inputmask-core

A standalone input mask implementation, which is independent of any GUI.

InputMask encapsulates editing operations on a string which must conform to a fixed-width pattern defining editable positions and the types of data they may contain, plus optional static characters which may not be edited.

Install

npm install inputmask-core

Usage

Importing and creating an instance:

var InputMask = require('inputmask-core')
 
var mask = new InputMask({pattern: '11/11/1111'})

Examples of editing a mask:

/*  Invalid input is rejected */
mask.input('a')
// → false
 
/* Valid input is accepted */
mask.input('1')
// → true
mask.getValue()
// → '1_/__/____'
 
/* Editing operations update the cursor position */
mask.selection
// → {start: 1, end: 1}
 
/* Pasting is supported */
mask.paste('2345678')
// → true
mask.getValue()
// → '12/34/5678'
 
/* Backspacing is supported */
mask.backspace()
// → true
mask.getValue()
// → '12/34/567_'
 
/* Editing operations also know how to deal with selected ranges */
mask.selection = {start: 0, end: 9}
mask.backspace()
// → true
mask.getValue()
// → '__/__/____'

API

See the Types section below for type definitions referenced in this section.

InputMask(options:InputMaskOptions)

Constructs a new InputMask - use of new is optional, so these examples are equivalent:

var mask = new InputMask({pattern: '1111-1111', value: '12345678'})

var mask = InputMask({pattern: '1111-1111', value: '12345678'})

InputMask public properties, getters & setters

selection : Selection

The current selection within the input.

If start and end are the same, this indicates the current cursor position in the string, otherwise it indicates a range of selected characters within the string.

selection will be updated as necessary by editing methods, e.g. if you input() a valid character, selection will be updated to place the cursor after the newly-inserted character.

If you're using InputMask as the backend for an input mask in a GUI, make sure selection is accurate before calling any editing methods!

setSelection(selection: Selection) : boolean

Sets the selection and performs an editable cursor range check if the selection change sets the cursor position (i.e. start and end are the same).

If the mask's pattern begins or ends with static characters, this method will prevent the cursor being placed prior to a leading static character or beyond a tailing static character. Only use this method to set selection if this is the behaviour you want.

Returns true if the selection needed to be adjusted as described above, false otherwise.

getValue() : string

Gets the current value in the mask, which will always conform to the mask's pattern.

setValue(value: string)

Overwrites the current value in the mask.

The given value will be applied to the mask's pattern, with invalid - or missing - editable characters replaced with placeholders.

The value may optionally contain static parts of the mask's pattern.

setPattern(pattern: string, value: ?string)

Overwrites the mask's pattern.

A new value can also be provided - if not provided, the value will default to blank, clearing the mask.

InputMask editing methods

Editing methods will not allow the string being edited to contain invalid values according to the mask's pattern.

Any time an editing method results in either the value or the selection changing, it will return true.

Otherwise, if an invalid (e.g. trying to input a letter where the pattern specifies a number) or meaningless (e.g. backspacing when the cursor is at the start of the string) editing operation is attempted, it will return false.

input(character: string) : boolean

Applies a single character of input based on the current selection.

• If a text selection has been made, editable characters within the selection will be blanked out, the cursor will be moved to the start of the selection and input will proceed as below.

• If the cursor is positioned before an editable character and the input is valid, the input will be added. The cursor will then be advanced to the next editable character in the mask.

• If the cursor is positioned before a static part of the mask, the cursor will be advanced to the next editable character.

After input has been added, the cursor will be advanced to the next editable character position.

backspace() : boolean

Performs a backspace operation based on the current selection.

• If a text selection has been made, editable characters within the selection will be blanked out and the cursor will be placed at the start of the .selection

• If the cursor is positioned after an editable character, that character will be blanked out and the cursor will be placed before it.

• If the cursor is positioned after a static part of the mask, the cursor will be placed before it.

paste(input: string): boolean

Applies a string of input based on the current selection.

This behaves the same as - and is effectively like - calling input() for each character in the given string with one key difference - if any character within the input is determined to be invalid, the entire paste operation fails and the mask's value and selection are unaffected.

Pasted input may optionally contain static parts of the mask's pattern.

Types

These type definitions are purely for reference, they're not part of the API exported by this module.

Selection : {start: number; end: number}

An object with start and end properties, where end >= start.

InputMaskOptions

{pattern: string, value: ?string, selection: ?Selection}

Options for the InputMask constructor.

pattern

A masking pattern. The following characters signify editable parts of the mask:

• 1 - number
• A - letter
• * - alphanumeric

All other characters are treated as static.

A pattern must be provided and must contain at least one editable character, or an Error will be thrown.

Example patterns

• Credit card number: 1111 1111 1111 1111
• Date: 11/11/1111
• ISO date: 1111-11-11
• Time: 11:11
• Canadian postal code: A1A 1A1
• Norn Iron license plate: AAA 1111

value

An optional initial value for the mask - see setValue() above for more details.

selection

An optional default selection - see selection above for more details.

MIT Licensed