<vcf-month-picker>

<vcf-month-picker> is a web component for selecting a year and month, based on LitElement. It provides an easy-to-use interface for choosing months within a specified range, supporting localization, validation, and customization.

This web component follows the open-wc recommendation.

This component is part of Vaadin Component Factory.

Features

• Month & Year Selection: Allows users to pick a month and year via textfield or overlay.
• Configurable Range: Set minimum and maximum selectable years.
• Customizable Labels & Placeholders: Supports custom text for better user experience.
• Customizable formats: Different combinations of month and year placeholder possible, e.g. "MM.YYYY", "MMYY", "YY-MM", ...
• Disabled & Read-only Modes: Component can be set as non-interactive when needed.
• Clear Button Support: Option to reset the selection.
• Theming & Styling: Uses CSS custom properties for easy styling.
• Localization: Supports custom month names, months labels and formats.
• Validation & Error Handling: Marks invalid states with an error message.
• ARIA & Accessibility: Proper attributes for screen reader support.

Custom Month Names and Labels

By default, month names and labels are in English language but it can be customized through the i18n property. Please note that the object expects month names, labels and formats to be specified on customization.

Example:

<vcf-month-picker 
  label="Month Picker"  
  .i18n=${{
	monthNames: ['Enero', 'Febrero', 'Marzo', 'Abril', 'Mayo', 'Junio',
		'Julio', 'Agosto', 'Septiembre', 'Octubre', 'Noviembre', 'Diciembre'],
	monthLabels: ['Ene', 'Feb', 'Mar', 'Abr', 'May', 'Jun', 'Jul', 'Ago', 'Sep', 'Oct', 'Nov', 'Dic'],
	formats: ["MM/YYYY"]  
  }} >
</vcf-month-picker>

Custom Year-Month Formats

The component allows users to define custom formats for displaying and parsing year-month values.

Defining Custom Formats

You can specify an array of formats through the i18n property. The first format in the array is used for display, while all listed formats are used for parsing user input.

Example:

monthPicker.i18n = {
  monthNames: monthPicker.i18n.monthNames,
  monthLabels: monthPicker.i18n.monthLabels,
  formats: ['MM.YYYY', 'MM/YYYY', 'MMYYYY', 'MM-YYYY', 'YYYY.MM', 'MYYYY', 'YYYY/MM', 'MM YYYY']
};

The displayed value will use "MM.YYYY".

Users can enter values using "MM.YYYY", "MM/YYYY", "MM-YYYY" or "MMYYYY".

You may also use 1-digit month and/or 2-digit year placeholders. Be aware, that the resulting formats should be parsable and that they should not result in ambigious variants (e.g. "YYMM" and "MMYY").

Format Rules

• The year must always be two or four digits (YY or YYYY).
• The month must be one or two digits (M or MM).
• Only common date separators are supported:
  • Dot (.)
  • Slash (/)
  • Hyphen (-)
  • Space ( )
• Not separator is also supported (e.g. "MMYYYY" or "YYYYMM")
• Month position matters:
  • MM/YYYY and YYYY/MM are treated differently.
  • The component determines whether the month appears before or after the year based on the format.

2-digit year handling / reference century

When using 2-digit years, we could run into the problem, that 2-digit years can be interpreted in multiple ways. To not resulting in years, that points to the time of the Caesars, the component will automatically convert 2-digit years to 4-digit ones internally.

To accomplish this, the picker stores the last picked century internally (reference century) and applies them on any 2-digit year entered by the user via the text field. By default, the refence century refers to the current one. When a 4-digit year is entered, the reference century is updated respectivly.

Please note, that this is not the common term of century, where the current century is the 21st, but means basically the first 2 digits of a 4-digit year, i.e. entering "2025" results in the reference century "20".

Installation

npm i @vaadin-component-factory/vcf-month-picker

Usage

Once installed, import it in your application:

import '@vaadin-component-factory/vcf-month-picker';

Example

<vcf-month-picker label="Month Picker" placeholder="Select a month" clear-button-visible></vcf-month-picker>

Linting and formatting

To scan the project for linting and formatting errors, run

npm run lint

To automatically fix linting and formatting errors, run

npm run format

Running demo

1. Fork the vcf-month-picker repository and clone it locally.

2. Make sure you have npm installed.

3. When in the vcf-month-picker directory, run npm install to install dependencies.

4. Run npm start to open the demo.

Publishing

Update the version in the package.json, vcf-month-picker-calendar.ts and vcf-month-picker.ts. Run npm login use a login that can publish to the organization vaadin-component-factory Run npm run prepublish Run npm publish

If you want to publish a beta version, use npm publish --tag=beta

Contributing

To contribute to the component, please read the guideline first.

License

Distributed under Apache Licence 2.0.

Sponsored development

Major pieces of development of this add-on has been sponsored by multiple customers of Vaadin. Read more about Expert on Demand at: Support and Pricing.