Add basic feature for "grid totals"

tailbone/templates/master/index.mako

@@ -28,6 +28,19 @@
 
 <%def name="grid_tools()">
 
+  ## grid totals
+  % if master.supports_grid_totals:
+      <b-button v-if="gridTotalsDisplay == null"
+                :disabled="gridTotalsFetching"
+                @click="gridTotalsFetch()">
+        {{ gridTotalsFetching ? "Working, please wait..." : "Show Totals" }}
+      </b-button>
+      <div v-if="gridTotalsDisplay != null"
+           class="control">
+        Totals: {{ gridTotalsDisplay }}
+      </div>
+  % endif
+
   ## download search results
   % if master.results_downloadable and master.has_perm('download_results'):
       <b-button type="is-primary"
@@ -321,6 +334,28 @@
   ${parent.modify_this_page_vars()}
   <script type="text/javascript">
 
+    % if master.supports_grid_totals:
+        ${grid.component_studly}Data.gridTotalsDisplay = null
+        ${grid.component_studly}Data.gridTotalsFetching = false
+
+        ${grid.component_studly}.methods.gridTotalsFetch = function() {
+            this.gridTotalsFetching = true
+
+            let url = '${url(f'{route_prefix}.fetch_grid_totals')}'
+            this.simpleGET(url, {}, response => {
+                this.gridTotalsDisplay = response.data.totals_display
+                this.gridTotalsFetching = false
+            }, response => {
+                this.gridTotalsFetching = false
+            })
+        }
+
+        ${grid.component_studly}.methods.appliedFiltersHook = function() {
+            this.gridTotalsDisplay = null
+            this.gridTotalsFetching = false
+        }
+    % endif
+
     ## maybe auto-redirect to download latest results file
     % if download_results_path:
         ThisPage.methods.downloadResultsRedirect = function() {

tailbone/views/master.py

@@ -107,6 +107,7 @@ class MasterView(View):
     set_deletable = False
     supports_autocomplete = False
     supports_set_enabled_toggle = False
+    supports_grid_totals = False
     populatable = False
     mergeable = False
     merge_handler = None
@@ -1837,6 +1838,9 @@ class MasterView(View):
             self.request.session.flash("Deleted {} {}".format(len(objects), model_title_plural))
         return self.redirect(self.get_index_url())
 
+    def fetch_grid_totals(self):
+        return {'totals_display': "TODO: totals go here"}
+
     def oneoff_import(self, importer, host_object=None):
         """
         Basic helper method, to do a one-off import (or export, depending on
@@ -5198,6 +5202,15 @@ class MasterView(View):
                 config.add_view(cls, attr='download_results_rows', route_name='{}.download_results_rows'.format(route_prefix),
                                 permission='{}.download_results_rows'.format(permission_prefix))
 
+            # fetch total hours
+            if cls.supports_grid_totals:
+                config.add_route(f'{route_prefix}.fetch_grid_totals',
+                                 f'{url_prefix}/fetch-grid-totals')
+                config.add_view(cls, attr='fetch_grid_totals',
+                                route_name=f'{route_prefix}.fetch_grid_totals',
+                                permission=f'{permission_prefix}.list',
+                                renderer='json')
+
         # configure
         if cls.configurable:
             config.add_tailbone_permission(permission_prefix,

tailbone/views/members.py

@@ -406,6 +406,7 @@ class MemberEquityPaymentView(MasterView):
     model_class = model.MemberEquityPayment
     route_prefix = 'member_equity_payments'
     url_prefix = '/member-equity-payments'
+    supports_grid_totals = True
     has_versions = True
 
     grid_columns = [
@@ -470,6 +471,12 @@ class MemberEquityPaymentView(MasterView):
         key = getattr(payment.member, field)
         return key
 
+    def fetch_grid_totals(self):
+        app = self.get_rattail_app()
+        results = self.get_effective_data()
+        total = sum([payment.amount for payment in results])
+        return {'totals_display': app.render_currency(total)}
+
     def configure_form(self, f):
         super().configure_form(f)
         model = self.model