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Strategy

The strategy key defines how html2rss fetches a website’s content.

  • faraday (default): Makes a direct HTTP request. It is fast but does not execute JavaScript.
  • browserless: Renders the website in a headless Chrome browser, which is necessary for JavaScript-heavy sites.

strategy is a top-level config key. Request-specific controls live under request.

To use the browserless strategy, you need a running instance of Browserless.io.

You can run a local Browserless.io instance using Docker:

Terminal window
docker run \
--rm \
-p 3000:3000 \
-e "CONCURRENT=10" \
-e "TOKEN=6R0W53R135510" \
ghcr.io/browserless/chromium

Set the strategy at the top level of your feed configuration and put request controls under request:

strategy: browserless
request:
max_redirects: 5
max_requests: 6
channel:
url: "https://example.com/app"
selectors:
items:
selector: ".article"
title:
selector: "h2"
url:
selector: "a"
extractor: "href"

Use this split consistently:

  • strategy: selects faraday or browserless
  • headers: top-level headers shared by all strategies
  • request.max_redirects: redirect limit for the request session
  • request.max_requests: total request budget for the whole feed build
  • request.browserless.*: Browserless-only options

Example:

strategy: browserless
headers:
User-Agent: "Mozilla/5.0 (compatible; html2rss/1.0)"
request:
max_redirects: 5
max_requests: 6
browserless:
preload:
wait_after_ms: 5000
channel:
url: "https://example.com/app"
selectors:
items:
selector: ".article"
title:
selector: "h2"
url:
selector: "a"
extractor: "href"

Browserless can interact with the page before html2rss captures the final HTML. Configure preload steps under request.browserless.preload.

strategy: browserless
request:
browserless:
preload:
wait_after_ms: 5000
click_selectors:
- selector: ".load-more"
max_clicks: 3
wait_after_ms: 250
scroll_down:
iterations: 5
wait_after_ms: 200
  • wait_after_ms: inserts a fixed wait before or after preload steps
  • click_selectors: clicks matching elements until they disappear or max_clicks is reached
  • scroll_down: scrolls until the page height stops growing or iterations is reached

If preload triggers a real navigation or redirect, html2rss keeps the final document metadata. Relative links and follow-up pagination therefore resolve against the page that was actually rendered after preload completed.

You can also specify the strategy on the command line:

Terminal window
# Set environment variables for your Browserless.io instance
BROWSERLESS_IO_WEBSOCKET_URL="ws://127.0.0.1:3000" \
BROWSERLESS_IO_API_TOKEN="6R0W53R135510" \
html2rss feed my_config.yml --strategy browserless
# Override request budgets at runtime
html2rss feed my_config.yml --max-redirects 5 --max-requests 6
# Or rely on the strategy stored in the YAML config
html2rss feed my_config.yml

For detailed documentation on the Ruby API, see the official YARD documentation.