happypdf / PDFCheckBox

Class: PDFCheckBox

Defined in: src/api/form/PDFCheckBox.ts:33

Represents a check box field of a [[PDFForm]].

[[PDFCheckBox]] fields are interactive boxes that users can click with their mouse. This type of [[PDFField]] has two states: on and off. The purpose of a check box is to enable users to select from one or more options, where each option is represented by a single check box. Check boxes are typically square in shape and display a check mark when they are in the on state.

Extends

• PDFField

Properties

acroField

readonly acroField: PDFAcroCheckBox;

Defined in: src/api/form/PDFCheckBox.ts:49

The low-level PDFAcroCheckBox wrapped by this check box.

Overrides

PDFField.acroField

---

doc

readonly doc: PDFDocument;

Defined in: src/api/form/PDFField.ts:96

The document to which this field belongs.

Inherited from

PDFField.doc

---

ref

readonly ref: PDFRef;

Defined in: src/api/form/PDFField.ts:93

The unique reference assigned to this field within the document.

Inherited from

PDFField.ref

Methods

addToPage()

addToPage(page, options?): void;

Defined in: src/api/form/PDFCheckBox.ts:150

Show this check box on the specified page. For example:

const helvetica = await pdfDoc.embedFont(StandardFonts.Helvetica)
const page = pdfDoc.addPage()

const form = pdfDoc.getForm()
const checkBox = form.createCheckBox('some.checkBox.field')

checkBox.addToPage(page, {
  x: 50,
  y: 75,
  width: 25,
  height: 25,
  textColor: rgb(1, 0, 0),
  backgroundColor: rgb(0, 1, 0),
  borderColor: rgb(0, 0, 1),
  borderWidth: 2,
  rotate: degrees(90),
})

This will create a new widget for this check box field.

Parameters

Parameter	Type	Description
page	PDFPage	The page to which this check box widget should be added.
options?	FieldAppearanceOptions	The options to be used when adding this check box widget.

Returns

void

---

check()

check(): void;

Defined in: src/api/form/PDFCheckBox.ts:84

Mark this check box. This operation is analogous to a human user clicking a check box to fill it in a PDF reader. This method will update the underlying state of the check box field to indicate it has been selected. PDF libraries and readers will be able to extract this value from the saved document and determine that it was selected.

For example:

const checkBox = form.getCheckBox('some.checkBox.field')
checkBox.check()

This method will mark this check box as dirty, causing its appearance streams to be updated when either [[PDFDocument.save]] or [[PDFForm.updateFieldAppearances]] is called. The updated appearance streams will display a check mark inside the widgets of this check box field.

Returns

void

---

createImageAppearanceStream()

protected createImageAppearanceStream(
   widget, 
   image, 
   alignment): PDFRef;

Defined in: src/api/form/PDFField.ts:498

Create a FormXObject of the supplied image and add it to context. The FormXObject size is calculated based on the widget (including the alignment).

Parameters

Parameter	Type	Description
widget	PDFWidgetAnnotation	The widget that should display the image.
image	PDFImage	The image that should be displayed.
alignment	ImageAlignment	The alignment of the image.

Returns

PDFRef

The ref for the FormXObject that was added to the context.

Inherited from

PDFField.createImageAppearanceStream

---

createWidget()

protected createWidget(options): PDFWidgetAnnotation;

Defined in: src/api/form/PDFField.ts:333

Parameters

Parameter	Type
options	{ backgroundColor?: Color; borderColor?: Color; borderWidth: number; caption?: string; height: number; hidden?: boolean; page?: PDFRef; rotate: Rotation; textColor?: Color; width: number; x: number; y: number; }
options.backgroundColor?	Color
options.borderColor?	Color
options.borderWidth	number
options.caption?	string
options.height	number
options.hidden?	boolean
options.page?	PDFRef
options.rotate	Rotation
options.textColor?	Color
options.width	number
options.x	number
options.y	number

Returns

PDFWidgetAnnotation

Inherited from

PDFField.createWidget

---

defaultUpdateAppearances()

defaultUpdateAppearances(): void;

Defined in: src/api/form/PDFCheckBox.ts:219

Update the appearance streams for each of this check box's widgets using the default appearance provider for check boxes. For example:

const checkBox = form.getCheckBox('some.checkBox.field')
checkBox.defaultUpdateAppearances()

Returns

void

Overrides

PDFField.defaultUpdateAppearances

---

disableExporting()

disableExporting(): void;

Defined in: src/api/form/PDFField.ts:251

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

Inherited from

PDFField.disableExporting

---

disableReadOnly()

disableReadOnly(): void;

Defined in: src/api/form/PDFField.ts:174

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

Inherited from

PDFField.disableReadOnly

---

disableRequired()

disableRequired(): void;

Defined in: src/api/form/PDFField.ts:212

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

Inherited from

PDFField.disableRequired

---

enableExporting()

enableExporting(): void;

Defined in: src/api/form/PDFField.ts:239

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

Inherited from

PDFField.enableExporting

---

enableReadOnly()

enableReadOnly(): void;

Defined in: src/api/form/PDFField.ts:162

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

Inherited from

PDFField.enableReadOnly

---

enableRequired()

enableRequired(): void;

Defined in: src/api/form/PDFField.ts:200

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

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

Returns

void

Inherited from

PDFField.enableRequired

---

getAction()

getAction(): PDFJavaScriptAction | undefined;

Defined in: src/api/form/PDFField.ts:290

Get the default action (A) for this field. This is typically a submit or reset action, or can be a JavaScript action. For example:

const field = form.getField('some.field')
const action = field.getAction()
if (action) {
  console.log('Action script:', action.getScript())
}

Returns

PDFJavaScriptAction | undefined

The JavaScript action, or undefined if not a JavaScript action.

Inherited from

PDFField.getAction

---

getJavaScriptActions()

getJavaScriptActions(): 
  | JavaScriptActionMap
  | undefined;

Defined in: src/api/form/PDFField.ts:271

Get the JavaScript actions associated with this field. Returns a map of action types to JavaScript actions. For example:

const field = form.getField('some.field')
const actions = field.getJavaScriptActions()
if (actions.keystroke) {
  console.log('Keystroke script:', actions.keystroke.getScript())
}
if (actions.calculate) {
  console.log('Calculate script:', actions.calculate.getScript())
}

Returns

| JavaScriptActionMap | undefined

A map of JavaScript actions for this field, or undefined if none exist.

Inherited from

PDFField.getJavaScriptActions

---

getName()

getName(): string;

Defined in: src/api/form/PDFField.ts:132

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.

Inherited from

PDFField.getName

---

isChecked()

isChecked(): boolean;

Defined in: src/api/form/PDFCheckBox.ts:120

Returns true if this check box is selected (either by a human user via a PDF reader, or else programmatically via software). For example:

const checkBox = form.getCheckBox('some.checkBox.field')
if (checkBox.isChecked()) console.log('check box is selected')

Returns

boolean

Whether or not this check box is selected.

---

isDirty()

protected isDirty(): boolean;

Defined in: src/api/form/PDFField.ts:329

Returns

boolean

Inherited from

PDFField.isDirty

---

isExported()

isExported(): boolean;

Defined in: src/api/form/PDFField.ts:227

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.

Inherited from

PDFField.isExported

---

isReadOnly()

isReadOnly(): boolean;

Defined in: src/api/form/PDFField.ts:147

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.

Inherited from

PDFField.isReadOnly

---

isRequired()

isRequired(): boolean;

Defined in: src/api/form/PDFField.ts:188

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.

Inherited from

PDFField.isRequired

---

markAsClean()

protected markAsClean(): void;

Defined in: src/api/form/PDFField.ts:325

Returns

void

Inherited from

PDFField.markAsClean

---

markAsDirty()

protected markAsDirty(): void;

Defined in: src/api/form/PDFField.ts:321

Returns

void

Inherited from

PDFField.markAsDirty

---

needsAppearancesUpdate()

needsAppearancesUpdate(): boolean;

Defined in: src/api/form/PDFCheckBox.ts:197

Returns true if any of this check box's widgets do not have an appearance stream for its current state. For example:

const checkBox = form.getCheckBox('some.checkBox.field')
if (checkBox.needsAppearancesUpdate()) console.log('Needs update')

Returns

boolean

Whether or not this check box needs an appearance update.

Overrides

PDFField.needsAppearancesUpdate

---

of()

static of(
   acroCheckBox, 
   ref, 
   doc): PDFCheckBox;

Defined in: src/api/form/PDFCheckBox.ts:45

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

Create an instance of [[PDFCheckBox]] from an existing acroCheckBox and ref

Parameters

Parameter	Type	Description
acroCheckBox	PDFAcroCheckBox	The underlying PDFAcroCheckBox for this check box.
ref	PDFRef	The unique reference for this check box.
doc	PDFDocument	The document to which this check box will belong.

Returns

PDFCheckBox

---

uncheck()

uncheck(): void;

Defined in: src/api/form/PDFCheckBox.ts:106

Clears this check box. This operation is analogous to a human user clicking a check box to unmark it in a PDF reader. This method will update the underlying state of the check box field to indicate it has been deselected. PDF libraries and readers will be able to extract this value from the saved document and determine that it was not selected.

For example:

const checkBox = form.getCheckBox('some.checkBox.field')
checkBox.uncheck()

This method will mark this check box as dirty. See [[PDFCheckBox.check]] for more details about what this means.

Returns

void

---

updateAppearances()

updateAppearances(provider?): void;

Defined in: src/api/form/PDFCheckBox.ts:240

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

const checkBox = form.getCheckBox('some.checkBox.field')
checkBox.updateAppearances((field, widget) => {
  ...
  return {
    normal: { on: drawCheckBox(...), off: drawCheckBox(...) },
    down: { on: drawCheckBox(...), off: drawCheckBox(...) },
  }
})

Parameters

Parameter	Type	Description
provider?	CheckBoxAppearanceProvider	Optionally, the appearance provider to be used for generating the contents of the appearance streams.

Returns

void

---

updateOnOffWidgetAppearance()

protected updateOnOffWidgetAppearance(
   widget, 
   onValue, 
   __namedParameters): void;

Defined in: src/api/form/PDFField.ts:412

Parameters

Parameter	Type
widget	PDFWidgetAnnotation
onValue	PDFName
__namedParameters	AppearanceMapping<{ off: PDFOperator[]; on: PDFOperator[]; }>

Returns

void

Inherited from

PDFField.updateOnOffWidgetAppearance

---

updateWidgetAppearances()

protected updateWidgetAppearances(widget, __namedParameters): void;

Defined in: src/api/form/PDFField.ts:429

Parameters

Parameter	Type
widget	PDFWidgetAnnotation
__namedParameters	AppearanceMapping<PDFRef | PDFDict>

Returns

void

Inherited from

PDFField.updateWidgetAppearances

---

updateWidgetAppearanceWithFont()

protected updateWidgetAppearanceWithFont(
   widget, 
   font, 
   __namedParameters): void;

Defined in: src/api/form/PDFField.ts:400

Parameters

Parameter	Type
widget	PDFWidgetAnnotation
font	PDFFont
__namedParameters	AppearanceMapping<PDFOperator[]>

Returns

void

Inherited from

PDFField.updateWidgetAppearanceWithFont