loopback-ds-model-changes-mixin

Loopback Model Change Mixin

Inspired by Loopback Auditz. Offers less functionality but more customization.

Usage

Note: This mixin attempts to make not assumption about how you have setup your models and will not setup any models or properties for you. You must setup your tracking models yourself, either by extending the model they track or creating a new model with the properties you with to track on them.

Installation

npm install loopback-ds-model-changes-mixin

mode-config.json:

{
  "_meta": {
    "mixins": [
      "../node_modules/loopback-ds-model-changes-mixin"
    ]
  },
}

Basic

Minimum configuration in mymodel.json (note the myModelChanges model must be configured and attached to your app manually)

{
  ...
  "mixins": {
    "ModelChanges": {
      "changeModel": "myModelChanges",
      "idKeyName": "myModelId"
    }
  }
}

This will log all CUD operations to the model myModelChanges using the foreign key myModelId e.g.

Default Behaviour

The default behavior is as follows:

1. Every model key will be recorded for every action
2. Updates will record the full new state of the model (not just the changes)
3. The property for the action name is called 'action'

All of this can be customised (see below)

Tracking Date

The mixin does not track the timestamp of actions by default. This can be done easily by applying the [https://www.npmjs.com/package/loopback-ds-timestamp-mixin](Loopback Timestamp Mixin) to your change tracking model or by adding a date property to your change model with defaultFn: "now"`.

Whitelist and Blacklist Properties

If you only wish to log changes to specific properties, put the property names in the whitelist array option:

{
  "properties": {
    "name": "string",
    "description": "string"
  },
  "mixins": {
    "ModelChanges": {
      "changeModel": "myModelChanges",
      "idKeyName": "myModelId",
      "whitelist": ["name"]
    }
  }
}

The above will only log modifications to the "name" property on MyModel

You can also blacklist if you prefer

{
  "properties": {
    "name": "string",
    "secret": "string"
  },
  "mixins": {
    "ModelChanges": {
      "changeModel": "myModelChanges",
      "idKeyName": "myModelId",
      "blacklist": ["secret"]
    }
  }
}

Only Log Changes

The default behaviour logs the full model state for every update. If you would like to only store what changed, enable deltas:

{
  ...
  "mixins": {
    "ModelChanges": {
      "changeModel": "myModelChanges",
      "idKeyName": "myModelId",
      "deltas": true
    }
  }
}

In the above config, if you only change the name property in an update, no value for description would be stored in myModelChanges.

Changing the Action Property

By default, the column used for the name of the logged action ('create', 'update' or 'delete') is 'action'. Change this by passing actionKey to the config:

{
  ...
  "mixins": {
    "ModelChanges": {
      "changeModel": "myModelChanges",
      "idKeyName": "myModelId",
      "actionKey": "model_action"
    }
  }
}

Tracking User ID

To track user id you will need to install Loopback Component Remote Context (requires Loopback 2.37+) and ensure that it is configured for any models you wish to track:

component-config.json

  "loopback-component-remote-ctx": {
    "enabled": true,
    "whiteList": ["myModel"],
    "argName": "remoteCtx",
    "argName": "remoteCtx" // optional
  }

my-model.json

  "mixins": {
    "ModelChanges": {
      // ...
      "trackUsersAs": "userId",
      "trackUsersFrom": "userId", //optional
      "remoteCtx": "remoteCtx" // optional
    }
  }

Where trackUsersAs signifies the property that you wish to use to store the userId on the tracking model, trackUsersFrom is the property on accessToken that stores the user id (default is userId) and remoteCtx is the custom argName you specified for loopback-component-remote-ctx in component-config.json (defaults to remoteCtx).

Tracking Remote Method

To track remote method names you will need to install Loopback Component Remote Context (requires Loopback 2.37+) and ensure that it is configured for any models you wish to track (See Tracking User Id for setup).

If you wish to track the remote method name used for actions, specify the remoteMethod property in your model config:

  "mixins": {
    "ModelChanges": {
      // ...
      "remoteMethod": "remoteMethod"
    }
  }

This will store the remote method name in the remoteMethod property of your tracking model. You can also specify if you only watch to track actions that come from remote methods:

  "mixins": {
    "ModelChanges": {
      // ...
      "remoteMethod": "remoteMethod",
      "remoteOnly": true"
    }
  }

Custom Action Names

By default, the actions are stored as 'create', 'update' and 'delete. These can be customised with the mixin properties createActionName, updateActionName and deleteActionName

Dev

Tests

npm install && npm test