Exporting grid in server in Vue Grid component

23 Dec 202312 minutes to read

The Grid have an option to export the data to PDF in server side using Grid server export library.

Server dependencies

The Server side export functionality is shipped in the Syncfusion.EJ2.GridExport package, which is available in Essential Studio and nuget.org.The following list of dependencies is required for Grid server side PDF exporting action.

  • Syncfusion.EJ2
  • Syncfusion.EJ2.GridExport

Server configuration

The following code snippet shows server configuration using ASP.NET Core Controller Action.

To Export the Grid in server side, You need to call the serverPdfExport method for passing the Grid properties to server exporting action.

public ActionResult PdfExport([FromForm] string gridModel)
{
    GridPdfExport exp = new GridPdfExport();
    Grid gridProperty = ConvertGridObject(gridModel);
    return exp.PdfExport<OrdersDetails>(gridProperty, OrdersDetails.GetAllRecords());
}

private Grid ConvertGridObject(string gridProperty)
{
    Grid GridModel = (Grid)Newtonsoft.Json.JsonConvert.DeserializeObject(gridProperty, typeof(Grid));
    GridColumnModel cols = (GridColumnModel)Newtonsoft.Json.JsonConvert.DeserializeObject(gridProperty, typeof(GridColumnModel));
    GridModel.Columns = cols.columns;
    return GridModel;
}

public class GridColumnModel
{
    public List<GridColumn> columns { get; set; }
}
<template>
    <div id="app">
        <ejs-grid ref='grid' id='Grid' :dataSource='data' :toolbar='toolbarOptions' height='272px' :toolbarClick='toolbarClick'>
            <e-columns>
                <e-column field='OrderID' headerText='Order ID' textAlign='Right' width=120></e-column>
                <e-column field='CustomerID' headerText='Customer ID' width=150></e-column>
                <e-column field='ShipCity' headerText='Ship City' width=150></e-column>
                <e-column field='ShipName' headerText='Ship Name' width=150></e-column>
            </e-columns>
        </ejs-grid>
    </div>
</template>
<script>
import Vue from "vue";
import { GridPlugin, Toolbar } from "@syncfusion/ej2-vue-grids";
import { data } from './datasource.js';

Vue.use(GridPlugin);

export default {
  data() {
    return {
      data: data,
      toolbarOptions: ['PdfExport']
    };
  },
  methods: {
      toolbarClick: function(args) {
        if (args.item.id === 'Grid_pdfexport') { // 'Grid_pdfexport' -> Grid component id + _ + toolbar item name
            this.$refs.grid.serverPdfExport('Home/PdfExport');
        }
    }
  },
  provide: {
    grid: [Toolbar]
  }
}
</script>
<style>
 @import "../node_modules/@syncfusion/ej2-vue-grids/styles/material.css";
</style>

Note: Refer to the GitHub sample for quick implementation and testing from here.

Export grid as memory stream

The Grid offers an option to export the data as a memory stream instead of downloading it as a file in the browser. To obtain the memory stream of the exported grid, set the AsMemoryStream parameter to true in the PdfExport method.

The following code demonstrates how to get the memory stream of exported grid.

public object PdfExport(string gridModel)
{
    GridPdfExport exp = new GridPdfExport();
    Grid gridProperty = ConvertGridObject(gridModel);
    // pass third parameter as true to get the Memory Stream of exported grid data
    return (MemoryStream)exp.PdfExport<OrdersDetails>(gridProperty, OrdersDetails.GetAllRecords(), true);
}

Merge grid’s memory stream

The Essential PDF library is used to merge multiple memory streams into a single stream. To learn more about the merge option, please refer to this documentation.

You can merge a memory stream, a file stream, and a local file with the Grid’s memory stream in the following ways:

Merging with an existing memory stream

If you already have a memory stream, you can directly use it to merge with the Grid’s memory stream.

In the following code, the Merge method of the PdfDocumentBase class is used to merge the grid’s memory stream with an existing memory stream.

using Syncfusion.Pdf;

public MemoryStream ms1; // defines existing memory stream

public object PdfExport(string gridModel)
{
    GridPdfExport exp = new GridPdfExport();
    Grid gridProperty = ConvertGridObject(gridModel);
    // get the memory stream of exported grid data
    MemoryStream ms2 = (MemoryStream)exp.PdfExport<OrdersDetails>(gridProperty, OrdersDetails.GetAllRecords(), true);
    //Creates a PDF document.
    PdfDocument finalDoc = new PdfDocument();
    //Creates a PDF stream for merging. ms1 and ms2 represents the existing stream and grid's stream.
    Stream[] streams = { ms1, ms2 };
    //Merges PDFDocument.
    PdfDocumentBase.Merge(finalDoc, streams);
    //Save the document into stream.
    MemoryStream ms3 = new MemoryStream();
    finalDoc.Save(ms3);    
    ms3.Position = 0;
    //Close the document.
    finalDoc.Close(true);
    //Dispose the streams.
    ms1.Dispose();
    ms2.Dispose();
    return ms3;
}

Merging with an existing file stream

If you already have a file stream, you can directly use it to merge with the Grid’s memory stream. In the following code, the existing file stream is merged with the Grid’s memory stream.

using Syncfusion.Pdf;

public FileStream fs1; // defines existing file stream

public ActionResult PdfExport(string gridModel)
{
    GridPdfExport exp = new GridPdfExport();
    Grid gridProperty = ConvertGridObject(gridModel);
    MemoryStream ms1 = (MemoryStream)exp.PdfExport<OrdersDetails>(gridProperty, OrdersDetails.GetAllRecords(), true);
    PdfDocument finalDoc = new PdfDocument();
    //fs1 and ms1 represents the existing stream and grid's stream.
    Stream[] streams = { fs1, ms1 };
    PdfDocumentBase.Merge(finalDoc, streams);
    MemoryStream ms3 = new MemoryStream();
    finalDoc.Save(ms3);    
    ms3.Position = 0;
    return ms3;
}

Merging with a local file

To merge a local file with the Grid’s memory stream, you need to convert it into a file stream before merging. In the following code, the existing local file is merged with the Grid’s memory stream.

using Syncfusion.Pdf;

// get the file stream of local file
public FileStream fs1 = new FileStream("D:/PdfDoc.pdf", FileMode.Open, FileAccess.Read); // PdfDoc.pdf is a local file which is located in local disk D.

public ActionResult PdfExport(string gridModel)
{
    GridPdfExport exp = new GridPdfExport();
    Grid gridProperty = ConvertGridObject(gridModel);
    MemoryStream ms1 = (MemoryStream)exp.PdfExport<OrdersDetails>(gridProperty, OrdersDetails.GetAllRecords(), true);
    PdfDocument finalDoc = new PdfDocument();
    //fs1 and ms1 represents the local file's stream and grid's stream.
    Stream[] streams = { fs1, ms1 };
    PdfDocumentBase.Merge(finalDoc, streams);
    MemoryStream ms3 = new MemoryStream();
    finalDoc.Save(ms3);    
    ms3.Position = 0;
    return ms3;
}

Downloading the merged memory stream

You can download the merged memory stream by converting it into a FileStreamResult. In the following code, the merged memory stream is downloaded to the browser.

using Syncfusion.Pdf;

public ActionResult PdfExport(string gridModel)
{
    PdfDocument finalDoc = new PdfDocument();
    //ms1 and ms2 represents the streams needs to merge.
    Stream[] streams = { ms1, ms2 };
    PdfDocumentBase.Merge(finalDoc, streams);
    MemoryStream ms3 = new MemoryStream();
    finalDoc.Save(ms3);
    ms3.Position = 0;
    // Save the MemoryStream into FileStreamResult
    FileStreamResult fileStreamResult = new FileStreamResult(ms3, "application/pdf");
    fileStreamResult.FileDownloadName = "Export.pdf";
    //Close the document.
    finalDoc.Close(true);
    //Dispose the streams.
    ms1.Dispose();
    ms2.Dispose();
    // return the file
    return fileStreamResult;
}

Rotate a header text to a certain degree in the exported grid on the server side

The Grid has support to customize the column header styles such as changing text orientation, the font color, and so on in the exported PDF file. To achieve this requirement, define the BeginCellLayout event of the PdfExportProperties with an event handler to perform the required action.

The PdfHeaderQueryCellInfoEvent will be triggered when creating a column header for the pdf document to be exported. Collect the column header details in this event and handle the custom in the BeginCellLayout event handler.

In the following demo, the DrawString method from the Graphics is used to rotate the header text of the column header inside the BeginCellLayout event handler.

A PDF exporting is not supported to rotate the column header on the client side.

public ActionResult PdfExport(string gridModel)
{
    GridPdfExport exp = new GridPdfExport();
    Grid gridProperty = ConvertGridObject(gridModel);
    gridProperty.ServerPdfHeaderQueryCellInfo = PdfHeaderQueryCellInfo;
    PdfGrid grid = new PdfGrid();
    PdfExportProperties pdfExportProperties = new PdfExportProperties();
    pdfExportProperties.IsRepeatHeader = true;
    pdfExportProperties.BeginCellLayout = new PdfGridBeginCellLayoutEventHandler(BeginCellEvent);
    gridProperty.ServerPdfQueryCellInfo = PdfQueryCellInfo;
    IEnumerable data = Utils.DataTableToJson(dt);
    var result = exp.PdfExport<dynamic>(gridProperty, data, pdfExportProperties);
    return result;
}
public void BeginCellEvent(object sender, PdfGridBeginCellLayoutEventArgs args)
{
    PdfGrid grid = (PdfGrid)sender;
    var brush = new PdfSolidBrush(new PdfColor(Color.DimGray));
    args.Graphics.Save();
    args.Graphics.TranslateTransform(args.Bounds.X + 50, args.Bounds.Height + 40); // give the value for bounds x and Y by the user
    args.Graphics.RotateTransform(-60);   // give the rotate degree value by the user
    // Draw the text at particular bounds.
    args.Graphics.DrawString(headerValues[args.CellIndex], new PdfStandardFont(PdfFontFamily.Helvetica, 10), brush, new PointF(0, 0));
    if (args.IsHeaderRow)
        {
            grid.Headers[0].Cells[args.CellIndex].Value = string.Empty;
        }
    args.Graphics.Restore();
}
private void PdfHeaderQueryCellInfo(object pdf)
{
    ServerPdfHeaderQueryCellInfoEventArgs name = (ServerPdfHeaderQueryCellInfoEventArgs)pdf;
    PdfGrid grid = new PdfGrid();
    headerValues.Add(name.Column.HeaderText);
    var longestString = headerValues.Where(s => s.Length == headerValues.Max(m => m.Length)).First();
    PdfFont font = new PdfStandardFont(PdfFontFamily.Helvetica, 6);
    SizeF size = font.MeasureString(longestString);
    name.Headers[0].Height = size.Width * 2;
}

Limitations

  • The export feature for detail and caption templates is not supported in server-side exporting.
  • Multiple grids exporting feature is not supported with server side exporting.