Working with JavaScript

23 Jul 202612 minutes to read

A JavaScript action allows execution of JavaScript code embedded in a PDF document. Syncfusion® PDF supports adding JavaScript actions to a PDF document in the following ways:

  • Document-level JavaScript action
  • JavaScript action on form fields
  • JavaScript in 3D annotations

Note: PDF JavaScript uses the Acrobat JavaScript API (such as app.alert, this.print, and host.getURL) rather than the standard browser JavaScript API. Refer to the Acrobat JavaScript API Reference for the complete list of supported objects and methods.

Document-level JavaScript action

You can add a JavaScript action to the PDF document by using the PdfJavaScriptAction class and assigning it to the Actions property of the PdfDocument class. The following code example shows how to add an AfterOpen action that displays an alert when the document is opened.

using System.IO;
using Syncfusion.Pdf;
using Syncfusion.Pdf.Interactive;

//Create a new document.
PdfDocument document = new PdfDocument();
//Add a page.
PdfPage page = document.Pages.Add();

//Create a JavaScript action.
PdfJavaScriptAction scriptAction = new PdfJavaScriptAction("app.alert(\"Hello World!!!\")");
//Add the JavaScript action to the document.
document.Actions.AfterOpen = scriptAction;

//Save and close the PDF document.
using (FileStream outputStream = new FileStream("Output.pdf", FileMode.Create, FileAccess.Write))
{
    document.Save(outputStream);
}
document.Close(true);
using Syncfusion.Pdf;
using Syncfusion.Pdf.Interactive;

//Create a new document.
PdfDocument document = new PdfDocument();
//Add a page.
PdfPage page = document.Pages.Add();

//Create a JavaScript action.
PdfJavaScriptAction scriptAction = new PdfJavaScriptAction("app.alert(\"Hello World!!!\")");
//Add the JavaScript action to the document.
document.Actions.AfterOpen = scriptAction;

//Save and close the PDF document.
document.Save("Output.pdf");
document.Close(true);
Imports Syncfusion.Pdf
Imports Syncfusion.Pdf.Interactive

'Create a new document.
Dim document As New PdfDocument()
'Add a page.
Dim page As PdfPage = document.Pages.Add()

'Create a JavaScript action.
Dim scriptAction As New PdfJavaScriptAction("app.alert(""Hello World!!!"")")
'Add the JavaScript action to the document.
document.Actions.AfterOpen = scriptAction

'Save and close the PDF document.
document.Save("Output.pdf")
document.Close(True)

You can download a complete working sample from GitHub.

Note: The PdfDocumentActions class also exposes the BeforeClose and BeforeSave properties, which allow you to trigger JavaScript code before the document is closed or saved.

JavaScript action on form fields

You can add JavaScript actions to form fields using the PdfJavaScriptAction class. The PdfFieldActions class is used to assign actions to a form field.

The following code example shows how to attach a MouseDown JavaScript action to a button field.

using System.IO;
using Syncfusion.Drawing;
using Syncfusion.Pdf;
using Syncfusion.Pdf.Graphics;
using Syncfusion.Pdf.Interactive;

//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Create a new page.
PdfPage page = document.Pages.Add();

//Create a new button field.
PdfButtonField submitButton = new PdfButtonField(page, "submitButton");
submitButton.Bounds = new RectangleF(25, 160, 100, 20);
submitButton.Text = "Apply";
submitButton.BackColor = new PdfColor(181, 191, 203);

//Create a JavaScript action.
PdfJavaScriptAction scriptAction = new PdfJavaScriptAction("app.alert(\"You are looking at Form field action of PDF\")");
//Set the JavaScript action to the button.
submitButton.Actions.MouseDown = scriptAction;

//Add the button to the new document.
document.Form.Fields.Add(submitButton);

//Save and close the PDF document.
using (FileStream outputStream = new FileStream("Output.pdf", FileMode.Create, FileAccess.Write))
{
    document.Save(outputStream);
}
document.Close(true);
using System.Drawing;
using Syncfusion.Pdf;
using Syncfusion.Pdf.Graphics;
using Syncfusion.Pdf.Interactive;

//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Create a new page.
PdfPage page = document.Pages.Add();

//Create a new button field.
PdfButtonField submitButton = new PdfButtonField(page, "submitButton");
submitButton.Bounds = new RectangleF(25, 160, 100, 20);
submitButton.Text = "Apply";
submitButton.BackColor = new PdfColor(181, 191, 203);

//Create a JavaScript action.
PdfJavaScriptAction scriptAction = new PdfJavaScriptAction("app.alert(\"You are looking at Form field action of PDF\")");
//Set the JavaScript action to the button.
submitButton.Actions.MouseDown = scriptAction;

//Add the button to the new document.
document.Form.Fields.Add(submitButton);

//Save and close the document.
document.Save("Output.pdf");
document.Close(true);
Imports System.Drawing
Imports Syncfusion.Pdf
Imports Syncfusion.Pdf.Interactive
Imports Syncfusion.Pdf.Graphics

'Create a new PDF document.
Dim document As New PdfDocument()
'Create a new page.
Dim page As PdfPage = document.Pages.Add()

'Create a new button field.
Dim submitButton As New PdfButtonField(page, "submitButton")
submitButton.Bounds = New RectangleF(25, 160, 100, 20)
submitButton.Text = "Apply"
submitButton.BackColor = New PdfColor(181, 191, 203)

'Create a JavaScript action.
Dim scriptAction As New PdfJavaScriptAction("app.alert(""You are looking at Form field action of PDF"")")
'Set the JavaScript action to the button.
submitButton.Actions.MouseDown = scriptAction

'Add the button to the new document.
document.Form.Fields.Add(submitButton)

'Save and close the document.
document.Save("Output.pdf")
document.Close(True)

You can download a complete working sample from GitHub.

JavaScript in 3D Annotation

The 3D Annotations are used to represent 3D artworks in a PDF document. You can add a JavaScript code to 3D annotation using the OnInstantiate property in Pdf3DAnnotation instance. The JavaScript script is executed when the 3D artwork is instantiated. The following code snippet illustrate this.

using System.IO;
using Syncfusion.Drawing;
using Syncfusion.Pdf;
using Syncfusion.Pdf.Interactive;

//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Create a new page.
PdfPage page = document.Pages.Add();

//Load the 3D annotation stream.
FileStream inputStream = new FileStream("3DAnnotation.U3D", FileMode.Open, FileAccess.Read);
//Create a new PDF 3D annotation.
Pdf3DAnnotation pdf3dAnnotation = new Pdf3DAnnotation(new RectangleF(10, 50, 300, 150), inputStream);
//Assign a JavaScript script.
pdf3dAnnotation.OnInstantiate = "host.getURL(\"http://www.google.com\")";
//Handle the activation of the 3D annotation.
Pdf3DActivation activation = new Pdf3DActivation();
activation.ActivationMode = Pdf3DActivationMode.ExplicitActivation;
activation.ShowToolbar = true;
pdf3dAnnotation.Activation = activation;
//Add the annotation to the page.
page.Annotations.Add(pdf3dAnnotation);

//Save and close the PDF document.
using (FileStream outputStream = new FileStream("Output.pdf", FileMode.Create, FileAccess.Write))
{
    document.Save(outputStream);
}
document.Close(true);
using System.Drawing;
using Syncfusion.Pdf;
using Syncfusion.Pdf.Interactive;

//Create a new PDF document.
PdfDocument document = new PdfDocument();
//Create a new page.
PdfPage page = document.Pages.Add();

//Create a new PDF 3D annotation.
Pdf3DAnnotation pdf3dAnnotation = new Pdf3DAnnotation(new RectangleF(10, 50, 300, 150), "Input.u3d");
//Assign a JavaScript script.
pdf3dAnnotation.OnInstantiate = "host.getURL(\"http://www.google.com\")";
//Handle the activation of the 3D annotation.
Pdf3DActivation activation = new Pdf3DActivation();
activation.ActivationMode = Pdf3DActivationMode.ExplicitActivation;
activation.ShowToolbar = true;
pdf3dAnnotation.Activation = activation;
//Add the annotation to the page.
page.Annotations.Add(pdf3dAnnotation);

//Save and close the document.
document.Save("Output.pdf");
document.Close(true);
Imports System.Drawing
Imports Syncfusion.Pdf
Imports Syncfusion.Pdf.Interactive

'Create a new PDF document.
Dim document As New PdfDocument()
'Create a new page.
Dim page As PdfPage = document.Pages.Add()

'Create a new PDF 3D annotation.
Dim pdf3dAnnotation As New Pdf3DAnnotation(New RectangleF(10, 50, 300, 150), "Input.u3d")
'Assign a JavaScript script.
pdf3dAnnotation.OnInstantiate = "host.getURL(""http://www.google.com"")"
'Handle the activation of the 3D annotation.
Dim activation As New Pdf3DActivation()
activation.ActivationMode = Pdf3DActivationMode.ExplicitActivation
activation.ShowToolbar = True
pdf3dAnnotation.Activation = activation
'Add the annotation to the page.
page.Annotations.Add(pdf3dAnnotation)

'Save and close the document.
document.Save("Output.pdf")
document.Close(True)

You can download a complete working sample from GitHub.

Note: 3D annotations require a U3D-formatted file as input. The U3D file must be available in the application directory or supplied through a stream. To view 3D content, the PDF reader must support the PDF 3D specification; the standard Acrobat Reader provides this support.

Add/Modify JavaScript actions to the PDF

Add or modify the JavaScript action in a PdfLoadedDocument. The below code example shows how to add/modify JavaScript code using PdfJavaScriptAction class to an existing PDF document.

// PDF does not support JavaScript actions in C#/.NET cross-platform environments.
using System.Drawing;
using Syncfusion.Pdf;
using Syncfusion.Pdf.Interactive;

//Load an existing PDF document.
PdfLoadedDocument loadedDocument = new PdfLoadedDocument("Input.pdf");

//Change the javascript action in a pdf document.
loadedDocument.Actions.AfterOpen= new PdfJavaScriptAction("app.alert(\"Modified Script!\")");

//Save the document.
loadedDocument.Save("Output.pdf");
//Close the document.
loadedDocument.Close(true);
Imports System.Drawing
Imports Syncfusion.Pdf
Imports Syncfusion.Pdf.Interactive

'Load the PDF document.
Dim loadedDocument As PdfLoadedDocument = New PdfLoadedDocument("Input.pdf")
 
'Change the javascript Action in a pdf document.
loadedDocument.Actions.AfterOpen = new PdfJavaScriptAction("app.alert(\"Modified Script!\")")

'Save the document.
loadedDocument.Save("Output.pdf")

'Close the document.
loadedDocument.Close(True)

You can download a complete working sample from GitHub.

Types of JavaScript actions

The pdf will generate trigger with the javascript actions in the following places.

Action Type Description
document.Actions.AfterOpen A JavaScript action will be performed after opening the document
document.Actions.BeforeClose A JavaScript action will be performed before closing the document
document.Actions.AfterSave A JavaScript action will be performed after saving the document
document.Actions.BeforeSave A JavaScript action will be performed before saving the document
document.Actions.AfterPrint A JavaScript action will be performed after printing the document
document.Actions.BeforePrint A JavaScript action will be performed before printing the document

Types of Mouseover actions

The pdf will generate trigger with the javascript actions on the form fields in the places listed below.

Action Type Description
submitButton.Actions.MouseDown Gets or sets the action to be performed when the mouse button is pressed inside the annotation’s active area.
submitButton.Actions.MouseUp Gets or sets the action to be performed when the mouse button is released inside the annotation’s active area.
submitButton.Actions.MouseEnter Gets or sets the action to be performed when the cursor enters the annotation’s active area.
submitButton.Actions.MouseLeave Gets or sets the action to be performed when the cursor exits the annotation’s active area.
submitButton.Actions.GotFocus Gets or sets the action to be performed when the annotation receives the input focus.
submitButton.Actions.LostFocus Gets or sets the action to be performed when the annotation loses the input focus.