How to: Switch between a mail merge template and the result document

• Nov 12, 2020

JS

var commandId = "MailMergeSwitch";
var showMailMergeResult = false;
var templateDocument = null;
var format = DevExpress.RichEdit.DocumentFormat.OpenXml;

var newDataSource = [
    { firstName: "Alex", birthYear: 1991 },
    { firstName: "Joe", birthYear: 1990 },
    { firstName: "Bob", birthYear: 1995 }
];
var showTemplateDocument = function() {
    showMailMergeResult = !showMailMergeResult;
    richEdit.openDocument(templateDocument, "TemplateDocument", format);
};
var showResultDocument = function() {
    richEdit.loadingPanel.show();
    richEdit.exportToBase64(function(documentAsBase64) {
        templateDocument = documentAsBase64;
        richEdit.mailMerge(function (mergedDocument) {
          var reader = new FileReader();
          reader.onloadend = function () {
            showMailMergeResult = !showMailMergeResult;
            richEdit.openDocument(reader.result, "MergedDocument", format);
          };
          reader.readAsDataURL(mergedDocument);
        }, DevExpress.RichEdit.MergeMode.NewParagraph, format);
    });
};

richEdit.events.customCommandExecuted.addHandler(function(s, e) {
    if (e.commandName == commandId)
        if (showMailMergeResult)
            showTemplateDocument();
        else 
            showResultDocument();
});

richEdit.newDocument();
richEdit.document.insertText(richEdit.document.length, 'You can change template as you want.');
richEdit.document.insertParagraph(richEdit.document.length);
richEdit.document.insertText(richEdit.document.length, 'FirstName: ');
richEdit.document.fields.createMergeField(richEdit.document.length, "firstName").update();
richEdit.mailMergeOptions.setDataSource(newDataSource);

richEdit.documentName = "TemplateDocument";

richEdit.updateRibbon(function(ribbon) {
    if (!ribbon.getTab(DevExpress.RichEdit.RibbonTabType.MailMerge).getItem(commandId))
        ribbon.getTab(DevExpress.RichEdit.RibbonTabType.MailMerge)
            .insertItem(new DevExpress.RichEdit.RibbonButtonItem(commandId, "Switch document"), 0);
    ribbon.activeTabIndex = DevExpress.RichEdit.RibbonTabType.MailMerge;
});