Drupal JSON-API Params

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The JSON:API is part of Drupal Core.

The JSON:API specifications defines standard query parameters to be used to do filtering, sorting, restricting fields that are returned, pagination and so on.

This module provides a helper Class to create the required query. While doing so, it also tries to optimise the query by using the short form, whenever possible.


Installation

Install the package via npm:

``sh
$ npm i drupal-jsonapi-params
`

Usage

$3

Import DrupalJsonApiParams from drupal-jsonapi-params
`js
import {DrupalJsonApiParams} from 'drupal-jsonapi-params';

const apiParams = new DrupalJsonApiParams();
`

$3

`js
var drupalJsonapiParams = require("drupal-jsonapi-params")

const apiParams = new drupalJsonapiParams.DrupalJsonApiParams();
`

`js
apiParams
// Add Group within Groups.
.addGroup('publish_status', 'OR', 'parent_group')
.addGroup('child_group_B', 'AND', 'parent_group')
.addGroup('parent_group', 'AND')
// Add Filters.
.addFilter('status', '1')
// Add Filter to Group.
.addFilter('status', '2', '!=', 'publish_status')
// Add Page Limit.
.addPageLimit(5)
// Add Page Offset.
.addPageOffset(20)
// Add Fields.
.addFields('node--article', ['field_a.id', 'field_b.uid', 'field_c.tid'])
// Add Includes.
.addInclude(['field_a.id', 'field_b.uid', 'field_c.tid'])
// Add multiple sort criterion.
.addSort('id', 'DESC')
.addSort('uid')
.addSort('status');

const urlencodedQueryString = apiParams.getQueryString();
const queryString = apiParams.getQueryString({ encode: false });

`

API

$3

Returns query string which can be used in api calls. By default the output is URI encoded. Options can be passed to control the qs.stringifying internally used.

$3

Used to restrict items returned in a listing.

| Params | Type | Description |
| --- | --- | --- |
| path | string | A 'path' identifies a field on a resource
| value | string | string[] | null | A 'value' is the thing you compare against. For operators like "IN" which supports multiple parameters, you can supply an array.
| operator | string | (Optional) An 'operator' is a method of comparison
| group | string | (Optional) Name of the group, the filter belongs to

Following values can be used for the operator. If none is provided, it assumes "=" by default.

``
'=', '<>',
'>', '>=', '<', '<=',
'STARTS_WITH', 'CONTAINS', 'ENDS_WITH',
'IN', 'NOT IN',
'BETWEEN', 'NOT BETWEEN',
'IS NULL', 'IS NOT NULL'
`

NOTE: Make sure you match the value supplied based on the operators used as per the table below

| Value Type | Operator | Description |
| --- | --- | --- |
| string | =, <>, >, >=, <, <=, STARTS_WITH, CONTAINS, ENDS_WITH | |
| string[] | IN, NOT IN | |
| string[] _size 2_ | BETWEEN, NOT BETWEEN | The first item is used for min (start of the range), and the second item is used for max (end of the range).
| null | IS NULL, IS NOT NULL | Must use null


Read more about filter in Drupal.org Documentation

$3

Used to group Filters. Groups can be nested too.

|Params | Type | Description |
| --- | --- | --- |
| name | string | Name of the group
| conjunction | string | (Optional) All groups have conjunctions and a conjunction is either AND or OR.
| memberOf | string | (Optional) Name of the group, this group belongs to

$3

Used to add referenced resources inside same request. Thereby preventing additional api calls.

|Params | Type | Description |
| --- | --- | --- |
| fields | string[] | Array of field names

Read more about Includes in Drupal.org Documentation

$3

Used to return the list of items in specific order.

|Params | Type | Description |
| --- | --- | --- |
| path | string | A 'path' identifies a field on a resource
| direction | string | Sort direction ASC or DESC

Read more about Sort in Drupal.org Documentation

$3

Use to restrict max amount of items returned in the listing. Using this for pagination is tricky, and make sure you read the following document on Drupal.org to implement it correctly.

|Params | Type | Description |
| --- | --- | --- |
| limit | number | Number of items to limit to |

Read more about Pagination in Drupal.org Documentation

$3

Use to skip some items items from start of the listing. Please note that this is not the page number. To get the offset number for a page you can
multiply the number of pages you want to skip with items per page.

|Params | Type | Description |
| --- | --- | --- |
| offset | number | Number of items to skip to |

Read more about Pagination in Drupal.org Documentation

NOTE

JSON:API response have pagination information build into the response. Based on the results in the response, you can get "previous" and "next" links which can be used
to get further items when results overflows into multiple pages.

If you are looking for a practical guide, you can check out the example in this issue on GitHub https://github.com/d34dman/drupal-jsonapi-params/issues/40

$3

The name of this method might be misleading. Use this to explicitely request for specific fields on an entity.

|Params | Type | Description |
| --- | --- | --- |
| type | string | Resource type
| fields | string[] | Array of field names in the given resource type

---


$3

Use to add custom parameter to the query.

|Params | Type | Description |
| --- | --- | --- |
| input | object | The parameter object |

E.g. usage

`js
apiParams
// To add foo=bar to the query.
.addCustomParam({foo: 'bar'})
// To add foo[bar]=baz to the query.
.addCustomParam({ foo: {bar: 'baz'}})
// To add bar[0]=a&bar[1]=b&bar[2]=c to the query.
.addCustomParam({ bar: ['a', 'b', 'c']})
`

Helper methods

$3

Clears all query parameter constructed so far.

$3

Get object representation of the query object generated so far.

$3

Re-initialize with a query string/object or another instance of DrupalJsonApiParams

$3

Re-initialize with previously stored data from getQueryObject

$3

Re-initialize with previously stored data from getQueryString.
This method accepts an optional parameter to pass options to qs library when parsing the given query.

Please refer to https://www.npmjs.com/package/qs for more info about available options.

This would override any options set using setQsOptions during the given call.

$3

Set options that is passed to qs library when parsing/serializing query paramters.
Please refer to https://www.npmjs.com/package/qs for more info about available options.

$3

Get options that is passed to qs library when parsing/serializing query paramters. The value should match whatever was previously set via setQsOptions` method.