Defining computed values

Each app can have some specific data transformations needed. Now this can be done via building service that handles this in js, but often times transformation is simple enough that it is easier to define it as a computed value in manifest.

Usage

In root level of the manifest, inside config section, we can define computed_values object.

Example:

{
  "config": {
    // ...
    "computed_values": {
      "policy_start_date": {
        "value": {
          "type": "jsonlogic",
          "schema": {
            "var": "active_policy.quote.customer_input.start_date"
          }
        }
      }
    }
  }
}

In this example input value policy_start_date will be updated whenever value active_policy.quote.customer_input.start_date changes with the value it changed to.

update_when_changes

There are some cases where we don't want to update value when it changes. In those cases we can define dependency logic in update_when_changes that will handle change detecton instead of value.

Example:

{
  "config": {
    // ...
    "computed_values": {
      "data.agents_count": {
        "value": {
          "type": "jsonlogic",
          "schema": {
            "+": [
              {
                "length": {
                  "var": "input.data.agents"
                }
              },
              {
                "var": "input.data.additional_count"
              }
            ]
          }
        },
        "update_when_changes": {
          "type": "jsonlogic",
          "schema": {
            "var": "input.data.additional_count"
          }
        }
      }
    }
  }
}

In this example data.agents_count input value will only update when input.data.additional_count value changes. This would improve performance if input.data.agents is static value and we don't want to listen for changes in there.

skip_form

All of the computed values will automatically update input and form state. By adding skip_form property we can set this value to be only sent to input.

Example:

{
  "config": {
    // ...
    "computed_values": {
      "hello": {
        "value": {
          "type": "jsonlogic",
          "schema": "Hello world"
        },
        "skip_form": true
      }
    }
  }
}

In this example hello value will only be set in input state and not form. Meaning this will not update field values in current screen without watch_changes enabled on form.