DevExtreme Angular - Client-Side Exporting and Printing

Although DevExtreme data visualization widgets can be displayed on any device, a user may need a widget printed or in the form of a document. For these cases, the widgets provide client-side exporting and printing. This guide shows how to configure these features for the user, and how to export and print a widget using the API. It also explains how to set up a server-side proxy, which is necessary if you plan to support exporting and printing in Safari on MacOS.

User Interaction

To export or print a widget, a user clicks the "Exporting/Printing" button and selects a command from the drop-down menu. The Print command opens the browser's Print window that lets the user select preferred printing settings and send the print job to the printer. The other commands save a file of the selected format in the user's local storage.

DevExtreme HTML5 DataVisualization Charts Export Print

You can enable both exporting and printing by setting the export.enabled option to true. If you need only exporting to be available to the user, disable printing by assigning false to the export.printingEnabled option.

jQuery
JavaScript
$(function() {
    $("#chartContainer").dxChart({
        // ...
        export: {
            enabled: true,
            printingEnabled: false
        }
    });
});
Angular
HTML
TypeScript
<dx-chart ... >
    <dxo-export
        [enabled]="true"
        [printingEnabled]="false">
    </dxo-export>
</dx-chart>
import { DxChartModule } from "devextreme-angular";
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxChartModule
    ],
    // ...
})
Vue
App.vue
<template> 
    <DxChart ... >
        <DxExport
            :enabled="true"
            :printing-enabled="false"
        />
    </DxChart>
</template>

<script>
import DxChart, {
    DxExport
} from 'devextreme-vue/chart';

export default {
    components: {
        DxChart,
        DxExport
    }
}
</script>
React
App.js
import React from 'react';
import Chart, {
    Export
} from 'devextreme-react/chart';

class App extends React.Component {
    render() {
        return (
            <Chart ... >
                <Export
                    enabled={true}
                    printingEnabled={false}
                />
            </Chart>
        );
    }
}

export default App;

If you want to restrict the set of formats available for exporting, change the export.formats array. You can also specify the default name for the exported file using the fileName option.

jQuery
JavaScript
$(function() {
    $("#chartContainer").dxChart({
        // ...
        export: {
            enabled: true,
            formats: ["PNG", "JPEG"],
            fileName: "exported_chart"
        }
    });
});
Angular
HTML
TypeScript
<dx-chart ... >
    <dxo-export
        [enabled]="true"
        [formats]="['PNG', 'JPEG']"
        fileName="exported_chart">
    </dxo-export>
</dx-chart>
import { DxChartModule } from "devextreme-angular";
// ...
export class AppComponent {
    // ...
}
@NgModule({
    imports: [
        // ...
        DxChartModule
    ],
    // ...
})
Vue
App.vue
<template> 
    <DxChart ... >
        <DxExport
            :enabled="true"
            :formats="['PNG', 'JPEG']"
            file-name="exported_chart"
        />
    </DxChart>
</template>

<script>
import DxChart, {
    DxExport
} from 'devextreme-vue/chart';

export default {
    components: {
        DxChart,
        DxExport
    }
}
</script>
React
App.js
import React from 'react';
import Chart, {
    Export
} from 'devextreme-react/chart';

const exportFormats = ['PNG', 'JPEG'];

class App extends React.Component {
    render() {
        return (
            <Chart ... >
                <Export
                    enabled={true}
                    formats={exportFormats}
                    fileName="exported_chart"
                />
            </Chart>
        );
    }
}

export default App;

To support exporting and printing in Safari on MacOS, you need to set up a proxy on your server. For details, see the Set Up a Server-Side Proxy topic.

API

To export a widget using the API, call the exportTo(fileName, format) method passing the needed file name and format ("PNG", "PDF", "JPEG", "SVG" or "GIF") as the arguments. To print a widget, call the print() method. This command opens the browser's Print window.

jQuery
JavaScript
var chart = $("#chartContainer").dxChart("instance");
chart.exportTo('Exported Chart', 'PDF');
chart.print();
Angular
TypeScript
import { ..., ViewChild } from "@angular/core";
import { DxChartModule, DxChartComponent } from "devextreme-angular";
// ...
export class AppComponent {
    @ViewChild(DxChartComponent, { static: false }) chart: DxChartComponent;
    // Prior to Angular 8
    // @ViewChild(DxChartComponent) chart: DxChartComponent;
    exportChart () {
        this.chart.instance.exportTo('Exported Chart', 'PDF');
    };
    printChart () {
        this.chart.instance.print();
    };
}
@NgModule({
    imports: [
        // ...
        DxChartModule
    ],
    // ...
})
Vue
App.vue
<template> 
    <DxChart
        ref="chart"
        ... >
        <DxExport :enabled="true"/>
    </DxChart>
</template>

<script>
import DxChart, { DxExport } from 'devextreme-vue/chart';

export default {
    components: {
        DxChart,
        DxExport
    },
    methods: {
        exportChart() {
            this.$refs.chart.instance.exportTo('Exported Chart', 'PDF');
        },
        printChart() {
            this.$refs.chart.instance.print();
        }
    }
}
</script>
React
App.js
import React from 'react';
import Chart, { Export } from 'devextreme-react/chart';

class App extends React.Component {
    constructor(props) {
        super(props);
        this.chartRef = React.createRef();
    }

    render() {
        return (
            <Chart ref={this.chartRef} ... >
                <Export enabled={true}>
            </Chart>
        );
    }

    get chart() {
        return this.chartRef.current.instance;
    }

    exportChart() {
        this.chart.exportTo('Exported Chart', 'PDF');
    }

    printChart() {
        this.chart.print();
    }
}

export default App;

You can also export several widgets at once using their SVG markup. Gather the markup from all required widgets by calling the DevExpress.viz.getMarkup(widgetInstances) method, and then pass the markup to the DevExpress.viz.exportFromMarkup(markup, options) method.

jQuery
JavaScript
var chart1 = $("#chartContainer1").dxChart("instance");
var chart2 = $("#chartContainer2").dxChart("instance");
var chartMarkup = DevExpress.viz.getMarkup([chart1, chart2]);

DevExpress.viz.exportFromMarkup(chartMarkup, {
    height: 768,
    width: 1024,
    fileName: "Exported Charts",
    format: "PDF"
});
Angular
TypeScript
HTML
import { ..., ViewChild } from "@angular/core";
import { DxChartModule, DxChartComponent } from "devextreme-angular";
import exportMethods from "devextreme/viz/export";
// ...
export class AppComponent {
    @ViewChild('chartContainer1', { static: false }) chart1: DxChartComponent;
    @ViewChild('chartContainer2', { static: false }) chart2: DxChartComponent;
    // Prior to Angular 8
    // @ViewChild('chartContainer1') chart1: DxChartComponent;
    // @ViewChild('chartContainer2') chart2: DxChartComponent;
    exportSeveralCharts () {
        let chartMarkup = exportMethods.getMarkup([this.chart1.instance, this.chart2.instance]);
        exportMethods.exportFromMarkup(chartMarkup, {
            height: 768,
            width: 1024,
            fileName: "Exported Charts",
            format: "PDF"
        });
    };
}
@NgModule({
    imports: [
        // ...
        DxChartModule
    ],
    // ...
})
<dx-chart #chartContainer1 ... ></dx-chart>
<dx-chart #chartContainer2 ... ></dx-chart>

Events

DevExtreme data visualization widgets raise the following exporting-related events.

  • exporting
    Allows you to request exporting details or prevent exporting.

  • exported
    Allows you to notify an end user when exporting is completed.

  • fileSaving
    Allows you to access exported data in the BLOB format and/or prevent it from being saved in a file on the user's local storage.

You can handle these events with functions. If the handling functions are not going to be changed at runtime, assign them to the onExporting, onExported and onFileSaving options when you configure the widget.

jQuery
JavaScript
$(function() {
    $("#chartContainer").dxChart({
        // ...
        onExporting: function (e) {
            // Handler of the "exporting" event
        },
        onExported: function (e) {
            // Handler of the "exported" event
        },
        onFileSaving: function (e) {
            // Handler of the "fileSaving" event
        }
    });
});
Angular
HTML
TypeScript
<dx-chart ...
    (onExporting)="onExporting($event)"
    (onExported)="onExported($event)"
    (onFileSaving)="onFileSaving($event)">
</dx-chart>
import { DxChartModule } from "devextreme-angular";
// ...
export class AppComponent {
    onExporting (e) {
        // Handler of the "exporting" event
    };
    onExported (e) {
        // Handler of the "exported" event
    };
    onFileSaving (e) {
        // Handler of the "fileSaving" event
    }
}
@NgModule({
    imports: [
        // ...
        DxChartModule
    ],
    // ...
})
Vue
App.vue
<template> 
    <DxChart
        @exporting="onExporting"
        @exported="onExported"
        @file-saving="onFileSaving"
        >
        <DxExport :enabled="true"/>
    </DxChart>
</template>

<script>
import DxChart, {
    DxExport
} from 'devextreme-vue/chart';

export default {
    components: {
        DxChart,
        DxExport
    },
    methods: {
        onExporting(e) {},
        onExported(e) {},
        onFileSaving(e) {}
    }
}
</script>
React
App.js
import React from 'react';
import Chart, {
    Export
} from 'devextreme-react/chart';

class App extends React.Component {
    render() {
        return (
            <Chart
                onExporting={this.onExporting}
                onExported={this.onExported}
                onFileSaving={this.onFileSaving}
                >
                <Export enabled={true}/>
            </Chart>
        );
    }

    onExporting(e) {}
    onExported(e) {}
    onFileSaving(e) {}
}

export default App;

Otherwise, or if you need several handlers for a single event, subscribe to the exporting-related events using the on(eventName, eventHandler) method. This approach is more typical of jQuery.

JavaScript
var exportedHandler1 = function (e) {
    // First handler of the "exported" event
};

var exportedHandler2 = function (e) {
    // Second handler of the "exported" event
};

$("#chartContainer").dxChart("instance")
    .on("exported", exportedHandler1)
    .on("exported", exportedHandler2);
See Also

Set Up a Server-Side Proxy

If you need exporting and printing in browsers that do not provide an API for saving files (that is, in Safari on Mac OS), implement a server-side proxy that will stream the resulting file back to an end user in response to a POST request. The proxy implementation is different for each platform.

ASPx

C#
VB
using System;
using System.Web;

namespace ExportService {

    public class ExportHandler : IHttpHandler {
        public void ProcessRequest(HttpContext context) {
            if(context.Request.Form["contentType"] != null && 
               context.Request.Form["fileName"]    != null && 
               context.Request.Form["data"]        != null) {
                context.Response.Clear();
                context.Response.ContentType = context.Request.Form["contentType"].ToString();
                context.Response.Charset = "UTF-8";
                context.Response.Expires = 0;
                context.Response.AppendHeader("Content-transfer-encoding", "binary");
                context.Response.AppendHeader("Content-Disposition", 
                                              "attachment; filename=" + context.Request.Form["fileName"].ToString());
                context.Response.BinaryWrite(Convert.FromBase64String(context.Request.Form["data"].ToString()));
                context.Response.Flush();
                context.Response.End();
            }
        }
        public bool IsReusable {
            get { return false; }
        }
    }
}
Imports System
Imports System.Web

Namespace ExportService

    Public Class ExportHandler
        Implements IHttpHandler

        Public Sub ProcessRequest(ByVal context As HttpContext) Implements IHttpHandler.ProcessRequest
            If context.Request.Form("contentType") IsNot Nothing AndAlso
               context.Request.Form("fileName")    IsNot Nothing AndAlso
               context.Request.Form("data")        IsNot Nothing Then
                context.Response.Clear()
                context.Response.ContentType = context.Request.Form("contentType").ToString()
                context.Response.Charset = "UTF-8"
                context.Response.Expires = 0
                context.Response.AppendHeader("Content-transfer-encoding", "binary")
                context.Response.AppendHeader("Content-Disposition", "attachment; filename=" & context.Request.Form("fileName").ToString())
                context.Response.BinaryWrite(Convert.FromBase64String(context.Request.Form("data").ToString()))
                context.Response.Flush()
                context.Response.End()
            End If
        End Sub

        Public ReadOnly Property IsReusable() As Boolean Implements IHttpHandler.IsReusable
            Get
                Return False
            End Get
        End Property
    End Class

End Namespace

PHP 

<?php
    if(!empty($_POST["data"]) && !empty($_POST["contentType"]) && !empty($_POST["fileName"])) {
      header("Access-Control-Allow-Origin: *");
      header("Content-type: {$_POST['contentType']};\n");
      header("Content-Transfer-Encoding: binary");
      header("Content-length: ".strlen($_POST['data']).";\n");
      header("Content-disposition: attachment; filename=\"{$_POST['fileName']}\"");
      die(base64_decode($_POST["data"]));
    } 
?>

Usage

To notify the widget that it must export the file through a proxy, specify the export.proxyUrl option.