kuzzle computed-fields plugin

• kuzzle computed-fields plugin
  • Purpose
  • Usage
  • Installing the plugin
  • Computed fields management
    • Create a computed field
    • List computed fields
    • Delete a computed field

Purpose

This plugin allows creating computed fields from a document's existing fields. For instance, considering the following document:

{
  "name": "Michael",
  "surname": "Romeo"
}

you could have a computed field fullname defined as "${name} ${surname}" and whose value would be "Michael Romeo".

The computed fileds are stored in a _computedFields object to avoid collision with document fields, so the final document will be:

{
  "name": "Michael",
  "surname": "Romeo",
  "_computedFields": {
    "fullname": "Michael Romeo"
  }
}

A computed field is applied to documents in a given collection and is defined as follow:

{
  "name": "myComputedField",
  "value": "Here is my computed field using ${my_document_field} and ${a.nested.field}"
}

Usage

Field	Description
name	This is the name by which it will be represented in the documents.
value	The computed field's value is a template string where you can insert document's field values using the ${fieldname} syntax. Note that you are note limited to field at the root of the document, you can access insert nested property field using the classic . syntax: ${my.nested.field}

Note: To avoid any collision with documents fields, all computed fields are nested in _computedFields object.

Installing the plugin

Clone this repository locally and make it accessible from the plugins/enabled directory relative to the Kuzzle installation directory. A common practice is to put the code of the plugin in plugins/available and create a symbolic link to it in plugins/enabled.

Note: If you are running Kuzzle within a Docker container, you will need to mount the local plugin installation directory as a volume in the container.

Please refer to the Guide for further instructions on how to install Kuzzle plugins.

Computed fields management

Once installed, the plugin exposes a new controller: computedFields c

The controller has de following actions:

Action	Description
create	Add or update a computed field to an index/collection
delete	Remove a computed field from an index/collection
list	List computed fields of an index/collection
recompute	Recompute computed fields for all documents of a given index/collection

Create a computed field

http

You can create or update a computed field sending a http POST request to http+https://<host>:<port>/_plugin/computed-fields/<index>/<collection>

For example:

$ curl  localhost:7512/_plugin/computed-fields/myIndex/myCollection -H "Content-Type: application/json"
-d '{
  "name": "myComputedField",
  "value": "Here is my computed field using ${my_document_field} and ${a.nested.field}"
}'

Response:

{
  "requestId": "f0cef431-a642-41ba-98b5-c2f407f10bd1",
  "status": 200,
  "error": null,
  "controller": "computed-fields/field",
  "action": "create",
  "collection": "myCollection",
  "index": "myIndex",
  "volatile": null,
  "result": {
    "_index": "%plugin:computed-fields",
    "_type": "computedFields",
    "_id": "myIndex-myCollection-myComputedField",
    "_version": 1,
    "result": "created",
    "_shards": {
      "total": 2,
      "successful": 1,
      "failed": 0
    },
    "created": true,
    "_source": {
      "name": "myComputedField",
      "value": "Here is my computed field using ${my_document_field} and ${a.nested.field}"
    }
  }
}

Using Kuzzle JS SDK

Using the Kuzzle JS SDK, you can call controller actions using the query API:

  kuzzle.queryPromise(
    {
      controller: 'computed-fields/computedFields',
      action: 'create',
      body: {
      name: "myComputedField",
      index: "myIndex",
      collection: "myCollection",
      value: "Here is my computed field using ${my_document_field} and ${a.nested.field}"
    }
  )

List computed fields

The list action will return an array of computed fields for the given index/collection.

[
  { "name": "aname", "value": "a template" },
  { "name": "anotherone", "value": "another template" }
]

http

Send a GET request to http+https://<host>:<port>/_plugin/computed-fields/<index>/<collection> to get computed fields list

$ curl  localhost:7512/_plugin/computed-fields/myIndex/myCollection

Response:

{
  "requestId": "43af0e90-7e4b-40d7-bae2-665a999e3152",
  "status": 200,
  "error": null,
  "controller": "computed-fields/computedFields",
  "action": "list",
  "collection": "myCollection",
  "index": "myIndex",
  "volatile": null,
  "result": [
    {
      "name": "another-computed-field",
      "value": "A fake template",
      "_id": "my-index-1-my-first-collection-another-computed-field"
    }
  ]
}

Using Kuzzle JS SDK

Using the Kuzzle JS SDK, you can call controller actions using the query API:

kuzzle
  .queryPromise({
    controller: "computed-fields/computedFields",
    action: "list"
  })
  .then(r => console.log(r.result));

Outputs:

[
  {
    "name": "another-computed-field",
    "index": "my-index-1",
    "collection": "my-first-collection",
    "value": "A fake template",
    "_id": "my-index-1-my-first-collection-another-computed-field"
  }
]

Delete a computed field

The delete action allow one to remove a computed field.

http

Send a DELETE request to http+https://<host>:<port>/_plugin/computed-fields/<index>/<collection>/<name> to delete computed field named <name>

$ curl -X DELETE  localhost:7512/_plugin/computed-fields/my-index/my-first-collection/another-computed-field

Response:

{
  "requestId": "ab711c47-62f4-4bd0-b127-3e8012ca1135",
  "status": 200,
  "error": null,
  "controller": "computed-fields/computedFields",
  "action": "delete",
  "collection": "my-collection",
  "index": "my-index",
  "volatile": null
}

Using Kuzzle JS SDK

Using the Kuzzle JS SDK, you can call controller actions using the queryAPI:

kuzzle.queryPromise({
  controller: "computed-fields/computedFields",
  action: "delete",
  _id: "my-index-1-my-first-collection-another-computed-field"
});