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Adaptors in React DataManager component

25 Jan 2022 / 9 minutes to read

Each data source or remote service uses different way in accepting request and sending back the response. DataManager cannot anticipate every way a data source works. To tackle this problem the DataManager uses the adaptor concept to communicate with particular data source.

For local data sources, the role of the data adaptor is to query the JavaScript object array based on the Query object and manipulate them.

When comes with remote datasource, the data adaptor is used to send the request that the server can understand and process the server response.

The adaptor can be assigned using the adaptor property of the DataManager.

Json adaptor

JsonAdaptor is used to query and manipulate JavaScript object array.

Source

Preview

App.tsx

rowTemplate.tsx

orders.tsx

import { DataManager, JsonAdaptor, Query } from '@syncfusion/ej2-data';
import * as React from 'react';
import { data } from './datasource';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

export default class App extends React.Component<{}, {}>{

    public result: object[] = new DataManager({ json: data, adaptor: new JsonAdaptor })
        .executeLocal(new Query().take(8));

    public items: object[] = this.result.map((row: IOrders) => (<Row {...row}/>));
    public render() {
    return (<table id='datatable' className='e-table'>
            <thead>
             <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
            </thead>
            <tbody>{this.items}</tbody>
           </table>);
    }

}

import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tr>
                 <td>{item.OrderID}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

export interface IOrders {
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

Url adaptor

UrlAdaptor act as the base adaptor for interacting with remote data services. Most of the built-in adaptors are derived from the UrlAdaptor.

import { DataManager, Query, ReturnOption, UrlAdaptor } from '@syncfusion/ej2-data';

const SERVICE_URI: string = 'http://controller.com/actions';

    new DataManager({
        adaptor: new UrlAdaptor,
        url: SERVICE_URI
    }).executeQuery(new Query().take(8)).then((e: ReturnOption) => {
        // e.result will contain the records
    });

UrlAdaptor expects response as a JSON object with properties result and count which contains the collection of entities and the total number of records respectively.

The sample response object should be as follows,

{
    "result": [{..}, {..}, {..}, ...],
    "count": 67
}

OData adaptor

OData is standardized protocol for creating and consuming data. You can retrieve data from OData service using DataManager. The ODataAdaptor helps you to interact with OData service. You can refer to the following code example of remote Data binding using OData service.

Source

Preview

App.tsx

rowTemplate.tsx

orders.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, ODataAdaptor, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';


const SERVICE_URI: string = 'https://js.syncfusion.com/demos/ejServices/Wcf/Northwind.svc/Orders';

export default class App extends React.Component<{}, {}>{
    constructor(props: object) {
        super(props);
        this.state = { items: [] };
        new DataManager({ url: SERVICE_URI, adaptor: new ODataAdaptor })
            .executeQuery(new Query().take(8))
            .then((e: ReturnOption) => {
                const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
                this.setState({
                    items: res
                });
            });
     }

    public render() {
        return (<table id='datatable' className='e-table'>
                <thead>
                    <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
                </thead>
                <tbody>{ getValue('items', this.state) }</tbody>
            </table>)
    }

}

import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tr>
                 <td>{item.OrderID}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

export interface IOrders {
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

By default, ODataAdaptor is used by DataManager.

ODataV4 adaptor

The ODataV4 is an improved version of OData protocols and the DataManager can also retrieve and consume OData v4 services. For more details on OData v4 Services, refer the odata documentation. You can use the ODataV4Adaptor to interact with ODataV4 service.

Source

Preview

App.tsx

rowTemplate.tsx

orders.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, ODataV4Adaptor, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';

const SERVICE_URI: string =  'https://services.odata.org/V4/Northwind/Northwind.svc/Orders/';

export default class App extends React.Component<{}, {}>{
    constructor(props: object) {
        super(props);
        this.state = { items: [] };
        new DataManager({ url: SERVICE_URI, adaptor: new ODataV4Adaptor })
            .executeQuery(new Query().take(8))
            .then((e: ReturnOption) => {
                const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
                this.setState({
                    items: res
                });
            });
     }

    public render() {
        return (<table id='datatable' className='e-table'>
                <thead>
                    <tr><th>Order ID</th><th>Customer ID</th><th>Employee ID</th></tr>
                </thead>
                <tbody>{ getValue('items', this.state) }</tbody>
            </table>)
    }

}

import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tr>
                 <td>{item.OrderID}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

export interface IOrders {
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

Web API adaptor

You can use the WepApiAdaptor to interact with Web API created with OData endpoint. The WebApiAdaptor is extended from the ODataAdaptor. Hence to use WebApiAdaptor, the endpoint should understand the OData formatted queries send along with request.

To enable OData query option for Web API, please refer to the documentation

import { DataManager, Query, ReturnOption, WebApiAdaptor } from '@syncfusion/ej2-data';

    const SERVICE_URI: string = 'http://controller.com/api';

    new DataManager({
        adaptor: new WebApiAdaptor,
        url: SERVICE_URI
    }).executeQuery(new Query().take(8)).then((e: ReturnOption) => {
        // e.result will contain the records
    });

WebApiAdaptor expects JSON response from the server and the response object should contain properties Items and Count whose values are collection of entities and total count of the entities respectively.

The sample response object should look like below.

{
    Items: [{..}, {..}, {..}, ...],
    Count: 830
}

WebMethod Adaptor

The WebMethodAdaptor is used to bind data source from remote services and code behind methods. It can be enabled in Grid using Adaptor property of DataManager as WebMethodAdaptor.

For every operations, an AJAX post will be send to the specified data service.

import { DataManager, Query, ReturnOption, WebMethodAdaptor } from '@syncfusion/ej2-data';

    const SERVICE_URI: string = 'http://controller.com/api';

    new DataManager({
        adaptor: new WebMethodAdaptor,
        url: SERVICE_URI
    }).executeQuery(new Query().take(8)).then((e: ReturnOption) => {
        // e.result will contain the records
    });

WebMethodAdaptor expects JSON response from the server and the response object should contain properties result and count whose values are collection of entities and total count of the entities respectively.

The sample response object should look like below.

{
    result: [{..}, {..}, {..}, ...],
    count: 830
}

The controller method’s data parameter name must be value.

GraphQL Adaptor

The GraphQLAdaptor provides an option to retrieve data from the GraphQL server. It performs CRUD and data operations such as paging, sorting, filtering etc by sending the required arguments to the server.

You can provide the GraphQL query string by using the query property of the GraphQLAdaptor. Since, the GraphQLAdaptor is extended from the UrlAdaptor, it expects response as a JSON object with properties result and count which contains the collection of entities and the total number of records respectively. The GraphQL response should be returned in JSON format like { “data”: { … }} with query name as field, you need to set the result and count properties to map the response.

import { DataManager, Query, GraphQLAdaptor } from '@syncfusion/ej2-data';

const SERVICE_URI: string = 'http://controller.com/actions';

new DataManager({
        url: SERVICE_URI, adaptor: new GraphQLAdaptor({
        response: {
            result: 'getOrders.OrderData',
            count: 'getOrders.OrderCount'
        },
        query: `query getOrders($datamanager: String) {
            getOrders(datamanager: $datamanager) {
                OrderCount,
                OrderData{OrderID, CustomerID, EmployeeID, ShipCity, ShipCountry}
             }
    }`
    })
    }).executeQuery(new Query().take(8)).then((e) => {
        //e.result will contain the records
    });

The Schema for the GraphQL server is

input OrderInput {
  OrderID: Int!
  CustomerID: String!
  EmployeeID: Int!
  ShipCity: String!
  ShipCountry: String!
}

type Order {
  OrderID: Int!
  CustomerID: String!
  EmployeeID: Int!
  ShipCity: String!
  ShipCountry: String!
}

type ReturnType {
  getOrders: [Order]
  count: Int
}

type Query {
  getOrders(datamanager: String): ReturnType
}
type Mutation {
  createOrder(value: OrderInput): Order!
  updateOrder(key: Int!, keyColumn: String, value: OrderInput): Order
  deleteOrder(key: Int!, keyColumn: String, value: OrderInput): Order!
}

The resolver for the corresponding action is

import { data } from "./db";

const resolvers = {
  Query: {
    getOrders: (parent, { datamanager }, context, info) => {
      if (datamanager.search) {
        // Perform searching
      }
      if (datamanager.sorted) {
        // Perform sorting
      }
      if (datamanager.where) {
        // Perform filtering
      }
      if (datamanager.search) {
        // Perform search
      }
      if (datamanager.skip && datamanager.take) {
        // Perform Paging
      }
      return { OrderData: data, OrderCount: data.length };
    }
  },
  Mutation: {
    createOrder: (parent, { value }, context, info) => {
      // Perform Insert
      return value;
    },
    updateOrder: (parent, { key, keyColumn, value }, context, info) => {
      // Perform Update
      return value;
    },
    deleteOrder: (parent, { key, keyColumn, value }, context, info) => {
      // Perform Delete
      return value;
    },
  }
};

export default resolvers;

The query parameters will be send in a string format which contains the below details.

Parameters	Description
`RequiresCounts`	If it is `true` then the total count of records will be included in response.
`Skip`	Holds the number of records to skip.
`Take`	Holds the number of records to take.
`Sorted`	Contains details about current sorted column and its direction.
`Where`	Contains details about current filter column name and its constraints.
`Group`	Contains details about current Grouped column names.

Performing CRUD action with GraphQLAdaptor

You can perform the CRUD actions by returning the mutation queries inside the getMutation method based on the action.

import { DataManager, Query, GraphQLAdaptor } from '@syncfusion/ej2-data';

const SERVICE_URI: string = 'http://controller.com/actions';

new DataManager({
        url: SERVICE_URI, adaptor: new GraphQLAdaptor({
        response: {
            result: 'getOrders.getOrders',
            count: 'getOrders.count'
        },
        query: `query getOrders($datamanager: String) {
            getOrders(datamanager: $datamanager) {
                count,
                getOrders{OrderID, CustomerID, EmployeeID, ShipCity, ShipCountry}
             }
    }`,
    getMutation: function (action): string {
            if (action === 'insert') {
                return `mutation CreateOrderMutation($value: OrderInput!){
                                        createOrder(value: $value){
                                            OrderID, CustomerID, EmployeeID, ShipCity, ShipCountry
                                    }}`;
            }
            if (action === 'update') {
                return `mutation Update($key: ID!, $keyColumn: String,$value: OrderInput){
                            updateOrder(key: $key, keyColumn: $keyColumn, value: $value) {
                                OrderID, CustomerID, EmployeeID, ShipCity, ShipCountry
                            }
                            }`;
            } else {
                return `mutation Remove($key: ID!, $keyColumn: String, $value: OrderInput){
                    deleteOrder(key: $key, keyColumn: $keyColumn, value: $value) {
                                OrderID, CustomerID, EmployeeID, ShipCity, ShipCountry
                            }
                            }`;
            }
        }
    })
    }).executeQuery(new Query().take(8)).then((e) => {
        //e.result will contain the records
    });

Writing custom adaptor

Sometimes the built-in adaptors does not meet your requirement. In such cases you can create your own adaptor.

To create and use custom adaptor, please refer to the below steps.

Select an built-in adaptor which will act as base class for your custom adaptor.
Override the desired method to achieve your requirement.
Assign the custom adaptor to the adaptor property of DataManager.

For the sake of demonstrating custom adaptor approach, we are going to see how to add serial number for the records by overriding the built-in response processing using processResponse method of the ODataV4Adaptor.

Source

Preview

App.tsx

rowTemplate.tsx

orders.tsx

serialNoAdaptor.tsx

import { getValue } from '@syncfusion/ej2-base';
import { DataManager, Query, ReturnOption } from '@syncfusion/ej2-data';
import * as React from 'react';
import { IOrders } from './orders';
import { Row } from './rowTemplate';
import { SerialNoAdaptor } from './serialNoAdaptor';

const SERVICE_URI: string =  'https://services.odata.org/V4/Northwind/Northwind.svc/Orders/';

export default class App extends React.Component<{}, {}>{
constructor(props: object) {
    super(props);
    this.state = { items: [] };
    new DataManager({ url: SERVICE_URI, adaptor: new SerialNoAdaptor })
        .executeQuery(new Query().take(8))
        .then((e: ReturnOption) => {
            const res = (e.result as IOrders[]).map((row: IOrders) => (<Row {...row}/>));
            this.setState({
                items: res
            });
        });
 }

public render() {
    return (<table id='datatable' className='e-table'>
            <thead>
                <tr><th>SNO</th><th>Customer ID</th><th>Employee ID</th></tr>
            </thead>
            <tbody>{ getValue('items', this.state) }</tbody>
        </table>)
}

}

import * as React from 'react';
import { IOrders } from './orders';

export class Row extends React.Component<{}, {}>{
    public render() {
        const item: IOrders = this.props as IOrders; 
        return (<tr>
                 <td>{item.SNO}</td>
                 <td>{item.CustomerID}</td>
                 <td>{item.EmployeeID}</td>
                </tr>)
    }
}

export interface IOrders {
    SNO: number,
    OrderID: number; 
    EmployeeID: number; 
    CustomerID: string; 
    Order_Details: object[]; 
}

import { setValue } from '@syncfusion/ej2-base';
import { ODataV4Adaptor } from '@syncfusion/ej2-data';

export class SerialNoAdaptor extends ODataV4Adaptor {
    public processResponse() {
        let i: number = 0;
        // calling base class processResponse function
        const original: object[] = super.processResponse.apply(this, arguments);
        // adding serial number
        original.forEach((item: object) =>  setValue('SNO', ++i, item));
        return original;
    }
}

Contents

Json adaptor
Url adaptor
OData adaptor
ODataV4 adaptor
Web API adaptor
WebMethod Adaptor
GraphQL Adaptor
Performing CRUD action with GraphQLAdaptor
Writing custom adaptor

Contents

Json adaptor
Url adaptor
OData adaptor
ODataV4 adaptor
Web API adaptor
WebMethod Adaptor
GraphQL Adaptor
Performing CRUD action with GraphQLAdaptor
Writing custom adaptor

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