Tutorial: Localizers (formatters and deformatters)

The file ./src/lib/localization.js provides "localization agents" that know how to:

• Localize a data value into a string representation for:
  • Grid display
  • Cell editor pre-load
• Standardize a localized string back into a typed primitive (or object) for writing back to a data row.
• Check an edited localized string for syntax or just for illegal characters (implementation optional).

The API includes factory functions that invoke the Intl API for numbers and dates. On instantiation, the singleton Localization object "constructs" basic number and date localizers using these factory functions. It also defines several other localizers (). You can also add your own custom localizers using the grid.localization.add method. For numbers and dates, use the factory functions. For other formats, supply an object that conforms to the localization API interface (has the required format and parse methods; and the optional isValid method).

For illustration purposes, however, here's a simple implementation of this localizer:

var hhmm = {
    // returns formatted string from number
    format: function(mins) {
        var hh = Math.floor(mins / 60),
            mm = (mins % 60 + 100 + '').substr(1, 2);
        return hh + ':' + mm;
    },

    // tests input for full validity
    invalid: function(hhmm) {
        return /^([01]?\d|2[0-3]):[0-5]\d$/.test(hhmm); // 23:59 max
    },

    // returns number from formatted string
    parse: function(hhmm) {
        var parts = hhmm.match(/^(\d+):(\d{2})$/);
        return Number(parts[1]) * 60 + Number(parts[2]);
    }
};