Feature: Implement custom fields for documents (#4502)

Adds custom fields of certain data types, attachable to documents and searchable

Co-Authored-By: Trenton H <797416+stumpylog@users.noreply.github.com>

src/documents/models.py

@@ -877,9 +877,139 @@ class ConsumptionTemplate(models.Model):
         return f"{self.name}"
 
 
+class CustomField(models.Model):
+    """
+    Defines the name and type of a custom field
+    """
+
+    class FieldDataType(models.TextChoices):
+        STRING = ("string", _("String"))
+        URL = ("url", _("URL"))
+        DATE = ("date", _("Date"))
+        BOOL = ("boolean"), _("Boolean")
+        INT = ("integer", _("Integer"))
+        FLOAT = ("float", _("Float"))
+        MONETARY = ("monetary", _("Monetary"))
+
+    created = models.DateTimeField(
+        _("created"),
+        default=timezone.now,
+        db_index=True,
+        editable=False,
+    )
+
+    name = models.CharField(max_length=128)
+
+    data_type = models.CharField(
+        _("data type"),
+        max_length=50,
+        choices=FieldDataType.choices,
+        editable=False,
+    )
+
+    class Meta:
+        ordering = ("created",)
+        verbose_name = _("custom field")
+        verbose_name_plural = _("custom fields")
+        constraints = [
+            models.UniqueConstraint(
+                fields=["name"],
+                name="%(app_label)s_%(class)s_unique_name",
+            ),
+        ]
+
+    def __str__(self) -> str:
+        return f"{self.name} : {self.data_type}"
+
+
+class CustomFieldInstance(models.Model):
+    """
+    A single instance of a field, attached to a CustomField for the name and type
+    and attached to a single Document to be metadata for it
+    """
+
+    created = models.DateTimeField(
+        _("created"),
+        default=timezone.now,
+        db_index=True,
+        editable=False,
+    )
+
+    document = models.ForeignKey(
+        Document,
+        blank=False,
+        null=False,
+        on_delete=models.CASCADE,
+        related_name="custom_fields",
+        editable=False,
+    )
+
+    field = models.ForeignKey(
+        CustomField,
+        blank=False,
+        null=False,
+        on_delete=models.CASCADE,
+        related_name="fields",
+        editable=False,
+    )
+
+    # Actual data storage
+    value_text = models.CharField(max_length=128, null=True)
+
+    value_bool = models.BooleanField(null=True)
+
+    value_url = models.URLField(null=True)
+
+    value_date = models.DateField(null=True)
+
+    value_int = models.IntegerField(null=True)
+
+    value_float = models.FloatField(null=True)
+
+    value_monetary = models.DecimalField(null=True, decimal_places=2, max_digits=12)
+
+    class Meta:
+        ordering = ("created",)
+        verbose_name = _("custom field instance")
+        verbose_name_plural = _("custom field instances")
+        constraints = [
+            models.UniqueConstraint(
+                fields=["document", "field"],
+                name="%(app_label)s_%(class)s_unique_document_field",
+            ),
+        ]
+
+    def __str__(self) -> str:
+        return str(self.field.name) + f" : {self.value}"
+
+    @property
+    def value(self):
+        """
+        Based on the data type, access the actual value the instance stores
+        A little shorthand/quick way to get what is actually here
+        """
+        if self.field.data_type == CustomField.FieldDataType.STRING:
+            return self.value_text
+        elif self.field.data_type == CustomField.FieldDataType.URL:
+            return self.value_url
+        elif self.field.data_type == CustomField.FieldDataType.DATE:
+            return self.value_date
+        elif self.field.data_type == CustomField.FieldDataType.BOOL:
+            return self.value_bool
+        elif self.field.data_type == CustomField.FieldDataType.INT:
+            return self.value_int
+        elif self.field.data_type == CustomField.FieldDataType.FLOAT:
+            return self.value_float
+        elif self.field.data_type == CustomField.FieldDataType.MONETARY:
+            return self.value_monetary
+        raise NotImplementedError(self.field.data_type)
+
+
 if settings.AUDIT_LOG_ENABLED:
     auditlog.register(Document, m2m_fields={"tags"})
     auditlog.register(Correspondent)
     auditlog.register(Tag)
     auditlog.register(DocumentType)
     auditlog.register(Note)
+    auditlog.register(CustomField)
+    auditlog.register(CustomFieldInstance)