The Form Editor in DsPdfViewer allows you to edit, design, fill and submit PDF forms. You can create new forms or modify existing ones by adding or removing different types of form fields and setting or modifying form field's properties like Name, ReadOnly, Max Length, Value, Bounds, Border etc.

Along with the Form editor's toolbar, you can access all the form fields and various other options directly through the the main toolbar. It provides Form tools button which displays various form field buttons like text field, password field, radio button, checkbox etc. As can be observed, the 'Undo, Redo and Delete' and Redact options are also available in the quick editing toolbar.

You can also configure which tools should be displayed in the quick editing toolbar of Form tools by using the secondToolbarLayout property. Also, you can use Page tools to add a new blank document, insert a blank page, delete current page and perform undo or redo operations. To know more, refer Annotation Editor.

Alternatively, you can access all the form fields through the Form editor's toolbar which opens on clicking the Form editor button in the side panel. The below GIF shows a PDF form in DsPdfViewer in which a text field is added using the Form Editor:

The different toolbar buttons in the Form Editor are described as below:

Name	Toolbar Icons	Description
Select		Selects a form field added on PDF
Text		Adds a text field on PDF
Password		Adds a password field on PDF
Text Area		Adds a text area field to add long text on PDF
Checkbox		Adds a check box on PDF
RadioButton		Adds a radio button on PDF
PushButton		Adds a push button on PDF
Combobox		Adds a combo box on PDF
Listbox		Adds a list box on PDF
Comb-Text Field		Adds a comb-text field to add text in equally spaced positions on PDF
Submit Form Button		Adds a submit form button on PDF
Reset Form Button		Adds a reset form button on PDF
Delete Form ButtonCheckbox and Radio Button		Deletes the form field

Apart from the different types of form fields described above, DsPdfViewer also provides some general editing features while working with PDF documents. They are explained as below:

Toolbar Icons	Description
	Undo changes
	Redo changes
	Saves the modified document on client
	Saves the modified document as images on client
	Creates a new blank document
	Inserts a blank page
	Deletes current page
	Reorders and reorganizes the pages in a PDF document. For more information, see PDF Organizer.

You can also insert a blank page in a PDF document and set its size by using the newPage method. Alternatively, you can only set the size of an existing page using setPageSize method. To know more, refer Annotation Editor.

Property Panel of Form Editor

When you click the Form Editor icon in the left vertical panel, the Property panel of the Form Editor becomes visible. The Property panel displays the list of all the form fields page-wise in your document.

It also allows you to set or modify properties of any form field in the document like its text, border, location etc. For eg. The image below shows the properties of a text field in the Property panel.

Enable Form Editor in DsPdfViewer

The Form Editor is displayed by default in DsPdfViewer, by enabling the FormEditorPanel in the viewer using code:

<script>
    var viewer = new DsPdfViewer("#host", { supportApi: 'SupportApi/DsPdfViewer' });
    viewer.addDefaultPanels();
    viewer.addFormEditorPanel();
    viewer.beforeUnloadConfirmation = true;
    viewer.open("Home/GetPdf");
</script>

To customize the form fields in DsPdfViewer, add the following lines of code in the class file where you load the PDF in the Viewer:

public static DsPdfViewerSupportApiDemo.Models.PdfViewerOptions PdfViewerOptions
        {
            get => new DsPdfViewerSupportApiDemo.Models.PdfViewerOptions(
                DsPdfViewerSupportApiDemo.Models.PdfViewerOptions.Options.FormEditorPanel |
                DsPdfViewerSupportApiDemo.Models.PdfViewerOptions.Options.ActivateFormEditor,
                formEditorTools: new string[] { "edit-select-field", "$split", "edit-widget-tx-field", "edit-widget-tx-text-area", "$split", "edit-erase-field", "$split", "edit-undo", "edit-redo", "save" });
        }

Create a PDF form using Form Editor

Follow the below steps to create a 'Customer Detail' PDF form using the Form Editor in DsPdfViewer:

1. Configure the DsPdfViewer for editing PDF documents and run the application.
2. Load a PDF document containing static text corresponding to which you want to add form fields.
3. Open the Form Editor using the last icon on the left vertical panel.
4. Add text fields, text area and radio buttons to your form by using form editor tools.
5. Set properties of form fields from the Property panel like location, border etc.
6. Add a combo box which displays various drop down options when clicked (as shown below).
7. Close the Form Editor and go back to View mode.

A Customer Detail PDF form is created successfully. You can view the list of all the form fields in the property panel of Form Editor. 

Tab Order of Form Fields

The tab order of form fields can be viewed (if already set in a PDF document) or set in the property panel of Form Editor. It helps to navigate through the form fields using the tab key. This is specially useful when filling long forms. DsPdfViewer allows you to set any of the tab order settings specified in the PDF specification 2.0, namely:

• Row
• Column
• Structure
• Not Specified

In view mode, only the 'Row', 'Column' and 'Not Specified' (follows the order of annotations in the page) tab orders are supported.

You can also set the tab order in a PDF document using DsPdf API. To know more, refer Forms.

Orientation of Form Field

When a form field is placed on a rotated PDF page, it is added in its original position and does not adjust to the new orientation by itself. To enable rotation of form fields placed on a PDF page, DsPdfViewer provides Orientation property which lets you set the field orientation in multiples of 90 degrees.

Below sample code shows how to set orientation of the form fields in a PDF document.

// Change orientation to 180 degrees
fld1.orientation = 180;