Add basic pagination to search results

The "deep paging problem" imposes some limit, which currently is a
hardcoded default value, `deep_page_limit=2000` in `do_search`.

Elasticsearch can be configured, too:

> Note that from + size can not be more than the index.max_result_window
index setting, which defaults to 10,000.

-- https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-body.html#request-body-search-from-size

1 files changed, 22 insertions, 2 deletions

diff --git a/python/fatcat_web/templates/release_search.html b/python/fatcat_web/templates/release_search.html
index 7d6b0443..359038dc 100644
--- a/python/fatcat_web/templates/release_search.html
+++ b/python/fatcat_web/templates/release_search.html
@@ -36,8 +36,28 @@
 
 {% if found %}
 {% if found.results %}
-  <i>Showing top {{ found.count_returned }} out of {{ found.count_found }} results for: <code>{{ found.query.q }}</code></i>
-{% for paper in found.results %}
+  <i>Showing
+    {% if found.offset == 0 %}
+      first
+    {% else %}
+      results {{ found.offset }} &mdash;
+    {% endif %}
+    {{ found.offset + found.count_returned }} out of {{ found.count_found }} results for: <code>{{ found.query.q }}</code></i>
+
+    <br>
+    {% if found.offset > 0 %}
+        {% if found.offset - found.limit < 0 %}
+          <a href="{{ url_for('release_search', q=query, offset=0) }}">Prev</a>
+        {% else %}
+          <a href="{{ url_for('release_search', q=query, offset=found.offset - found.limit) }}">Prev</a>
+        {% endif %}
+    {% endif %}
+
+    {% if found.offset + found.limit < found.count_found and found.offset + found.limit < found.deep_page_limit %}
+      <a href="{{ url_for('release_search', q=query, offset=found.offset + found.limit) }}">Next</a>
+    {% endif %}
+
+  {% for paper in found.results %}
   {{ entity_macros.release_search_result_row(paper) }}
 {% endfor %}
 {% if found.results|length > 8 %}