loopback-changes-history-mixin

loopback-changes-history-mixin
===============

 

Loopback mixin to generate a new model to save history changes by record of a model.

Installation

npm install loopback-changes-history-mixin --save

Usage

Add the mixins property to your server/model-config.json:

``json
{
"_meta": {
"sources": [
"loopback/common/models",
"loopback/server/models",
"../common/models",
"./models"
],
"mixins": [
"loopback/common/mixins",
"../node_modules/loopback-changes-history-mixin",
"../common/mixins"
]
}
}
`

Add mixin params in model definition. Example:
`
{
"name": "Person",
"properties": {
"name": "string",
"email": "string",
"status": "string",
"description": "string"
},
"mixins": {
"ChangeHistory": true
}
}
`

In the above definition it will define the following:
- A model called Person_history with properties indicated in fields: name, email, status and description.
- Relation Person has many history (model Person_history, foreign key _recordId).
- Relation Person_history belongs record (model Person, foreign key _recordId).
- Properties _version and _hash as string in models Person and Person_history.
- Properties _action as string and _update as date in model Person_history.

Every time a change is made in a record of Person, it will be saved in Person_history a record with new values
and the following fields:
- _version =
- _hash =
- _action = <'create' or 'update' or 'delete'>
- _update =

Options

The mixin supports the following parameters:

Name | Type | Default | Optional | Description
----------------------|-------------------------|------------------------|----------|------------
fields | array or string | | No | Array with the fields to version
modelName | string | ${ModelName}_history | No | Name to history model
relationName | string | history | No | Model has many history model relation name
relationParentName | string | _record | No | History model belongs to model relation name
relationForeignKey | string | _recordId | No | Foreign key for relations
versionFieldName | string | _version | No | Field name to version code
versionFieldLen | number | 5 | No | Length to versionField
hashFieldName | string or false | _hash | Yes | Field name to hash code
hashFieldLen | number | 10 | No | Length to hashField
actionFieldName | string or false | _action | Yes | Field name to action name
updatedFieldName | string or false | _update | Yes | Field name to update date

Notes:
- hashFieldName allow create a history change only if any property in fields was alter. If setup hashFieldName: false then a history change will be creates with update method called.
- If hashFieldName is false then hashFieldLen is. ignoored.

Loopback methods

Generates create records
- Model.create
- Model.updateOrCreate (AKA Model.upsert)
- Model.findOrCreate
- Model.replaceOrCreate
- Model.upsertWithWhere (view Model.upsertWithWhere section below)

Generates update records
- Model.updateOrCreate (AKA Model.upsert)
- Model.replaceOrCreate
- Model.upsertWithWhere (view Model.upsertWithWhere section below)
- Model.replaceById
- Model.prototype.save
- Model.prototype.updateAttribute
- Model.prototype.updateAttributes
- Model.prototype.replaceAtributes

Generates destroy records
- Model.prototype.delete (AKA Model.prototype.destroy)
- Model.deleteById (AKA Model.destroyById)

Unsupported methods
- Model.updateAll
- Model.deleteAll (AKA Model.destroyAll)

$3


To create history change with method upsertWithWhere option instanceByWhere: true must be passed:
`js
const where = { / ... /};
const data = { / ... / };
Person.upsertWithWhere(where, data, { instanceByWhere: true });
`

Troubles

If you have any kind of trouble with it, just let me now by raising an issue on the GitHub issue tracker here:

https://github.com/arondn2/loopback-changes-history-mixin/issues

Also, you can report the orthographic errors in the READMEs files or comments. Sorry for that, English is not my main language.

Tests

npm test or npm run cover`