refactor: Jinja experiment for AffiliateLinks template

openlibrary/macros/AffiliateLinks.html.jinja

@@ -0,0 +1,33 @@
+{% macro affiliate_link(store) %}
+  <li class="prices-{{ store.key }}">
+      <a href="{{ store.link }}"
+         title="{{ _('Look for this edition for sale at %(store)s', store=store.name) }}"
+         data-ol-link-track="BuyLink|{{ store.analytics_key }}"
+         target="_blank" rel="noopener noreferrer">{{ store.name }}</a>
+      {% if store.price %}
+        <br>
+        <span name="price">{{ store.price }}{{ store.price_note }}</span>
+      {% endif %}
+  </li>
+{% endmacro %}
+
+<span class="affiliate-links-section">
+  <ul class="buy-options-table">
+      {% for store in primary_stores %}
+        {{ affiliate_link(store) | safe }}
+      {% endfor %}
+      {% if more_stores %}
+        <li class="more">
+          <details>
+            <summary>{{ _('More') }}</summary>
+            <ul>
+              {% for store in more_stores %}
+                {{ affiliate_link(store) | safe }}
+              {% endfor %}
+            </ul>
+          </details>
+        </li>
+      {% endif %}
+  </ul>
+  <small>{{ _('When you buy books using these links the Internet Archive may earn a <a class="nostyle" href="/help/faq/about#selling">small commission</a>.') | safe }}</small>
+</span>

openlibrary/plugins/openlibrary/partials.py

@@ -1,9 +1,15 @@
+import logging
+import os
+import re
+import time as _time
 from dataclasses import dataclass
 from hashlib import md5
+from pathlib import Path
 from typing import Literal, NotRequired, TypedDict
 from urllib.parse import parse_qs, quote, quote_plus
 
 import web
+from jinja2 import Environment, FileSystemLoader
 from pydantic import BaseModel
 
 from infogami.utils.view import public, render_template
@@ -19,7 +25,6 @@
     get_betterworldbooks_metadata,
 )
 from openlibrary.i18n import gettext as _
-from openlibrary.plugins.openlibrary.code import is_bot
 from openlibrary.plugins.openlibrary.lists import get_lists_async, get_user_lists
 from openlibrary.plugins.upstream.utils import render_macro
 from openlibrary.plugins.upstream.yearly_reading_goals import get_reading_goals
@@ -292,6 +297,35 @@ def build_more_stores(ctx: AffiliateStoreBuildContext) -> list[AffiliateStore]:
     ]
 
 
+_JINJA_ENV = Environment(
+    loader=FileSystemLoader(Path(__file__).resolve().parent.parent.parent / "macros"),
+    autoescape=True,
+)
+_JINJA_ENV.globals["_"] = _
+
+_EXPERIMENT_LOGGER = logging.getLogger("openlibrary.jinja_experiment")
+_JINJA_EXPERIMENT_ENABLED = os.getenv("OL_JINJA_EXPERIMENT") == "1"
+
+
+def _normalize_html(html: str) -> str:
+    """Collapse all non-semantic whitespace in HTML for comparison between engines."""
+    html = re.sub(r">\s+<", "><", html)
+    html = re.sub(r"\s{2,}", " ", html)
+    return html.strip()
+
+
+def _render_affiliate_links_jinja(
+    primary_stores: list[AffiliateStore],
+    more_stores: list[AffiliateStore],
+) -> str:
+    """Render affiliate links using Jinja2 for experiment comparison."""
+    template = _JINJA_ENV.get_template("AffiliateLinks.html.jinja")
+    return template.render(
+        primary_stores=primary_stores,
+        more_stores=more_stores,
+    )
+
+
 class AffiliateLinksPartial:
     """Handler for affiliate links"""
 
@@ -302,6 +336,8 @@ async def generate_async(
         asin: str | None,
         prices: bool,
     ) -> dict:
+        from openlibrary.plugins.openlibrary.code import is_bot
+
         bwb_metadata = None
         amz_metadata = None
         should_fetch_prices = not is_bot() and prices
@@ -317,8 +353,34 @@ async def generate_async(
 
         primary_stores = build_primary_stores(ctx)
         more_stores = build_more_stores(ctx)
+
+        t0 = _time.perf_counter()
         macro = web.template.Template.globals["macros"].AffiliateLinks(primary_stores, more_stores)
-        return {"partials": str(macro)}
+        templetor_html = str(macro)
+        t1 = _time.perf_counter()
+
+        if _JINJA_EXPERIMENT_ENABLED:
+            t2 = _time.perf_counter()
+            try:
+                jinja2_html = _render_affiliate_links_jinja(primary_stores, more_stores)
+                t3 = _time.perf_counter()
+                match = _normalize_html(templetor_html) == _normalize_html(jinja2_html)
+                _EXPERIMENT_LOGGER.info(
+                    "Jinja2 experiment | match=%s templetor_ms=%.2f jinja2_ms=%.2f | title=%s isbn=%s",
+                    match,
+                    (t1 - t0) * 1000,
+                    (t3 - t2) * 1000,
+                    title,
+                    isbn,
+                )
+            except Exception:
+                _EXPERIMENT_LOGGER.exception(
+                    "Jinja2 experiment failed | title=%s isbn=%s",
+                    title,
+                    isbn,
+                )
+
+        return {"partials": templetor_html}
 
 
 class SearchFacetsPartial: