From b8e28c003d099fd4a33985935a9a8672d31d1593 Mon Sep 17 00:00:00 2001
From: Oliver Walters <oliver.henry.walters@gmail.com>
Date: Sun, 14 Apr 2019 00:35:19 +1000
Subject: [PATCH] Provide download link to export BOM file

- Helper function for generating temporary file (in memory) for exporting
---
 InvenTree/InvenTree/helpers.py         | 32 +++++++++++++++++++++
 InvenTree/part/templates/part/bom.html | 10 +++----
 InvenTree/part/views.py                | 39 ++++++++++++++------------
 3 files changed, 57 insertions(+), 24 deletions(-)
 create mode 100644 InvenTree/InvenTree/helpers.py

diff --git a/InvenTree/InvenTree/helpers.py b/InvenTree/InvenTree/helpers.py
new file mode 100644
index 0000000000..84ca1f8881
--- /dev/null
+++ b/InvenTree/InvenTree/helpers.py
@@ -0,0 +1,32 @@
+import io
+import os
+from wsgiref.util import FileWrapper
+from django.http import StreamingHttpResponse, HttpResponse
+
+
+def WrapWithQuotes(text):
+    # TODO - Make this better
+    if not text.startswith('"'):
+        text = '"' + text
+
+    if not text.endswith('"'):
+        text = text + '"'
+
+    return text
+
+
+def DownloadFile(data, filename, content_type='application/text'):
+    """
+    Create a dynamic file for the user to download.
+    @param data is the raw file data
+    """
+
+    filename = WrapWithQuotes(filename)
+
+    wrapper = FileWrapper(io.StringIO(data))
+
+    response = StreamingHttpResponse(wrapper, content_type=content_type)
+    response['Content-Length'] = len(data)
+    response['Content-Disposition'] = 'attachment; filename={f}'.format(f=filename)
+
+    return response
diff --git a/InvenTree/part/templates/part/bom.html b/InvenTree/part/templates/part/bom.html
index 139cc81961..3debd65076 100644
--- a/InvenTree/part/templates/part/bom.html
+++ b/InvenTree/part/templates/part/bom.html
@@ -62,16 +62,14 @@
     });
 
     $("#export-bom").click(function () {
+        /*
         launchModalForm(
                         "{% url 'bom-export' part.id %}",
                         {
-                            /*
-                            reload: true,
-                            data: {
-                                format: 'csv',
-                            }
-                            */
                         });
+        */
+        //TODO - Select format of the data
+        location.href = "{% url 'bom-export' part.id %}";
     });
 
     $("#bom-table").bootstrapTable({
diff --git a/InvenTree/part/views.py b/InvenTree/part/views.py
index 6463352d88..ea1dcc5a52 100644
--- a/InvenTree/part/views.py
+++ b/InvenTree/part/views.py
@@ -21,6 +21,7 @@ from .forms import EditSupplierPartForm
 
 from InvenTree.views import AjaxView, AjaxCreateView, AjaxUpdateView, AjaxDeleteView
 
+from InvenTree.helpers import DownloadFile
 
 class PartIndex(ListView):
     model = Part
@@ -111,34 +112,36 @@ class PartEdit(AjaxUpdateView):
     ajax_form_title = 'Edit Part Properties'
 
 
-class BomExport(AjaxUpdateView):
+class BomExport(AjaxView):
+    # TODO - This should no longer extend an AjaxView!
 
     model = Part
-    form_class = BomExportForm
-    template_name = 'part/bom_export.html'
-    ajax_form_title = 'Export Bill of Materials'
-    ajax_submit_text = 'Export'
-    context_object_name = 'part'
+    #form_class = BomExportForm
+    #template_name = 'part/bom_export.html'
+    #ajax_form_title = 'Export Bill of Materials'
+    #ajax_submit_text = 'Export'
+    #context_object_name = 'part'
 
     def get(self, request, *args, **kwargs):
 
         part = get_object_or_404(Part, pk=self.kwargs['pk'])
-        form = self.form_class(instance=part, data=request.POST, files=request.FILES)
 
-        return self.renderJsonResponse(request, form=form, context={'part': part})
+        export_format = request.GET.get('format', 'csv')
+        
+        # Placeholder to test file export
+        filename = '"' + part.name + '_BOM.' + export_format + '"'
 
-    def post(self, request, *args, **kwargs):
+        filedata = "Part,Quantity,Available\n"
 
-        part = get_object_or_404(Part, pk=self.kwargs['pk'])
-        form = self.form_class(instance=part, data=request.POST, files=request.FILES)
+        for bom_item in part.bom_items.all():
+            filedata += bom_item.sub_part.name
+            filedata += ","
+            filedata += str(bom_item.quantity)
+            filedata += ","
+            filedata += str(bom_item.sub_part.available_stock)
+            filedata += "\n"
 
-        export_format = request.POST.get('format', None)
-
-        if not export_format:
-            # TODO
-            pass
-
-        return self.renderJsonResponse(request, form=form, context={'part': part})
+        return DownloadFile(filedata, filename)
 
     def get_data(self):
         return {