✨ [#4980] Add function to generate JSON schema from a form and list o…

…f variables to include

Also updated the JSON dump plugin

src/openforms/forms/utils.py

@@ -3,7 +3,7 @@
 import random
 import string
 import zipfile
-from typing import Any
+from typing import Any, Sequence
 from uuid import uuid4
 
 from django.conf import settings
@@ -16,9 +16,13 @@
 from rest_framework.test import APIRequestFactory
 
 from openforms.formio.migration_converters import CONVERTERS, DEFINITION_CONVERTERS
+from openforms.formio.registry import register as component_registry
 from openforms.formio.utils import iter_components
 from openforms.typing import JSONObject
 from openforms.variables.constants import FormVariableSources
+from openforms.variables.registry import (
+    register_static_variable as static_variable_registry,
+)
 
 from .api.datastructures import FormVariableWrapper
 from .api.serializers import (
@@ -129,6 +133,72 @@ def form_to_json(form_id: int) -> dict:
     return resources
 
 
+# TODO-4980: what should the name be? Do we need the submission, or is just the form
+#  sufficient here?
+# TODO-4980: pass form_id instead of the form?
+def form_variables_to_json_schema(
+    form: Form, variables_to_include: Sequence[str]
+) -> JSONObject:
+    """Generate a JSON schema from a form, for the specified variables.
+
+    :param form: The form to generate JSON schema for.
+    :param variables_to_include: A sequence of variables to include in the schema.
+
+    :returns: A JSON schema representing the form variables.
+    """
+
+    # Handle static variables
+    static_var_properties = {
+        key: static_variable_registry[key].as_json_schema()
+        for key in variables_to_include
+        if key in static_variable_registry
+    }
+
+    # Handle form variables
+    all_form_vars = {var.key: var for var in form.formvariable_set.all()}
+
+    # TODO-4980: add to FormVariable?
+    def get_json_schema_from_form_variable(form_variable):
+        form_def = form_variable.form_definition
+
+        component = form_def.configuration_wrapper.component_map[form_variable.key]
+        component_plugin = component_registry[component["type"]]
+
+        return component_plugin.as_json_schema(component)
+
+    form_var_properties = {
+        key: get_json_schema_from_form_variable(all_form_vars[key])
+        for key in variables_to_include
+        if key in all_form_vars
+    }
+
+    # Required
+    def is_required(form_variable):
+        form_def = form_variable.form_definition
+        component = form_def.configuration_wrapper.component_map[form_variable.key]
+
+        validate = component.get("validate", {})
+        return validate.get("required", False)
+
+    required_form_variables = [
+        var for var in form_var_properties.keys() if is_required(all_form_vars[var])
+    ]
+
+    required = [*static_var_properties.keys(), *required_form_variables]
+
+    # Result
+    var_properties = {**static_var_properties, **form_var_properties}
+    schema = {
+        "$schema": "https://json-schema.org/draft/2020-12/schema",
+        "type": "object",
+        "properties": var_properties,
+        "required": required,
+        "additionalProperties": False,
+    }
+
+    return schema
+
+
 def export_form(form_id, archive_name=None, response=None):
     resources = form_to_json(form_id)
 

src/openforms/registrations/contrib/json_dump/plugin.py

@@ -4,6 +4,7 @@
 
 from zgw_consumers.client import build_client
 
+from openforms.forms.utils import form_variables_to_json_schema
 from openforms.formio.typing import Component
 from openforms.submissions.models import Submission, SubmissionValueVariable, \
     SubmissionFileAttachment
@@ -38,19 +39,25 @@ def register_submission(
         self.process_variables(submission, values)
 
         # Generate schema
-        # TODO: will be added in #4980. Hardcoded example for now.
-        schema = {
-            "$schema": "https://json-schema.org/draft/2020-12/schema",
-            "type": "object",
-            "properties": {
-                "static_var_1": {"type": "string", "pattern": "^cool_pattern$"},
-                "form_var_1": {"type": "string"},
-                "form_var_2": {"type": "string"},
-                "attachment": {"type": "string", "contentEncoding": "base64"},
-            },
-            "required": ["static_var_1", "form_var_1", "form_var_2"],
-            "additionalProperties": False,
-        }
+        schema = form_variables_to_json_schema(submission.form, options["form_variables"])
+
+        # TODO-4980: this can be cleaned up probably
+        # Change schema of files, as we do some custom processing in this plugin
+        attachment_vars = [
+            var for var in submission.form.formvariable_set.all()
+            if var.key in set(options["form_variables"]).difference(form_vars)
+        ]
+        for variable in attachment_vars:
+            form_def = variable.form_definition
+            component = form_def.configuration_wrapper.component_map[variable.key]
+            # TODO-4980: enable this when the attachment processing is cleaned up
+            # multiple = component.get("multiple", False)
+            multiple = False
+
+            base = {"type": "string", "format": "base64"}
+            schema["properties"][variable.key] = (
+                {"type": "array", "items": base} if multiple else base
+            )
 
         # Send to the service
         json = {"values": values, "schema": schema}