add DenominationValidator to validate dosage fields in Prescription m…

…odel (#1716)

* Add DosageValidator to Prescription model

* make the validator more generic

* fix migrations

* update migrations

care/facility/migrations/0398_alter_prescription_dosage_and_more.py

@@ -0,0 +1,50 @@
+# Generated by Django 4.2.5 on 2023-12-06 13:06
+
+from django.db import migrations, models
+
+import care.utils.models.validators
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("facility", "0397_truncate_discharge_time"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="prescription",
+            name="dosage",
+            field=models.CharField(
+                blank=True,
+                max_length=100,
+                null=True,
+                validators=[
+                    care.utils.models.validators.DenominationValidator(
+                        allow_floats=True,
+                        max_amount=5000,
+                        min_amount=0.0001,
+                        precision=4,
+                        units={"mg", "g", "ml", "tsp", "ampule(s)", "drop(s)"},
+                    )
+                ],
+            ),
+        ),
+        migrations.AlterField(
+            model_name="prescription",
+            name="max_dosage",
+            field=models.CharField(
+                blank=True,
+                max_length=100,
+                null=True,
+                validators=[
+                    care.utils.models.validators.DenominationValidator(
+                        allow_floats=True,
+                        max_amount=5000,
+                        min_amount=0.0001,
+                        precision=4,
+                        units={"mg", "g", "ml", "tsp", "ampule(s)", "drop(s)"},
+                    )
+                ],
+            ),
+        ),
+    ]

care/facility/models/prescription.py

@@ -7,6 +7,7 @@
 
 from care.facility.models.patient_consultation import PatientConsultation
 from care.utils.models.base import BaseModel
+from care.utils.models.validators import dosage_validator
 
 
 class FrequencyEnum(enum.Enum):
@@ -92,7 +93,9 @@ class Prescription(BaseModel):
         blank=True,
         null=True,
     )
-    dosage = models.CharField(max_length=100, blank=True, null=True)
+    dosage = models.CharField(
+        max_length=100, blank=True, null=True, validators=[dosage_validator]
+    )
 
     is_prn = models.BooleanField(default=False)
 
@@ -107,7 +110,9 @@ class Prescription(BaseModel):
 
     # prn fields
     indicator = models.TextField(blank=True, null=True)
-    max_dosage = models.CharField(max_length=100, blank=True, null=True)
+    max_dosage = models.CharField(
+        max_length=100, blank=True, null=True, validators=[dosage_validator]
+    )
     min_hours_between_doses = models.IntegerField(blank=True, null=True)
 
     notes = models.TextField(default="", blank=True)