3}} target="_blank" >