Change in mirror column settings, to support multi-board mirrorring

Mirror columns can now be connected to multiple columns on different boards. Therefore, the settings_str for any mirror columns that support this functionality will have a different JSON structure.

If your app uses this data, you must support both JSON formats.

The linked columns will now be stored in the displayed_linked_columns key, instead of the displayed_column key. See below for examples:

Previous format: JSON settings for mirror columns that don't support multi-board mirroring

{
  "relation_column": {
    "link_to_item" : true
  },
  "displayed_column": {
    "timeline": true
  }
}

New format: JSON settings for mirror columns that support multi-board mirroring

{
  "relation_column":{
    "link_to_item":true
  },
  "displayed_column": {},
  "displayed_linked_columns": {
    "101339646": [
      "linked_column_id"
    ]
  }
}

To support both versions, your app should check displayed_linked_columns for a value. If the key does not exist or is blank, then use the value in displayed_column.

To learn more about multi-board mirroring, check out this article: Multi-board mirroring