Add CSV export for layer recipes

Add the ability to export the recipe listing for a layer to a CSV file
for importing into external tools. At the moment we include name,
version and license, but there is a parameter that lets you specify the
fields to include in the URL if desired.

Implements [YOCTO #12722].

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>

layerindex/urls_branch.py

@@ -7,7 +7,7 @@
 from django.conf.urls import *
 from django.views.defaults import page_not_found
 from django.core.urlresolvers import reverse_lazy
-from layerindex.views import LayerListView, RecipeSearchView, MachineSearchView, DistroSearchView, ClassSearchView, LayerDetailView, edit_layer_view, delete_layer_view, edit_layernote_view, delete_layernote_view, RedirectParamsView, DuplicatesView, LayerUpdateDetailView
+from layerindex.views import LayerListView, RecipeSearchView, MachineSearchView, DistroSearchView, ClassSearchView, LayerDetailView, edit_layer_view, delete_layer_view, edit_layernote_view, delete_layernote_view, RedirectParamsView, DuplicatesView, LayerUpdateDetailView, layer_export_recipes_csv_view
 
 urlpatterns = [
     url(r'^$', 
@@ -20,6 +20,9 @@ urlpatterns = [
         LayerDetailView.as_view(
             template_name='layerindex/detail.html'),
             name='layer_item'),
+    url(r'^layer/(?P<slug>[-\w]+)/recipes/csv/$',
+        layer_export_recipes_csv_view,
+        name='layer_export_recipes_csv'),
     url(r'^recipes/$',
         RecipeSearchView.as_view(
             template_name='layerindex/recipes.html'),

layerindex/views.py

@@ -1025,3 +1025,25 @@ class StatsView(TemplateView):
                 machine_count=Count('layerbranch__machine', distinct=True),
                 distro_count=Count('layerbranch__distro', distinct=True))
         return context
+
+
+def layer_export_recipes_csv_view(request, branch, slug):
+    import csv
+    layer = get_object_or_404(LayerItem, name=slug)
+    layerbranch = layer.get_layerbranch(branch)
+
+    response = HttpResponse(content_type='text/csv')
+    response['Content-Disposition'] = 'attachment; filename="recipes_%s_%s.csv"' % (layer.name, layerbranch.branch.name)
+
+    fieldlist = request.GET.get('fields', 'pn,pv,license').split(',')
+    recipe_fields = [f.name for f in Recipe._meta.get_fields() if not (f.auto_created and f.is_relation)]
+    for field in fieldlist:
+        if field not in recipe_fields:
+            return HttpResponse('Field %s is invalid' % field)
+
+    writer = csv.writer(response)
+    for recipe in layerbranch.sorted_recipes():
+        values = [getattr(recipe, field) for field in fieldlist]
+        writer.writerow(values)
+
+    return response

templates/layerindex/detail.html

@@ -210,13 +210,13 @@
                         <div class="navbar-inner">
                             <a class="brand pull-left">{{ layeritem.name }} recipes <span class="muted">({{ layerbranch.sorted_recipes.count }})</span></a>
 
-                            <ul class="nav pull-right">
-                                <li>
-                                    <form action="" class="navbar-search pull-right" id="filter-form">
-                                        <input type="text" placeholder="Search recipes" class="search-query" id="filter">
-                                    </form>
-                                </li>
-                            </ul>
+                            <div class="pull-right">
+                                <a href="{% url 'layer_export_recipes_csv' layerbranch.branch.name layerbranch.layer.name %}" class="btn"><i class="icon-file"></i> Export CSV</a>
+
+                                <form action="" class="navbar-search nav-spacer pull-right" id="filter-form">
+                                    <input type="text" placeholder="Search recipes" class="search-query" id="filter">
+                                </form>
+                            </div>
                         </div>
                     </div>