Mappings

open class Mappings

The Mappings builder is used to build up key/destination mappings used when optionally translating the full Dispatch payload to just the relevant data for any given Dispatcher.

Use the mapFrom method to supply the required source “key” and “destination” key, as well as any optional “path” entries required to access keys in nested object.

Using the following payload DataObject as an example (shown as JSON)

 {
      "source" : "value",
      "path": {
          "to" : [{
              "source": "nested value",
          }]
      }
 }

Simple usage for keys in the top level DataObject would look like so:

 mappings.mapFrom("source", to: "destination")

More complex versions requiring accessing keys that exist in nested objects and arrays would look like so:

 mappings.mapFrom(JSONPath["path"]["to"][0]["source"],
                  to: JSONPath["path"]["to"]["destination"])

Use the keep utility method to create a mapping where the source key is the same as the destination.

Simple usage for keys in the top level DataObject would look like so:

 mappings.keep("source")

More complex versions requiring accessing keys that exist in nested objects would look like so:

 mappings.keep(JSONPath["path"]["to"][0]["source"])

The mapFrom and keep methods return a VariableOptions that allows for setting optional properties relevant to a mapping like a ifValueEquals(:), to only perform the mapping if the value is equal to some specific string.

Use the mapConstant method to supply a constant “value” and “destination” key.

 mappings.mapConstant("value", to: "destination")

More complex versions requiring accessing keys that exist in nested objects would look like so:

 mappings.mapConstant(value, to: JSONPath["path"]["to"]["destination"])

The mapConstant method returns a ConstantOptions that allows for setting optional properties relevant to a mapping like a ifValueIn(:equals:), to only perform the mapping if a value at the given key is equal to the given target.