add package dependencies

src/c3nav/mapdata/migrations/0002_package_depends.py

@@ -0,0 +1,20 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.9 on 2016-09-04 12:20
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('mapdata', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='package',
+            name='depends',
+            field=models.ManyToManyField(to='mapdata.Package'),
+        ),
+    ]

src/c3nav/mapdata/models/package.py

@@ -10,6 +10,7 @@ class Package(models.Model):
     """
     name = models.CharField(_('package identifier'), unique=True, max_length=50,
                             help_text=_('e.g. de.c3nav.33c3.base'))
+    depends = models.ManyToManyField('Package')
 
     bottom = models.DecimalField(_('bottom coordinate'), null=True, max_digits=6, decimal_places=2)
     left = models.DecimalField(_('left coordinate'), null=True, max_digits=6, decimal_places=2)
@@ -28,6 +29,11 @@ class Package(models.Model):
             raise ValueError('pkg.json: missing package name.')
         kwargs['name'] = data['name']
 
+        depends = data.get('depends', [])
+        if not isinstance(depends, list):
+            raise TypeError('pkg.json: depends has to be a list')
+        kwargs['depends'] = depends
+
         if 'bounds' in data:
             bounds = data['bounds']
             if len(bounds) != 2 or len(bounds[0]) != 2 or len(bounds[1]) != 2:
@@ -49,5 +55,7 @@ class Package(models.Model):
         data['name'] = self.name
         if self.bottom is not None:
             data['bounds'] = ((float(self.bottom), float(self.left)), (float(self.top), float(self.right)))
+        if self.depends.exists():
+            data['depends'] = tuple(package.name for package in self.depends.all().order_by('name'))
 
         return data

src/c3nav/mapdata/packageio/utils.py

@@ -39,7 +39,15 @@ class ObjectCollection:
 
     def apply_to_db(self):
         for name, package in tuple(self.packages.items()):
+            for depname in package['depends']:
+                if depname not in self.packages:
+                    raise CommandError('Missing dependency: %s' % depname)
+
+        for name, package in tuple(self.packages.items()):
+            package = package.copy()
+            orig_deps = package.pop('depends', [])
             package, created = Package.objects.update_or_create(name=name, defaults=package)
+            package.orig_deps = orig_deps
             self.packages[name] = package
             if created:
                 print('- Created package: '+name)
@@ -70,6 +78,20 @@ class ObjectCollection:
             print('- Deleted package: '+package.name)
             package.delete()
 
+        for name, package in tuple(self.packages.items()):
+            has_deps = []
+            for dependency in tuple(package.depends.all()):
+                if dependency.name not in package.orig_deps:
+                    package.depends.remove(dependency)
+                    print('- Removed dependency: '+dependency.name)
+                else:
+                    has_deps.append(dependency.name)
+
+            for depname in package.orig_deps:
+                if depname not in has_deps:
+                    package.depends.add(self.packages[depname])
+                    print('- Added dependency: '+depname)
+
 
 def _preencode(data, magic_marker):
     if isinstance(data, dict):