DevExtreme React - 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 IE9 and 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.
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
$(function() { $("#chartContainer").dxChart({ // ... export: { enabled: true, printingEnabled: false } }); });
Angular
<dx-chart ... > <dxo-export [enabled]="true" [printingEnabled]="false"> </dxo-export> </dx-chart>
import { DxChartModule } from 'devextreme-angular'; // ... export class AppComponent { // ... } @NgModule({ imports: [ // ... DxChartModule ], // ... })
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
$(function() { $("#chartContainer").dxChart({ // ... export: { enabled: true, formats: ["PNG", "JPEG"], fileName: "exported_chart" } }); });
Angular
<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 ], // ... })
To support exporting and printing in IE9 and 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
var chart = $("#chartContainer").dxChart("instance"); chart.exportTo('Exported Chart', 'PDF'); chart.print();
Angular
import { ..., ViewChild } from '@angular/core'; import { DxChartModule, DxChartComponent } from 'devextreme-angular'; // ... export class AppComponent { @ViewChild(DxChartComponent) chart: DxChartComponent; exportChart () { this.chart.instance.exportTo('Exported Chart', 'PDF'); }; printChart () { this.chart.instance.print(); }; } @NgModule({ imports: [ // ... DxChartModule ], // ... })
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
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
import { ..., ViewChild } from '@angular/core'; import { DxChartModule, DxChartComponent } from 'devextreme-angular'; import exportMethods from 'devextreme/viz/export'; // ... export class AppComponent { @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
$(function() { $("#chartContainer").dxChart({ // ... onExporting: function (e) { // Handler of the "exporting" event }, onExported: function (e) { // Handler of the "exported" event }, onFileSaving: function (e) { // Handler of the "fileSaving" event } }); });
Angular
<dx-chart ... (onExporting)="onExporting($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 ], // ... })
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.
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
- Handle Events: jQuery | Angular | AngularJS | Knockout | ASP.NET MVC
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 IE9 and 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
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.
If you have technical questions, please create a support ticket in the DevExpress Support Center.