mapping

Overview ¶

Package mapping provides the API to convert data coming from Big Table into a data.Set.

The mapping system is based on a set of rules described inside a JSON mapping file, here's an example:

{
  "raws": {
	"ui": "user_id"
  },
  "mapped": {
	"oi": {
	  "name": "is_opted_in",
	  "values": {
		"0": "false",
		"1": "true"
	  }
	}
  },
  "reversed": [
	{
	  "name": "order_status",
	  "values": {
		"1": "pending_payment",
		"2": "failed",
		"3": "processing",
		"4": "completed",
		"5": "on_hold",
		"6": "canceled",
		"7": "refunded"
	  }
	}
  ]
}

The mapping has 3 sections:

• raws: only the column qualifier is translated from its short version to a meaningful name.
• mapped: the column qualifier is translated from its short version to a meaningful name, and the value is translated from its short-value to the full value.
• reversed: the column qualifier contains the real data which is mapped to a value as described in the "values" property and the column name is taken from the "name" attribute.

Considering the mapping above, let's say we have a row with the following data coming from Big Table:

{
  "ui": "12345",
  "oi": "1",
  "3": "1"
}

The mapping system will map it to a new data.Event containing the following data:

{
  "user_id": "12345",
  "is_opted_in": "true",
  "order_status": "processing"
}