SelectPdf for .NET - Start Conversion from Javascript - VB.NET / ASP.NET Sample

This sample shows how to manually start the html to pdf conversion of the SelectPdf Library for .NET using a Javascript call.

SelectPdf exposes a global Javascript variable called selectpdf in the page that is being converted. Using this variable you can check if the javascript code is executed inside the converter (check if typeof(selectpdf) == "object"). The converter version can also be checked using selectpdf.version.

The most important feature of the Javascript interface is the possibility to manually start the page conversion to pdf with a javascript call. To do that, you must:
1. Set converter.Options.StartupMode = StartupMode.Manual
2. Call selectpdf.start() from javascript

- If converter.Options.StartupMode is set to StartupMode.Manual and selectpdf.start() is not called from javascript, the conversion will timeout.
- If converter.Options.StartupMode is set to the default value StartupMode.Automatic, the conversion will start without waiting for any javascript calls.

Below it's the link to a test page that waits for 3 seconds after it loads and then calls the javascript conversion method. Converting it in StartupMode.Manual mode will display the time elapsed. Converting it in StartupMode.Automatic mode will not show that 3 seconds time interval.

Test page


Conversion start mode:


Sample Code Vb.Net

Imports System.Collections.Generic
Imports System.Linq
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports SelectPdf

Namespace SelectPdf.Samples
    Partial Public Class convert_from_js
        Inherits System.Web.UI.Page

        Protected Sub Page_Load(sender As Object, e As EventArgs)
            If Not IsPostBack Then
                Dim url As String = Page.ResolveUrl("~/files/js-conversion.html")
                TxtUrl.Text = (New Uri(Request.Url, url)).AbsoluteUri
                LnkTest.NavigateUrl = url
            End If
        End Sub

        Protected Sub BtnCreatePdf_Click(sender As Object, e As EventArgs)
            ' instantiate a html to pdf converter object
            Dim converter As New HtmlToPdf()

            ' set startup mode
            converter.Options.StartupMode = DirectCast( _
                [Enum].Parse(GetType(HtmlToPdfStartupMode), DdlStartupMode.SelectedValue, True),  _

            ' set timeout
            Dim timeout As Integer = 10
                timeout = Convert.ToInt32(TxtTimeout.Text)
            End Try
            converter.Options.MaxPageLoadTime = timeout

            ' create a new pdf document converting an url
            Dim doc As PdfDocument = converter.ConvertUrl(TxtUrl.Text)

            ' save pdf document
            doc.Save(Response, False, "Sample.pdf")

            ' close pdf document
        End Sub
    End Class
End Namespace