Shopify Product RSS feed, to be called in /collections/all?view=rss

collection.rss.liquid

{% layout none %}{% comment %}    
/*
 * Shopify Product RSS feed, also needs Cloudflare Workers
 * for Content-Type fix to application/rss+xml, because
 * Shopify only supports text/html
 *
 * Copyright (c) 2018 @fmt github.com/fmt
 * Licensed under the MIT license:
 * http://www.opensource.org/licenses/mit-license.php
 * Based on @freakdesign blog feed gist
 */ 
{% endcomment %}{% capture feedSettings %}

  {% assign feedTitle = 'Product Feed' %}
  {% assign feedDescription = 'Store Products RSS Feed' %}

  {% comment %}
    How many products to show
  {% endcomment %}
  {% assign productCount = 1000 %}

  {% comment %}
    Either to include the product collections
  {% endcomment %}
  {% assign showCollections = true %}

  {% comment %}
    Set image size
  {% endcomment %}
  {% assign imageSize = 'grande' %}

  {% comment %}
    Either to truncate description and content, after how many words
  {% endcomment %}
  {% assign truncateDescription = true %}
  {% assign truncateContent = false %}
  {% assign truncateAfter = 50 %}

  {% comment %}
    Force content to plain text, if HTML breaks syntax
  {% endcomment %}
  {% assign plainText = false %}

  {% comment %}
    Remove CDATA tags, needed if the content already has them
  {% endcomment %}
  {% assign removeCdataTags = true %}

{% endcapture %}<?xml version="1.0" encoding="UTF-8"?>
<rss version="2.0" 
  xmlns:content="http://purl.org/rss/1.0/modules/content/"
  xmlns:wfw="http://wellformedweb.org/CommentAPI/"
  xmlns:dc="http://purl.org/dc/elements/1.1/"
  xmlns:atom="http://www.w3.org/2005/Atom"
  xmlns:sy="http://purl.org/rss/1.0/modules/syndication/"
  xmlns:slash="http://purl.org/rss/1.0/modules/slash/"
  xmlns:media="http://search.yahoo.com/mrss/"
  >
  <channel>
	<title>{{ shop.name }} - {{ feedTitle }}</title>
	<atom:link href="{{ canonical_url }}?view=rss" rel="self" type="application/rss+xml"/>
	<link>{{ canonical_url }}</link>
	<description>{{ feedDescription }}</description>
    <lastBuildDate>{{ collections.all.products.first.created_at | date: "%a, %d %b %Y %H:%M:%S %z" }}</lastBuildDate>
	<language>{{ shop.locale }}</language>
	<sy:updatePeriod>daily</sy:updatePeriod>
	<sy:updateFrequency>1</sy:updateFrequency>

  {% paginate collections.all.products by productCount %}
    {% for product in collections.all.products %}
    <item>
      <title>{{ product.title }}</title>
      <link>{{ shop.url }}{{ product.url }}</link>
      <pubDate>{{ product.created_at | date: "%a, %d %b %Y %H:%M:%S %z" }}</pubDate>
      <dc:creator><![CDATA[{{ product.author | default: shop.name }}]]></dc:creator>
      {% if showCollections %}
        {% assign prodCollections = '' %}
        {% for collection in product.collections %}
          {% assign prodCollections = prodCollections | prepend: collection.title | prepend: ',' %}
        {% endfor %}
        {% assign prodCollectionsLast = prodCollections | remove_last: ',' %}
      <category><![CDATA[
      {{ prodCollectionsLast | remove_first: ',' }}
      ]]></category>
      {% endif %}
      <guid isPermaLink="true">{{ shop.url }}{{ product.url }}</guid>
      <description><![CDATA[
      {% if truncateDescription %}{{ product.content | strip_html | truncatewords: truncateAfter }}
      {% else %}{{ product.content | strip_html }}
      {% endif %}
      ]]></description>
      {% assign productContent = product.content %}{% if removeCdataTags %}{% assign productContent = productContent | remove:'<![CDATA[' | remove:']]' %}{% endif %}
      {% if truncateContent %}<content:encoded>{{ productContent | strip_html | truncate_words:truncateAfter }}</content:encoded>
      {% elsif plainText %}<content:encoded>{{ productContent | strip_html }}</content:encoded>
      {% else %}<content:encoded><![CDATA[{{ productContent | replace:'<br>','<br/>' }}]]></content:encoded>
      {% endif %}
      {% if product.featured_image %}
      <media:content url="https:{{ product.featured_image | img_url: imageSize }}"/>
      {% endif %}
    </item>
    {% endfor %}
  {% endpaginate %}
  </channel>
</rss>

Because Shopify only supports text/html templates, we need to setup @cloudflare Workers (or @aws Lambda@Edge) so that the Content-Type returns as application/rss+xml. This is my take on that, using CF Workers:

addEventListener('fetch', event => {
  if( event.request.url.indexOf('/collections/all?view=rss') === -1 ) {
      return true
  }
  event.passThroughOnException()
  event.respondWith(handleRequest(event.request))
})
async function handleRequest(req) {
    let reqUrl = req.url
    if (reqUrl.indexOf('/collections/all?view=rss') > -1) {
      let res = await fetch(req.url, req)
      let newHdrs = new Headers(res.headers)
      newHdrs.set("Content-Type", "application/rss+xml; charset=UTF-8")
      return new Response(res.body , {
        status: res.status,
        statusText: res.statusText,
        headers: newHdrs
      })
    }
    return fetch(reqUrl, req)
}

Question - It looks like I create a collection.liquid.rss for the rss.

In what area of Shopify do I create the file @cloudflare code? Does it go in the snippet section?

I tried to create this feed for Pinterest. I get this error. "Feed can not be parsed". Any ideas?