Paginate the list of bills

We display 100 bills on each page.

This uses built-in pagination support from Flask-SQLAlchemy:

  https://flask-sqlalchemy.palletsprojects.com/en/2.x/api/#flask_sqlalchemy.BaseQuery.paginate
  https://flask-sqlalchemy.palletsprojects.com/en/2.x/api/#flask_sqlalchemy.Pagination

ihatemoney/templates/list_bills.html

@@ -97,13 +97,13 @@ <h3 class="modal-title">{{ _('Add a bill') }}</h3>
         </div>
     </div>
 
-    {% if bills.count() > 0 %}
+    {% if bills.total > 0 %}
         <div class="clearfix"></div>
 
         <table id="bill_table" class="col table table-striped table-hover table-responsive-sm">
             <thead><tr><th>{{ _("When?") }}</th><th>{{ _("Who paid?") }}</<th><th>{{ _("For what?") }}</th><th>{{ _("For whom?") }}</th><th>{{ _("How much?") }}</th><th>{{ _("Actions") }}</th></tr></thead>
         <tbody>
-        {% for bill in bills %}
+        {% for bill in bills.items %}
         <tr owers="{{bill.owers|join(',','id')}}" payer="{{bill.payer.id}}">
                 <td>
                     <span data-toggle="tooltip" data-placement="top"
@@ -133,6 +133,22 @@ <h3 class="modal-title">{{ _('Add a bill') }}</h3>
         </tbody>
         </table>
 
+<div class=pagination>
+  {{ _("Page:") }}
+  {%- for page in bills.iter_pages() %}
+  &nbsp;
+  {% if page %}
+  {% if page != bills.page %}
+  <a href="{{ url_for('main.list_bills', page=page) }}">{{ page }}</a>
+  {% else %}
+  <strong>{{ page }}</strong>
+  {% endif %}
+  {% else %}
+  <span class=ellipsis>…</span>
+  {% endif %}
+  {%- endfor %}
+</div>
+
     {% else %}
         <div class="py-3 d-flex justify-content-center empty-bill">
         <div class="card d-inline-flex p-2">

ihatemoney/web.py

@@ -586,7 +586,7 @@ def list_bills():
     if "last_selected_payer" in session:
         bill_form.payer.data = session["last_selected_payer"]
     # Preload the "owers" relationship for all bills
-    bills = g.project.get_bills().options(orm.subqueryload(Bill.owers))
+    bills = g.project.get_bills().options(orm.subqueryload(Bill.owers)).paginate(per_page=100, error_out=True)
 
     return render_template(
         "list_bills.html",