Update product description when out of stock, with Mechanic.

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Update product description when out of stock

This task prepends an HTML message to the beginning of the product description, for each product that goes out of stock, and then restores the original product description when the product is back in stock. Optionally, you may choose to append the HTML message to the end of the product description, instead of prepending it to the beginning.

Runs when an inventory level is updated and when a user triggers the task. Configuration includes only modify products with this tag, add this html to product description, and add the html to end of product description instead of beginning.

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Documentation

This task prepends an HTML message to the beginning of the product description, for each product that goes out of stock, and then restores the original product description when the product is back in stock. Optionally, you may choose to append the HTML message to the end of the product description, instead of prepending it to the beginning.

The task runs when inventory levels change, or may be run manually on demand. Manual runs will ignore products that do not have inventory tracking enabled.

Developer details

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That’s why we make it easy to configure automation without code, why we make it easy to tweak the underlying code once tasks are installed, and why we publish it all here for everyone to learn from.

Open source
View on GitHub to contribute to this task
Events
when an inventory level is updated (shopify/inventory_levels/update)
when a user triggers the task (mechanic/user/trigger)
Options
only modify products with this tag, add this html to product description (multiline, required), add the html to end of product description instead of beginning (boolean)
Script
{% comment %}
  Options order:

  {{ options.only_modify_products_with_this_tag }}
  {{ options.add_this_html_to_product_description__multiline_required }}
  {{ options.add_the_html_to_end_of_product_description_instead_of_beginning__boolean }}
{% endcomment %}

{% assign products_to_check = array %}

{% if event.topic == "shopify/inventory_levels/update" %}
  {% capture query %}
    query {
      inventoryLevel(
        id: {{ inventory_level.admin_graphql_api_id | json }}
      ) {
        item {
          variant {
            product {
              id
              descriptionHtml
              tags
              totalInventory
            }
          }
        }
      }
    }
  {% endcapture %}

  {% assign result = query | shopify %}

  {% if event.preview %}
    {% capture result_json %}
      {
        "data": {
          "inventoryLevel": {
            "item": {
              "variant": {
                "product": {
                  "id": "gid://shopify/Product/1234567890",
                  "descriptionHtml": "<p>The best widget on the market!</p>",
                  "tags": {{ options.only_modify_products_with_this_tag | json }},
                  "totalInventory": 0
                }
              }
            }
          }
        }
      }
    {% endcapture %}

    {% assign result = result_json | parse_json %}
  {% endif %}

  {% assign product = result.data.inventoryLevel.item.variant.product %}

  {% if options.only_modify_products_with_this_tag != blank %}
    {% if product.tags contains options.only_modify_products_with_this_tag %}
      {% assign products_to_check[0] = product %}
    {% else %}
      {% log message: "This product does not have the tag being filtered by; skipping", tag_required: options.only_modify_products_with_this_tag, product_tags: product.tags %}
    {% endif %}
  {% else %}
    {% assign products_to_check[0] = product %}
  {% endif %}

{% elsif event.topic == "mechanic/user/trigger" %}
  {% assign cursor = nil %}
  {% assign products_query = nil %}

  {% if options.only_modify_products_with_this_tag != blank %}
    {% assign products_query = options.only_modify_products_with_this_tag | json | prepend: "tag:" %}
  {% endif %}

  {% for n in (0..100) %}
    {% capture query %}
      query {
        products(
          first: 250
          after: {{ cursor | json }}
          query: {{ products_query | json }}
        ) {
          pageInfo {
            hasNextPage
          }
          edges {
            cursor
            node {
              id
              descriptionHtml
              tracksInventory
              totalInventory
            }
          }
        }
      }
    {% endcapture %}

    {% assign result = query | shopify %}

    {% if event.preview %}
      {% capture result_json %}
        {
          "data": {
            "products": {
              "edges": [
                {
                  "node": {
                    "id": "gid://shopify/Product/1234567890",
                    "descriptionHtml": "<p>The best widget on the market!</p>",
                    "tracksInventory": true,
                    "totalInventory": 0
                  }
                }
              ]
            }
          }
        }
      {% endcapture %}

      {% assign result = result_json | parse_json %}
    {% endif %}

    {% assign products = result.data.products.edges | map: "node" | where: "tracksInventory" %}
    {% assign products_to_check = products_to_check | concat: products %}

    {% if result.data.products.pageInfo.hasNextPage %}
      {% assign cursor = result.data.products.edges.last.cursor %}
    {% else %}
      {% break %}
    {% endif %}
  {% endfor %}
{% endif %}

{% if products_to_check != blank %}
  {% for product in products_to_check %}
    {% assign cache_key = product.id | append: "__description_to_restore" %}
    {% assign cached_description_html = cache[cache_key] %}

    {% if product.totalInventory > 0 %}
      {% if cached_description_html != blank %}
        {% action "shopify" %}
          mutation {
            productUpdate(
              input: {
                id: {{ product.id | json }}
                descriptionHtml: {{ cached_description_html | json }}
              }
            ) {
              userErrors {
                field
                message
              }
            }
          }
        {% endaction %}

        {% action "cache", "del", cache_key %}
      {% endif %}

    {% else %}
      {% unless product.descriptionHtml contains options.add_this_html_to_product_description__multiline_required %}
        {% if options.add_the_html_to_end_of_product_description_instead_of_beginning__boolean %}
          {% assign updated_description_html = product.descriptionHtml | append: options.add_this_html_to_product_description__multiline_required %}
        {% else %}
          {% assign updated_description_html = product.descriptionHtml | prepend: options.add_this_html_to_product_description__multiline_required %}
        {% endif %}

        {% action "shopify" %}
          mutation {
            productUpdate(
              input: {
                id: {{ product.id | json }}
                descriptionHtml: {{ updated_description_html | json }}
              }
            ) {
              userErrors {
                field
                message
              }
            }
          }
        {% endaction %}

        {% action "cache", "set", cache_key, product.descriptionHtml %}
      {% endunless %}
    {% endif %}
  {% endfor %}
{% endif %}
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