add model mixin from edc-base

README.rst

@@ -3,7 +3,50 @@
 edc-list-data
 -------------
 
-Populate list data and other static model data on startup.
+Populate list data and other static model data on ``Django`` startup.
+
+To install add ``edc_list_data.apps.AppConfig`` to your `INSTALLED_APPS`, then create a ``list_data.py`` in the root of your app.
+
+Most commonly used to populate M2M data known here as ``list_data``. M2M field models should use the ``ListModelMixin``.
+
+For example:
+
+.. code-block:: python
+
+	class Antibiotic(ListModelMixin, BaseUuidModel):
+
+	    class Meta(ListModelMixin.Meta):
+	        pass
+
+
+An example ``list_data.py``:
+
+
+.. code-block:: python
+	
+	from edc_constants.constants import OTHER
+	from edc_list_data import PreloadData
+
+	list_data = {
+	    'my_lists_app.antibiotic': [
+	        ('flucloxacillin', 'Flucloxacillin'),
+	        ('gentamicin', 'Gentamicin'),
+	        ('ceftriaxone', 'Ceftriaxone'),
+	        ('amoxicillin_ampicillin', 'Amoxicillin/Ampicillin'),
+	        ('doxycycline', 'Doxycycline'),
+	        ('erythromycin', 'Erythromycin'),
+	        ('ciprofloxacin', 'Ciprofloxacin'),
+	        (OTHER, 'Other, specify')
+	    ],
+	}
+
+	preload_data = PreloadData(list_data=list_data)
+
+
+``PreloadData`` will persist the list data in model ``Antibiotic`` and maintain the order in which the list items are declared.
+
+See also call to ``site_list_data.autodiscover`` called in ``edc_list_data.apps.AppConfig``.
+
 
 
 .. |pypi| image:: https://img.shields.io/pypi/v/edc-list-data.svg

edc_list_data/model_mixins.py

@@ -0,0 +1,69 @@
+from django.db import models
+
+
+class ListModelManager(models.Manager):
+
+    def get_by_natural_key(self, short_name):
+        return self.get(short_name=short_name)
+
+
+class ListModelMixin(models.Model):
+
+    """Mixin for list data used in dropdown and radio widgets having
+    display value and store value pairs.
+    """
+
+    name = models.CharField(
+        verbose_name='Name',
+        max_length=250,
+        unique=True,
+        db_index=True,
+        help_text='(suggest 40 characters max.)',
+    )
+
+    # FIXME: this should be a short string, e.g. 15-25 chars!
+    short_name = models.CharField(
+        verbose_name="Stored value",
+        max_length=250,
+        unique=True,
+        db_index=True,
+        help_text='This is the stored value, required',
+    )
+
+    display_index = models.IntegerField(
+        verbose_name="display index",
+        default=0,
+        db_index=True,
+        help_text=(
+            'Index to control display order if not alphabetical, not required'),
+    )
+
+    field_name = models.CharField(
+        max_length=25,
+        editable=False,
+        null=True,
+        blank=True,
+        help_text='Not required',
+    )
+
+    version = models.CharField(
+        max_length=35,
+        editable=False,
+        default='1.0',
+    )
+    objects = ListModelManager()
+
+    def __str__(self):
+        return self.name
+
+    def save(self, *args, **kwargs):
+        if not self.short_name:
+            self.short_name = self.name
+        super().save(*args, **kwargs)
+
+    def natural_key(self):
+        return (self.short_name, )
+
+    class Meta:
+        abstract = True
+        ordering = ['display_index', 'name']

edc_list_data/preload_data.py

@@ -19,15 +19,19 @@ def __init__(self, list_data=None, model_data=None, unique_field_data=None):
         self.list_data = list_data or {}
         self.model_data = model_data or {}
         self.unique_field_data = unique_field_data or {}
+
         self.load_list_data()
-        self.load_model_data()
-        self.update_unique_field_data()
+
+        if self.model_data:
+            self.load_model_data()
+        if self.unique_field_data:
+            self.update_unique_field_data()
 
     def load_list_data(self):
         """Loads data into a list model.
 
         List models have short_name, name where short_name
-        is the unique field.
+        is the unique field / stored field.
 
         Format:
             {model_name1: [(short_name1, name),
@@ -39,19 +43,23 @@ def load_list_data(self):
         for model_name in self.list_data.keys():
             try:
                 model = django_apps.get_model(model_name)
-                for data in self.list_data.get(model_name):
-                    short_name, display_value = data
+                display_index = 0
+                for display_index, value in enumerate(self.list_data.get(model_name)):
+                    store_value, display_value = value
                     try:
-                        obj = model.objects.get(short_name=short_name)
+                        obj = model.objects.get(short_name=store_value)
                     except ObjectDoesNotExist:
                         model.objects.create(
-                            short_name=short_name, name=display_value)
+                            short_name=store_value,
+                            name=display_value,
+                            display_index=display_index)
                     else:
                         obj.name = display_value
+                        obj.display_index = display_index
                         obj.save()
-            except Exception as e:
-                raise PreloadDataError(e)
-                # sys.stdout.write(style.ERROR(str(e) + '\n'))
+            except ValueError as e:
+                raise PreloadDataError(
+                    f'{e} See {self.list_data.get(model_name)}.')
 
     def load_model_data(self):
         """Loads data into a model, creates or updates existing.