jsReport generates blank pdf

Ljuc_Kravec

Hi guys,

I have a problem with generating pdf report from ASP.NET Core app. I've followed this tutorial: https://jsreport.net/learn/dotnet-aspnetcore

Here is my code:

ExportController.cs

        [MiddlewareFilter(typeof(JsReportPipeline))]
        [Route("Export/ExportDataToPdf")]
        public async Task<IActionResult> ExportDataToPdf()
        {
            HttpContext.JsReportFeature().Recipe(Recipe.ChromePdf);
            HttpContext.JsReportFeature().OnAfterRender((r) => {
                using (var file = System.IO.File.Open("report.pdf", FileMode.Create))
                {
                    r.Content.CopyTo(file);
                }
                r.Content.Seek(0, SeekOrigin.Begin);
            });
            return View();

Startup.cs

  public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc()
        .AddSessionStateTempDataProvider();

            services.AddSession();

            services.AddMemoryCache();
            //services.AddDistributedMemoryCache();

            services.AddControllersWithViews()
                .AddNewtonsoftJson();

            services.AddJsReport(new LocalReporting()
                    .UseBinary(JsReportBinary.GetBinary())
                    .AsUtility()
                    .Create());


        }

Index.cshtml

   <input class="button .button-block pull-right" type="submit" value="Export" onclick="location.href=' @Url.Action("ExportDataToPdf", "Export")'" />

After returning a view from ExportDataToPdf() I get blank pdf document in the browser. Looks like content was not placed to the stream. Any ideas what am I doing wrong?
Thanks

jan_blaha

Could you please try this example? Does it work for you?
https://github.com/jsreport/jsreport-dotnet-example-webapp

I don't know what you have in the ExportDataToPdf view. Maybe there is a problem.
I could take a look if you would create a minimal public repo that shows the problem.

Ljuc_Kravec

Yes, your example is working.

I had wrong view attached to the ExportDataToPdf function (I thought that it creates stream from current opened view).
Now it's partially working, but chart is missing. Check out images bellow. Chart is produced through javascript library Google.Charts. In the html code is showing as svg image.

this is an app:

this is a pdf output:

Have you seen something similar to this issue?
I can't post entire code to the repo, because I don't own rights.

Thank you.

jan_blaha

The reason can be that the pdf is being printed before the chart finished its rendering.
This can be solved by delaying printing until you have everything loaded and rendered.
Please see the documentation and example
https://jsreport.net/learn/chrome-pdf#printing-triggers
https://playground.jsreport.net/w/admin/O3R9I~xl