# Class: PageLabel

## PDFNet. PageLabel

#### new PageLabel()

  PDF page labels can be used to describe a page. This is used to allow for non-sequential page numbering or the addition of arbitrary labels for a page (such as the inclusion of Roman numerals at the beginning of a book). PDFNet PageLabel object can be used to specify the numbering style to use (for example, upper- or lower-case Roman, decimal, and so forth), the starting number for the first page, and an arbitrary prefix to be pre-appended to each number (for example, "A-" to generate "A-1", "A-2", "A-3", and so forth.)

  PageLabel corresponds to the PDF Page Label object (Section 8.3.1, 'Page Labels' in the PDF Reference Manual.

  Each page in a PDF document is identified by an integer page index that expresses the page's relative position within the document. In addition, a document may optionally define page labels to identify each page visually on the screen or in print. Page labels and page indices need not coincide: the indices are fixed, running consecutively through the document starting from 1 for the first page, but the labels can be specified in any way that is appropriate for the particular document. For example, if the document begins with 12 pages of front matter numbered in roman numerals and the remainder of the document is numbered in Arabic, the first page would have a page index of 1 and a page label of i, the twelfth page would have index 12 and label xii, and the thirteenth page would have index 13 and label 1.

  For purposes of page labeling, a document can be divided into labeling ranges, each of which is a series of consecutive pages using the same numbering system. Pages within a range are numbered sequentially in ascending order. A page's label consists of a numeric portion based on its position within its labeling range, optionally preceded by a label prefix denoting the range itself. For example, the pages in an appendix might be labeled with decimal numeric portions prefixed with the string "A-" and the resulting page labels would be "A-1", "A-2",

### Methods

#### <static> create(doc, style, prefix, start_at)

  Creates a new PageLabel.

  ##### Parameters:

  Name | Type | Description
  --- | --- | ---
  `doc` | PDFNet.SDFDoc | A document to which the page label is added.
  `style` | number/enum |
      PDFNet.PageLabel.Style = {
      	e_decimal : 0
      	e_roman_uppercase : 1
      	e_roman_lowercase : 2
      	e_alphabetic_uppercase : 3
      	e_alphabetic_lowercase : 4
      	e_none : 5
      }
  The numbering style for the label.
  `prefix` | string | The string used to prefix the numeric portion of the page label.
  `start_at` | number | the value to use when generating the numeric portion of the first label in this range; must be greater than or equal to 1.

  ##### Returns:

  A promise that resolves to newly created PageLabel object.

  Type
    PDFNet.pagelabel

#### <static> createFromObj(l, first_page, last_page)

  ##### Parameters:

  Name | Type | Description
  --- | --- | ---
  `l` | PDFNet.Obj |
  `first_page` | number |
  `last_page` | number |

  ##### Returns:

  A promise that resolves to an object of type: "pagelabel"

  Type
    PDFNet.PageLabel

#### assign(right)

  ##### Parameters:

  Name | Type | Description
  --- | --- | ---
  `right` | PDFNet.pagelabel |

#### compare(d)

  ##### Parameters:

  Name | Type | Description
  --- | --- | ---
  `d` | PDFNet.pagelabel |

  ##### Returns:

  A promise that resolves to an unknown type

#### getFirstPageNum()

  ##### Returns:

  A promise that resolves to the first page in the range associated with this label or -1 if the label is not associated with any page.

  Type
    number

#### getLabelTitle(page_num)

  ##### Parameters:

  Name | Type | Description
  --- | --- | ---
  `page_num` | number |

  ##### Returns:

  A promise that resolves to an object of type: "string"

  Type
    string

#### getLastPageNum()

  ##### Returns:

  A promise that resolves to the last page in the range associated with this label or -1 if the label is not associated with any page.

  Type
    number

#### getPrefix()

  ##### Returns:

  A promise that resolves to the string used to prefix the numeric portion of the page label

  Type
    string

#### getSDFObj()

  ##### Returns:

  A promise that resolves to the pointer to the underlying SDF/Cos object.

  Type
    PDFNet.Obj

#### getStart()

  ##### Returns:

  A promise that resolves to the value to use when generating the numeric portion of the first label in this range; must be greater than or equal to 1.

  Type
    number

#### getStyle()

  ##### Returns:

  A promise that resolves to page numbering style.

  Type
    number

  ##### Example

      Return value enum:
      <pre>
      PDFNet.PageLabel.Style = {
      	e_decimal : 0
      	e_roman_uppercase : 1
      	e_roman_lowercase : 2
      	e_alphabetic_uppercase : 3
      	e_alphabetic_lowercase : 4
      	e_none : 5
      }
      </pre>

#### isValid()

  ##### Returns:

  A promise that resolves to whether this is a valid (non-null) PageLabel. If the function returns false the underlying SDF/Cos object is null or is not valid and the PageLabel object should be treated as null as well.

  Type
    boolean

#### setPrefix(prefix)

  ##### Parameters:

  Name | Type | Description
  --- | --- | ---
  `prefix` | string | the string used to prefix the numeric portion of the page label.

#### setStart(start_at)

  ##### Parameters:

  Name | Type | Description
  --- | --- | ---
  `start_at` | number | the value to use when generating the numeric portion of the first label in this range; must be greater than or equal to 1.

#### setStyle(style)

  Sets the numbering style for the label.

  ##### Parameters:

  Name | Type | Description
  --- | --- | ---
  `style` | number/enum |
      PDFNet.PageLabel.Style = {
      	e_decimal : 0
      	e_roman_uppercase : 1
      	e_roman_lowercase : 2
      	e_alphabetic_uppercase : 3
      	e_alphabetic_lowercase : 4
      	e_none : 5
      }
  the numbering style for the label. You may use label style to customize the page numbering schemes used throughout a document. There are three numbering formats: decimal (often used for normal page ranges) roman (often used for front matter such as a preface) alphabetic (often used for back matter such as appendices)

#### Search results