Custom Sources

Access to a custom data source is configured using the CustomStore component. DevExtreme provides ASP.NET and PHP extensions to configure the CustomStore and implement server-side data processing. You can also use the third-party extension for MongoDB.

You need to configure the CustomStore in detail for accessing a server built on another technology. Data in this situation can be processed on the client or server. In the former case, switch the CustomStore to the raw mode and load all data from the server in the load function as shown in the following example:

jQuery
JavaScript
$(function() {
    $("#listContainer").dxList({
        dataSource: new DevExpress.data.DataSource({
            store: new DevExpress.data.CustomStore({
                key: "ID",
                loadMode: "raw",   
                load: function () {
                    return $.getJSON('https://mydomain.com/MyDataService');
                }
            })
        })
    });
});
Angular
TypeScript
HTML
import { ..., Inject } from "@angular/core";
import { HttpClient, HttpClientModule } from "@angular/common/http";
import { DxListModule } from "devextreme-angular";
import DataSource from "devextreme/data/data_source";
import CustomStore from "devextreme/data/custom_store";
import "rxjs/add/operator/toPromise";
// ...
export class AppComponent {
    listDataSource: any = {};
    constructor(@Inject(HttpClient) httpClient: HttpClient) {
        this.listDataSource = new DataSource({
            store: new CustomStore({
                key: "ID",
                loadMode: "raw",   
                load: () => {
                    return httpClient.get('http://mydomain.com/MyDataService')
                        .toPromise();
                }
            })
        });
    }
}
@NgModule({
    imports: [
        // ...
        DxListModule,
        HttpClientModule
    ],
    // ...
})
<dx-list ...
    [dataSource]="listDataSource">
</dx-list>
Vue
JavaScript
HTML
import { DxList } from "devextreme-vue/list";
import CustomStore from "devextreme/data/custom_store";
import DataSource from "devextreme/data/data_source";
// ...
function handleErrors(response) {
    if (!response.ok)
        throw Error(response.statusText);
    return response;
}
const listDataSource = new DataSource({
    store: new CustomStore({
        key: "ID",
        loadMode: "raw",   
        load: () => {
            return fetch("https://mydomain.com/MyDataService")
                    .then(handleErrors);
        }
    })
});
export default {
    // ...
    data() {
        return {
            dataSource: listDataSource
        };
    },
    components: {
        // ...
        DxList
    }
}
<dx-list ... 
    :data-source="dataSource" />
React
JavaScript
import React from "react";
import List from "devextreme-react/list";
import CustomStore from "devextreme/data/custom_store";
import DataSource from "devextreme/data/data_source";
// ...
function handleErrors(response) {
    if (!response.ok)
        throw Error(response.statusText);
    return response;
}
const listDataSource = new DataSource({
    store: new CustomStore({
        key: "ID",
        loadMode: "raw",   
        load: () => {
            return fetch("https://mydomain.com/MyDataService")
                    .then(handleErrors);
        }
    })
});
class App extends React.Component {
    render() {
        return (
            <List ...
                dataSource={listDataSource}>
            </List>
        );
    }
}
export default App;
NOTE
We advise against using this mode with large amounts of data because all data is loaded at once.

In the latter case, use the CustomStore's load function to send data processing settings to the server. These settings are passed as a parameter to the load function and depend on the operations (paging, filtering, sorting, etc.) that you have enabled in the DataSource. The following settings are relevant for the List:

After receiving these settings, the server should apply them to data and send back an object with the following structure:

{
    data: [{
        key: "Group 1",
        items: [ ... ] // result data objects
    },
    ...
    ],
    totalCount: 100
}

If the server has not received the group parameter, the resulting object should be as follows:

{
    data: [ ... ], // result data objects
    totalCount: 100
}

If the List allows the user to delete items, the CustomStore must implement the remove operation as well. Below is a generalized configuration of the CustomStore for the List widget.

jQuery
JavaScript
$(function() {
    $("#listContainer").dxList({
        dataSource: new DevExpress.data.DataSource({
            key: "ID",
            load: function(loadOptions) {
                var d = $.Deferred(),
                    params = {};
                [
                    "skip",     
                    "take",  
                    "sort", 
                    "filter", 
                    "searchExpr",
                    "searchOperation",
                    "searchValue",
                    "group", 
                    "requireTotalCount"
                ].forEach(function(i) {
                    if(i in loadOptions && isNotEmpty(loadOptions[i])) 
                        params[i] = JSON.stringify(loadOptions[i]);
                });
                $.getJSON("http://mydomain.com/MyDataService", params)
                    .done(function(result) {
                        // Here, you can perform operations unsupported by the server
                        d.resolve(result.data, { 
                            totalCount: result.totalCount
                        });
                    });
                return d.promise();
            },
            remove: function(key) {
                return $.ajax({
                    url: "http://mydomain.com/MyDataService/" + encodeURIComponent(key),
                    method: "DELETE"
                });
            }
        })
    });
});
function isNotEmpty(value) {
    return value !== undefined && value !== null && value !== "";
}
Angular
TypeScript
HTML
import { ..., Inject } from "@angular/core";
import { HttpClient, HttpClientModule, HttpParams } from "@angular/common/http";
import { DxListModule } from "devextreme-angular";
import DataSource from "devextreme/data/data_source";
import CustomStore from "devextreme/data/custom_store";
import "rxjs/add/operator/toPromise";
// ...
export class AppComponent {
    listDataSource: any = {};
    constructor(@Inject(HttpClient) httpClient: HttpClient) {
        function isNotEmpty(value: any): boolean {
            return value !== undefined && value !== null && value !== "";
        }
        this.listDataSource = new DataSource({
            store: new CustomStore({
                key: "ID",
                load: (loadOptions) => {
                    let params: HttpParams = new HttpParams();
                    [
                        "skip",     
                        "take",  
                        "sort", 
                        "filter", 
                        "searchExpr",
                        "searchOperation",
                        "searchValue",
                        "group", 
                        "requireTotalCount"
                    ].forEach(function(i) {
                        if(i in loadOptions && isNotEmpty(loadOptions[i])) 
                            params = params.set(i, JSON.stringify(loadOptions[i]));
                    });
                    return httpClient.get("http://mydomain.com/MyDataService", { params: params })
                        .toPromise()
                        .then(result => {
                            // Here, you can perform operations unsupported by the server
                            return {
                                data: result.data,
                                totalCount: result.totalCount
                            };
                        });
                },
                remove: function(key) {
                    return httpClient.delete('http://mydomain.com/MyDataService' + encodeURIComponent(key))
                        .toPromise();
                }
            })
        });
    }
}
@NgModule({
    imports: [
        // ...
        DxListModule,
        HttpClientModule
    ],
    // ...
})
<dx-list
    [dataSource]="listDataSource">
</dx-list>
Vue
JavaScript
HTML
import DxList from "devextreme-vue/list";
import CustomStore from "devextreme/data/custom_store";
// ...
function isNotEmpty(value) {
    return value !== undefined && value !== null && value !== "";
}
function handleErrors(response) {
    if (!response.ok)
        throw Error(response.statusText);
    return response;
}
const listDataSource = {
    store: new CustomStore({
        key: "ID",
        load: (loadOptions) => {
            let params = "?";
            [
                "skip",     
                "take",  
                "sort", 
                "filter", 
                "searchExpr",
                "searchOperation",
                "searchValue",
                "group", 
                "requireTotalCount"
            ].forEach(function(i) {
                if(i in loadOptions && isNotEmpty(loadOptions[i])) 
                    params += `${i}=${JSON.stringify(loadOptions[i])}&`;
            });
            params = params.slice(0, -1);
            return fetch(`https://mydomain.com/MyDataService${params}`)
                .then(handleErrors)
                .then(response => response.json())
                .then((result) => {
                    return { 
                        data: result.data,
                        totalCount: result.totalCount
                    }
                });
        },
        remove: (key) => {
            return fetch(`https://mydomain.com/MyDataService/${encodeURIComponent(key)}`, {
                method: "DELETE"
            }).then(handleErrors);
        }
    })
}
export default {
    // ...
    data() {
        return {
            dataSource: listDataSource
        };
    },
    components: {
        // ...
        DxList
    }
}
<dx-list ... 
    :data-source="dataSource" />
React
JavaScript
import React from "react";
import List from "devextreme-react/list";
import CustomStore from "devextreme/data/custom_store";
// ...
function isNotEmpty(value) {
    return value !== undefined && value !== null && value !== "";
}
function handleErrors(response) {
    if (!response.ok) 
        throw Error(response.statusText);
    return response;
}
const listDataSource = {
    store: new CustomStore({
        key: "ID",
        load: (loadOptions) => {
            let params = "?";
            [
                "skip",     
                "take",  
                "sort", 
                "filter", 
                "searchExpr",
                "searchOperation",
                "searchValue",
                "group", 
                "requireTotalCount"
            ].forEach(function(i) {
                if(i in loadOptions && isNotEmpty(loadOptions[i])) 
                    params += `${i}=${JSON.stringify(loadOptions[i])}&`;
            });
            params = params.slice(0, -1);
            return fetch(`https://mydomain.com/MyDataService${params}`)
                .then(handleErrors)
                .then(response => response.json())
                .then((result) => {
                    return { 
                        data: result.data,
                        totalCount: result.totalCount
                    }
                });
        },
        remove: (key) => {
            return fetch(`https://mydomain.com/MyDataService/${encodeURIComponent(key)}`, {
                method: "DELETE"
            }).then(handleErrors);
        }
    })
}
class App extends React.Component {
    render() {
        return (
            <List ...
                dataSource={listDataSource}>
            </List>
        );
    }
}
export default App;
See Also