Add new question type table supporting nested tables

* Introduce new answer type AnswerTable
* A table  format is represented by a form
* A single row is represented as a document of question row form
* JEXL expanded whereas a table answer is a list of dicts with question
  keys.
* Introduce document family to allow access to a tree of documents
  introduced through table answer.

caluma/form/factories.py

@@ -25,6 +25,7 @@ class QuestionFactory(DjangoModelFactory):
     configuration = {}
     meta = {}
     is_archived = False
+    row_form = SubFactory(FormFactory)
 
     class Meta:
         model = models.Question
@@ -59,6 +60,7 @@ class Meta:
 
 class DocumentFactory(DjangoModelFactory):
     form = SubFactory(FormFactory)
+    family = None
     meta = {}
 
     class Meta:
@@ -73,3 +75,12 @@ class AnswerFactory(DjangoModelFactory):
 
     class Meta:
         model = models.Answer
+
+
+class AnswerDocumentFactory(DjangoModelFactory):
+    answer = SubFactory(AnswerFactory)
+    document = SubFactory(DocumentFactory)
+    sort = 0
+
+    class Meta:
+        model = models.AnswerDocument

caluma/form/jexl.py

@@ -16,6 +16,7 @@ def __init__(self, answer_by_question={}, **kwargs):
         super().__init__(**kwargs)
 
         self.add_transform("answer", lambda question: answer_by_question.get(question))
+        self.add_transform("mapby", lambda arr, key: [obj[key] for obj in arr])
 
     def validate(self, expression):
         return super().validate(expression, QuestionValidatingAnalyzer)

caluma/form/migrations/0003_auto_20190128_0836.py

@@ -0,0 +1,119 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.11.18 on 2019-01-28 08:36
+from __future__ import unicode_literals
+
+import uuid
+
+import django.contrib.postgres.fields.jsonb
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [("form", "0002_auto_20181221_1517")]
+
+    operations = [
+        migrations.CreateModel(
+            name="AnswerDocument",
+            fields=[
+                ("created_at", models.DateTimeField(auto_now_add=True)),
+                ("modified_at", models.DateTimeField(auto_now=True)),
+                (
+                    "created_by_user",
+                    models.CharField(blank=True, max_length=150, null=True),
+                ),
+                (
+                    "created_by_group",
+                    models.CharField(
+                        blank=True, db_index=True, max_length=150, null=True
+                    ),
+                ),
+                (
+                    "id",
+                    models.UUIDField(
+                        default=uuid.uuid4,
+                        editable=False,
+                        primary_key=True,
+                        serialize=False,
+                    ),
+                ),
+                (
+                    "sort",
+                    models.PositiveIntegerField(
+                        db_index=True, default=0, editable=False
+                    ),
+                ),
+            ],
+            options={"ordering": ("-sort", "id")},
+        ),
+        migrations.AddField(
+            model_name="question",
+            name="row_form",
+            field=models.ForeignKey(
+                blank=True,
+                help_text="Form that represents a row of the table",
+                null=True,
+                on_delete=django.db.models.deletion.CASCADE,
+                related_name="+",
+                to="form.Form",
+            ),
+        ),
+        migrations.AlterField(
+            model_name="answer",
+            name="value",
+            field=django.contrib.postgres.fields.jsonb.JSONField(blank=True, null=True),
+        ),
+        migrations.AlterField(
+            model_name="question",
+            name="type",
+            field=models.CharField(
+                choices=[
+                    ("checkbox", "checkbox"),
+                    ("integer", "integer"),
+                    ("float", "float"),
+                    ("radio", "radio"),
+                    ("textarea", "textarea"),
+                    ("text", "text"),
+                    ("table", "table"),
+                ],
+                max_length=10,
+            ),
+        ),
+        migrations.AddField(
+            model_name="answerdocument",
+            name="answer",
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE, to="form.Answer"
+            ),
+        ),
+        migrations.AddField(
+            model_name="answerdocument",
+            name="document",
+            field=models.ForeignKey(
+                on_delete=django.db.models.deletion.CASCADE, to="form.Document"
+            ),
+        ),
+        migrations.AddField(
+            model_name="answer",
+            name="documents",
+            field=models.ManyToManyField(
+                related_name="_answer_documents_+",
+                through="form.AnswerDocument",
+                to="form.Document",
+            ),
+        ),
+        migrations.AlterUniqueTogether(
+            name="answerdocument", unique_together=set([("answer", "document")])
+        ),
+        migrations.AddField(
+            model_name="document",
+            name="family",
+            field=models.UUIDField(
+                db_index=True,
+                default=uuid.uuid4,
+                help_text="Family id which document belongs too.",
+            ),
+            preserve_default=False,
+        ),
+    ]

caluma/form/models.py

@@ -1,5 +1,7 @@
 from django.contrib.postgres.fields import JSONField
 from django.db import models
+from django.db.models.signals import post_init
+from django.dispatch import receiver
 from localized_fields.fields import LocalizedField
 
 from ..core.models import SlugModel, UUIDModel
@@ -27,13 +29,13 @@ class Meta:
 
 
 class Question(SlugModel):
-    # TODO: add descriptions
     TYPE_CHECKBOX = "checkbox"
     TYPE_INTEGER = "integer"
     TYPE_FLOAT = "float"
     TYPE_RADIO = "radio"
     TYPE_TEXTAREA = "textarea"
     TYPE_TEXT = "text"
+    TYPE_TABLE = "table"
 
     TYPE_CHOICES = (
         TYPE_CHECKBOX,
@@ -42,6 +44,7 @@ class Question(SlugModel):
         TYPE_RADIO,
         TYPE_TEXTAREA,
         TYPE_TEXT,
+        TYPE_TABLE,
     )
     TYPE_CHOICES_TUPLE = ((type_choice, type_choice) for type_choice in TYPE_CHOICES)
 
@@ -55,6 +58,13 @@ class Question(SlugModel):
     options = models.ManyToManyField(
         "Option", through="QuestionOption", related_name="questions"
     )
+    row_form = models.ForeignKey(
+        Form,
+        blank=True,
+        null=True,
+        related_name="+",
+        help_text="One row of table is represented by this form",
+    )
 
     @property
     def max_length(self):
@@ -110,6 +120,10 @@ def create_document_for_task(self, task, user):
 
 class Document(UUIDModel):
     objects = DocumentManager()
+
+    family = models.UUIDField(
+        help_text="Family id which document belongs too.", db_index=True
+    )
     form = models.ForeignKey(
         "form.Form", on_delete=models.DO_NOTHING, related_name="documents"
     )
@@ -120,12 +134,37 @@ class Answer(UUIDModel):
     question = models.ForeignKey(
         "form.Question", on_delete=models.DO_NOTHING, related_name="answers"
     )
-    value = JSONField()
+    value = JSONField(null=True, blank=True)
     meta = JSONField(default=dict)
     document = models.ForeignKey(
         Document, on_delete=models.CASCADE, related_name="answers"
     )
+    documents = models.ManyToManyField(
+        Document, through="AnswerDocument", related_name="+"
+    )
 
     class Meta:
         # a question may only be answerd once per document
         unique_together = ("document", "question")
+
+
+@receiver(post_init, sender=Document)
+def set_document_family(sender, instance, **kwargs):
+    """
+    Family id is inherited from document id.
+
+    Family will be manually set on mutation where a tree structure
+    is created.
+    """
+    if instance.family is None:
+        instance.family = instance.pk
+
+
+class AnswerDocument(UUIDModel):
+    answer = models.ForeignKey("Answer", on_delete=models.CASCADE)
+    document = models.ForeignKey("Document", on_delete=models.CASCADE)
+    sort = models.PositiveIntegerField(editable=False, db_index=True, default=0)
+
+    class Meta:
+        ordering = ("-sort", "id")
+        unique_together = ("answer", "document")