pdf-lib › PDFButton

Represents a button field of a PDFForm.

PDFButton fields are interactive controls that users can click with their mouse. This type of PDFField is not stateful. The purpose of a button is to perform an action when the user clicks on it, such as opening a print modal or resetting the form. Buttons are typically rectangular in shape and have a text label describing the action that they perform when clicked.

Hierarchy

• PDFField

  ↳ PDFButton

Index

Properties

• acroField
• doc
• ref

Methods

• addToPage
• defaultUpdateAppearances
• disableExporting
• disableReadOnly
• disableRequired
• enableExporting
• enableReadOnly
• enableRequired
• getName
• isExported
• isReadOnly
• isRequired
• needsAppearancesUpdate
• setFontSize
• setImage
• updateAppearances
• of

Properties

acroField

• acroField: PDFAcroPushButton

Overrides PDFField.acroField

Defined in api/form/PDFButton.ts:54

The low-level PDFAcroPushButton wrapped by this button.

doc

• doc: PDFDocument

Inherited from PDFField.doc

Defined in api/form/PDFField.ts:92

The document to which this field belongs.

ref

• ref: PDFRef

Inherited from PDFField.ref

Defined in api/form/PDFField.ts:89

The unique reference assigned to this field within the document.

Methods

addToPage

▸ addToPage(text: string, page: PDFPage, options?: FieldAppearanceOptions): void

Defined in api/form/PDFButton.ts:149

Show this button on the specified page with the given text. For example:

const ubuntuFont = await pdfDoc.embedFont(ubuntuFontBytes)
const page = pdfDoc.addPage()

const form = pdfDoc.getForm()
const button = form.createButton('some.button.field')

button.addToPage('Do Stuff', page, {
  x: 50,
  y: 75,
  width: 200,
  height: 100,
  textColor: rgb(1, 0, 0),
  backgroundColor: rgb(0, 1, 0),
  borderColor: rgb(0, 0, 1),
  borderWidth: 2,
  rotate: degrees(90),
  font: ubuntuFont,
})

This will create a new widget for this button field.

Parameters:

Returns: void

defaultUpdateAppearances

▸ defaultUpdateAppearances(font: PDFFont): void

Overrides void

Defined in api/form/PDFButton.ts:220

Update the appearance streams for each of this button's widgets using the default appearance provider for buttons. For example:

const helvetica = await pdfDoc.embedFont(StandardFonts.Helvetica)
const button = form.getButton('some.button.field')
button.defaultUpdateAppearances(helvetica)

Parameters:

Returns: void

disableExporting

▸ disableExporting(): void

Inherited from PDFField.disableExporting

Defined in api/form/PDFField.ts:247

Indicate that this field's value should not be exported when the form is submitted in a PDF reader. For example:

const field = form.getField('some.field')
field.disableExporting()

Returns: void

disableReadOnly

▸ disableReadOnly(): void

Inherited from PDFField.disableReadOnly

Defined in api/form/PDFField.ts:170

Allow users to interact with this field and change its value in PDF readers via mouse and keyboard input. For example:

const field = form.getField('some.field')
field.disableReadOnly()

Returns: void

disableRequired

▸ disableRequired(): void

Inherited from PDFField.disableRequired

Defined in api/form/PDFField.ts:208

Do not require this field to have a value when the form is submitted. For example:

const field = form.getField('some.field')
field.disableRequired()

Returns: void

enableExporting

▸ enableExporting(): void

Inherited from PDFField.enableExporting

Defined in api/form/PDFField.ts:235

Indicate that this field's value should be exported when the form is submitted in a PDF reader. For example:

const field = form.getField('some.field')
field.enableExporting()

Returns: void

enableReadOnly

▸ enableReadOnly(): void

Inherited from PDFField.enableReadOnly

Defined in api/form/PDFField.ts:158

Prevent PDF readers from allowing users to interact with this field or change its value. The field will not respond to mouse or keyboard input. For example:

const field = form.getField('some.field')
field.enableReadOnly()

Useful for fields whose values are computed, imported from a database, or prefilled by software before being displayed to the user.

Returns: void

enableRequired

▸ enableRequired(): void

Inherited from PDFField.enableRequired

Defined in api/form/PDFField.ts:196

Require this field to have a value when the form is submitted. For example:

const field = form.getField('some.field')
field.enableRequired()

Returns: void

getName

▸ getName(): string

Inherited from PDFField.getName

Defined in api/form/PDFField.ts:128

Get the fully qualified name of this field. For example:

const fields = form.getFields()
fields.forEach(field => {
  const name = field.getName()
  console.log('Field name:', name)
})

Note that PDF fields are structured as a tree. Each field is the descendent of a series of ancestor nodes all the way up to the form node, which is always the root of the tree. Each node in the tree (except for the form node) has a partial name. Partial names can be composed of any unicode characters except a period (.). The fully qualified name of a field is composed of the partial names of all its ancestors joined with periods. This means that splitting the fully qualified name on periods and taking the last element of the resulting array will give you the partial name of a specific field.

Returns: string

The fully qualified name of this field.

isExported

▸ isExported(): boolean

Inherited from PDFField.isExported

Defined in api/form/PDFField.ts:223

Returns true if this field's value should be exported when the form is submitted. See PDFField.enableExporting and PDFField.disableExporting. For example:

const field = form.getField('some.field')
if (field.isExported()) console.log('Exporting is enabled')

Returns: boolean

Whether or not this field's value should be exported.

isReadOnly

▸ isReadOnly(): boolean

Inherited from PDFField.isReadOnly

Defined in api/form/PDFField.ts:143

Returns true if this field is read only. This means that PDF readers will not allow users to interact with the field or change its value. See PDFField.enableReadOnly and PDFField.disableReadOnly. For example:

const field = form.getField('some.field')
if (field.isReadOnly()) console.log('Read only is enabled')

Returns: boolean

Whether or not this is a read only field.

isRequired

▸ isRequired(): boolean

Inherited from PDFField.isRequired

Defined in api/form/PDFField.ts:184

Returns true if this field must have a value when the form is submitted. See PDFField.enableRequired and PDFField.disableRequired. For example:

const field = form.getField('some.field')
if (field.isRequired()) console.log('Field is required')

Returns: boolean

Whether or not this field is required.

needsAppearancesUpdate

▸ needsAppearancesUpdate(): boolean

Overrides void

Defined in api/form/PDFButton.ts:196

Returns true if this button has been marked as dirty, or if any of this button's widgets do not have an appearance stream. For example:

const button = form.getButton('some.button.field')
if (button.needsAppearancesUpdate()) console.log('Needs update')

Returns: boolean

Whether or not this button needs an appearance update.

setFontSize

▸ setFontSize(fontSize: number): void

Defined in api/form/PDFButton.ts:116

Set the font size for this field. Larger font sizes will result in larger text being displayed when PDF readers render this button. Font sizes may be integer or floating point numbers. Supplying a negative font size will cause this method to throw an error.

For example:

const button = form.getButton('some.button.field')
button.setFontSize(4)
button.setFontSize(15.7)

This method depends upon the existence of a default appearance (/DA) string. If this field does not have a default appearance string, or that string does not contain a font size (via the Tf operator), then this method will throw an error.

Parameters:

Returns: void

setImage

▸ setImage(image: PDFImage, alignment: ImageAlignment): void

Defined in api/form/PDFButton.ts:81

Display an image inside the bounds of this button's widgets. For example:

const pngImage = await pdfDoc.embedPng(...)
const button = form.getButton('some.button.field')
button.setImage(pngImage, ImageAlignment.Center)

This will update the appearances streams for each of this button's widgets.

Parameters:

Returns: void

updateAppearances

▸ updateAppearances(font: PDFFont, provider?: AppearanceProviderFor‹PDFButton›): void

Defined in api/form/PDFButton.ts:244

Update the appearance streams for each of this button's widgets using the given appearance provider. If no provider is passed, the default appearance provider for buttons will be used. For example:

const helvetica = await pdfDoc.embedFont(StandardFonts.Helvetica)
const button = form.getButton('some.button.field')
button.updateAppearances(helvetica, (field, widget, font) => {
  ...
  return {
    normal: drawButton(...),
    down: drawButton(...),
  }
})

Parameters:

Returns: void

Static of

▸ of(acroPushButton: PDFAcroPushButton, ref: PDFRef, doc: PDFDocument): PDFButton‹›

Defined in api/form/PDFButton.ts:47

NOTE: You probably don't want to call this method directly. Instead, consider using the PDFForm.getButton method, which will create an instance of PDFButton for you.

Create an instance of PDFButton from an existing acroPushButton and ref

Parameters:

Returns: PDFButton‹›