Shadow fields in form data

Configuration of shadow fields for app.

In some cases, it can be useful to store additional information for a form that is not necessarily important when retrieving finalized data for internal systems. This may include values used in form dynamics or calculations which are not a relevant part of the submitted data.

By utilizing shadow field functionality, you can store all such data along with the rest of the form data during the process and then remove unnecessary data before retrieving it for processing in internal systems.

Configuration

In the data model

Shadow fields are set up in the same way as other form fields in the data model, but with a self-chosen prefix. This means that if you choose, for example, SF_ as the prefix, a helper field in the data model could be named SF_myHelperField.

This is done by changing field names in the data modeling tool. Make sure to press “Generate Models” after the changes to include updates in the C# model and possibly the XSD.

NOTE! If you change field names in a data model that is already used in a form, you must go into the relevant form component and update to the new field name, as this is not done automatically.

Removing helper field data directly from form data

To ensure that the fields set up as helper fields in the data model are removed from the submitted data, you need to configure the corresponding data type in App/config/applicationMetadata.json.

1. Find the data type that points to the relevant data model.
2. In the appLogic object, add:

   "shadowFields": {
       "prefix": <chosen prefix>
   }
   

For example, with the prefix used in the example above, the data type would be:

"dataTypes": [
    {
        "id": "my-model",
        "allowedContentTypes": [
            "application/xml"
        ],
        "appLogic": {
            "autoCreate": true,
            "classRef": "Altinn.App.Models.myModel",
            "shadowFields": {
                "prefix": "SF_"
            }
        }
    }
]

All fields in the data model that start with SF_ will then be removed from the form data upon submission so that when you later retrieve the data for processing, those fields will not be included.

Saving a copy of form data without helper fields

There may be cases where it is desirable to keep the form data as it was upon submission and instead create a copy that contains only the relevant data (i.e., without helper fields). For example, in cases where helper fields are used to control dynamics for displaying/hiding components, which may affect the appearance of the PDF receipt.

If you want to keep the form data as submitted and save a copy with only the relevant data (i.e., without helper fields), you can set it up in applicationMetadata in the same way as above, but with an additional configuration specifying the data type to use for storing the copy. You can either create a separate data type (which may make it easier to find the correct data element to retrieve later) or specify the same data type that you are configuring (thus saving a copy of the same data type).

1. Find the data type that points to the relevant data model.
2. In the appLogic object, add:

   "shadowFields": {
       "prefix": <chosen prefix>,
       "saveToDataType": <chosen data type>
   }
   

Example with the same data type

"dataTypes": [
    {
        "id": "my-model",
        "allowedContentTypes": [
            "application/xml"
        ],
        "appLogic": {
            "autoCreate": true,
            "classRef": "Altinn.App.Models.myModel",
            "shadowFields": {
                "prefix": "SF_",
                "saveToDataType": "my-model"
            }
        }
    }
]

Example with a different data type

"dataTypes": [
    {
        "id": "my-model",
        "allowedContentTypes": [
            "application/xml"
        ],
        "appLogic": {
            "autoCreate": true,
            "classRef": "Altinn.App.Models.myModel",
            "shadowFields": {
                "prefix": "SF_",
                "saveToDataType": "my-model-copy"
            }
        },
        ...
    },
    {
        "id": "my-model-copy",
        "allowedContentTypes": [
            "application/xml"
        ],
        "appLogic": {
            "autoCreate": false,
            "classRef": "Altinn.App.Models.myModel",
        },
        ...
    }
]