#26 Annual conservation report

* adds first try for excel file downloading (WIP)

analysis/views.py

@@ -1,8 +1,7 @@
 from django.contrib import messages
 from django.contrib.auth.decorators import login_required
-from django.core.exceptions import ObjectDoesNotExist
-from django.http import HttpRequest
-from django.shortcuts import render, redirect
+from django.http import HttpRequest, FileResponse
+from django.shortcuts import render, redirect, get_object_or_404
 from django.utils import timezone
 
 from analysis.forms import TimespanReportForm
@@ -55,18 +54,17 @@ def detail_report_view(request: HttpRequest, id: str):
     Returns:
 
     """
+    # Try to resolve the requested office id
+    cons_office = get_object_or_404(
+        KonovaCode,
+        id=id
+    )
+    # Try to resolve the date parameters into Date objects -> redirect if this fails
     try:
-        cons_office = KonovaCode.objects.get(id=id)
-    except (ObjectDoesNotExist, ValueError) as e:
-        messages.error(
-            request,
-            PARAMS_INVALID,
-            extra_tags="danger",
-        )
-        return redirect("analysis:reports")
-    try:
-        date_from = timezone.make_aware(timezone.datetime.fromisoformat(request.GET.get("df", None)))
-        date_to = timezone.make_aware(timezone.datetime.fromisoformat(request.GET.get("dt", None)))
+        df = request.GET.get("df", None)
+        dt = request.GET.get("dt", None)
+        date_from = timezone.make_aware(timezone.datetime.fromisoformat(df))
+        date_to = timezone.make_aware(timezone.datetime.fromisoformat(dt))
     except ValueError:
         messages.error(
             request,
@@ -75,11 +73,24 @@ def detail_report_view(request: HttpRequest, id: str):
         )
         return redirect("analysis:reports")
 
+    # Check whether the html default rendering is requested or an alternative
+    format_param = request.GET.get("format", "html")
     report = TimespanReport(id, date_from, date_to)
-    template = "analysis/reports/detail.html"
-    context = {
-        "office": cons_office,
-        "report": report,
-    }
-    context = BaseContext(request, context).context
-    return render(request, template, context)
+
+    if format_param == "html":
+        template = "analysis/reports/detail.html"
+        context = {
+            "office": cons_office,
+            "report": report,
+        }
+        context = BaseContext(request, context).context
+        return render(request, template, context)
+    elif format_param == "excel":
+        stream = report.to_excel_file()
+        response = FileResponse(
+            filename=stream.name,
+        )
+        response['Content-Disposition'] = f'attachement;"'
+        return response
+    else:
+        raise NotImplementedError