formatters.ts

import * as moment from 'moment';

export type IFormatter = (val: any, data: object) => any;

/**
 * Formatter methods which can be used with {@link Field.getFormatter} and
 * {@link Field.setFormatter}.
 *
 * The methods in this class return a function for use with the formatter
 * methods. Each method may define its own parameters that configure how
 * the formatter operates. For example the date / time formatters take
 * information on the formatting to be used.
 *
 * @export
 */
export default class Formatter {
	/**
	 * Convert from SQL date / date time format (ISO8601) to a format given
	 * by the options parameter. Typically used with a get formatter.
	 *
	 * Uses MomentJS - formats are defined by Moment.
	 *
	 * @static
	 * @param {string} format Format to convert to.
	 * @returns {IFormatter} Configured formatter function
	 */
	public static sqlDateToFormat( format: string ): IFormatter {
		return function(val: any, data: object ) {
			if ( val === null ) {
				return null;
			}

			return moment( val, 'YYYY-MM-DD' ).format( format );
		};
	}

	/**
	 * Convert to SQL date / date time format (ISO8601) from a format given
	 * by the options parameter. Typically used with a set formatter.
	 *
	 * Uses MomentJS - formats are defined by Moment.
	 *
	 * @static
	 * @param {string} format Format to convert from.
	 * @returns {IFormatter} Configured formatter function
	 */
	public static formatToSqlDate( format: string ): IFormatter {
		return function(val: any, data: object ) {
			if ( val === null ) {
				return null;
			}

			return moment( val, format ).format( 'YYYY-MM-DD' );
		};
	}

	/**
	 * Convert from one date time format to another.
	 *
	 * Uses MomentJS - formats are defined by Moment.
	 *
	 * @static
	 * @param {string} from From format
	 * @param {string} to To format.
	 * @returns {IFormatter} Configured formatter function
	 */
	public static dateTime( from: string, to: string ): IFormatter {
		return function(val: any, data: object ) {
			if ( val === null ) {
				return null;
			}

			return moment( val, from ).format( to );
		};
	}

	/**
	 * Convert a string of values into an array for use with checkboxes.
	 *
	 * @static
	 * @param {string} [delimiter='|'] Delimiter string (i.e. what to split on)
	 * @returns {IFormatter} Configured formatter function
	 */
	public static explode( delimiter: string = '|' ): IFormatter {
		return function(val: any, data: object ) {
			return val.toString().split( delimiter );
		};
	}

	/**
	 * Convert an array of values from a checkbox into a string which can be
	 * used to store in a text field in a database.
	 *
	 * @static
	 * @param {string} [delimiter='|'] Delimiter string (i.e. what to join on)
	 * @returns {IFormatter} Configured formatter function
	 */
	public static implode( delimiter: string = '|' ): IFormatter {
		return function(val: any, data: object ) {
			return val.join( delimiter );
		};
	}

	/**
	 * Convert an empty string to `null`. Null values are very useful in
	 * databases, but HTTP variables have no way of representing `null` as a
	 * value, often leading to an empty string and null overlapping. This method
	 * will check the value to operate on and return null if it is empty.
	 *
	 * @static
	 * @param {*} emptyValue Value to use if an empty value is submitted. `null`
	 *   is the typical value.
	 * @returns {IFormatter} Configured formatter function
	 */
	public static ifEmpty( emptyValue: any ): IFormatter {
		return function(val: any, data: object ) {
			return val === '' ?
				emptyValue :
				val;
		};
	}

	/**
	 * Convert a number from using any character other than a period (dot) to
	 * one which does use a period. This is useful for allowing numeric user
	 * input in regions where a comma is used as the decimal character. Use with
	 * a set formatter.
	 *
	 * @static
	 * @param {string} [char=','] Decimal place character
	 * @returns {IFormatter} Configured formatter function
	 */
	public static fromDecimalChar( char: string = ',' ): IFormatter {
		return function(val: any, data: object ) {
			return val.replace( char, '.' );
		};
	}

	/**
	 * Convert a number with a period (dot) as the decimal character to use
	 * a different character (typically a comma). Use with a get formatter.
	 *
	 * @static
	 * @param {string} [char=','] Decimal place character
	 * @returns {IFormatter} Configured formatter function
	 */
	public static toDecimalChar( char: string = ',' ): IFormatter {
		return function(val: any, data: object ) {
			return val.replace( '.', char );
		};
	}
}