maps: MapLayer slug unicity (#39539)

combo/apps/maps/migrations/0011_map_layer_set_slug.py

@@ -0,0 +1,38 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations
+from django.utils.text import slugify
+
+
+def generate_slug(instance):
+    base_slug = slugify(instance.label)[:45]
+    slug = base_slug
+    i = 1
+    while True:
+        queryset = instance._meta.model.objects.filter(slug=slug).exclude(pk=instance.pk)
+        if not queryset.exists():
+            break
+        slug = '%s-%s' % (base_slug, i)
+        i += 1
+    return slug
+
+
+def set_slug(apps, schema_editor):
+    MapLayer = apps.get_model('maps', 'MapLayer')
+    for layer in MapLayer.objects.all().order_by('-pk'):
+        if not MapLayer.objects.filter(slug=layer.slug).exclude(pk=layer.pk).exists():
+            continue
+        layer.slug = generate_slug(layer)
+        layer.save(update_fields=['slug'])
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('maps', '0010_map_layer_opacity'),
+    ]
+
+    operations = [
+        migrations.RunPython(set_slug, lambda x, y: None),
+    ]

combo/apps/maps/migrations/0012_map_layer_slug_unicity.py

@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('maps', '0011_map_layer_set_slug'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='maplayer',
+            name='slug',
+            field=models.SlugField(unique=True, verbose_name='Identifier'),
+        ),
+    ]

combo/apps/maps/models.py

@@ -102,7 +102,7 @@ class MapLayer(models.Model):
     objects = MapLayerManager()
 
     label = models.CharField(_('Label'), max_length=128)
-    slug = models.SlugField(_('Identifier'))
+    slug = models.SlugField(_('Identifier'), unique=True)
 
     kind = models.CharField(max_length=10, choices=KIND, default='geojson')
 
@@ -138,11 +138,7 @@ class MapLayer(models.Model):
             base_slug = slugify(self.label)[:45]
             slug = base_slug
             i = 1
-            while True:
-                try:
-                    MapLayer.objects.get(slug=slug)
-                except self.DoesNotExist:
-                    break
+            while MapLayer.objects.filter(slug=slug).exists():
                 slug = '%s-%s' % (base_slug, i)
                 i += 1
             self.slug = slug