ES6 YubinBango

YubinBango.js

/**
 * 郵便番号自動入力クラス
 * YubinBango
 *
 * [SOURCE]
 * https://github.com/kobabasu/micro-flux
 *
 * [LATEST VERSION]
 * https://gist.github.com/hnq90/1c63e82377b5cac9ec0ed7a1d93269d2
 *
 * [HOW TO USE]
 * new YubinBango().fetch(zipCode, address => {
 *   if (address === false) {
 *     alert('Invalid Zipcode')
 *   } else {
 *     // var { region_id, region, locality, street, extended } = address
 *     console.log(address)
 *   }
 * })
 *
 * Modified by: Mike Alvarez
 *
 * changelog
 * - added functionality to be able to acknowledge custom element for attachment
 * - fixed compatibility issue regarding IE browser
 */

var CACHE = [];

var DATA_URL = 'https://yubinbango.github.io/yubinbango-data/data';
var ZIPCODE_LENGTH = 7;
var JSONP_CALLBACK = '$yubin';
var REGION = [
    null, '北海道', '青森県', '岩手県', '宮城県',
    '秋田県', '山形県', '福島県', '茨城県', '栃木県',
    '群馬県', '埼玉県', '千葉県', '東京都', '神奈川県',
    '新潟県', '富山県', '石川県', '福井県', '山梨県',
    '長野県', '岐阜県', '静岡県', '愛知県', '三重県',
    '滋賀県', '京都府', '大阪府', '兵庫県', '奈良県',
    '和歌山県', '鳥取県', '島根県', '岡山県', '広島県',
    '山口県', '徳島県', '香川県', '愛媛県', '高知県',
    '福岡県', '佐賀県', '長崎県', '熊本県', '大分県',
    '宮崎県', '鹿児島県', '沖縄県'
];

/**
 * polyfill for method `assign` causing an error on IE 'Object doesn't support property or method 'assign''
 *
 * references:
 *  - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/assign
 *  - https://stackoverflow.com/questions/35215360/getting-error-object-doesnt-support-property-or-method-assign
 *
 */
if (typeof Object.assign != 'function') {
  Object.assign = function(target, varArgs) { // .length of function is 2
    'use strict';
    if (target == null) { // TypeError if undefined or null
      throw new TypeError('Cannot convert undefined or null to object');
    }

    var to = Object(target);

    for (var index = 1; index < arguments.length; index++) {
      var nextSource = arguments[index];

      if (nextSource != null) { // Skip over if undefined or null
        for (var nextKey in nextSource) {
          // Avoid bugs when hasOwnProperty is shadowed
          if (Object.prototype.hasOwnProperty.call(nextSource, nextKey)) {
            to[nextKey] = nextSource[nextKey];
          }
        }
      }
    }
    return to;
  };
}

var YubinBango = function() {
};

YubinBango.prototype.cacheCheck = function (zip01) {
    if (CACHE[zip01]) {
      return true;
    }
    return false;
};

YubinBango.prototype.validate = function (value) {
    return value.length === ZIPCODE_LENGTH;
};

YubinBango.prototype.jsonp = function (url, callback) {
    window[JSONP_CALLBACK] = function(data) {
        return callback(data);
    }

    var script_tag = document.createElement('script');
    script_tag.setAttribute('type', 'text/javascript');
    script_tag.setAttribute('charset', 'UTF-8');
    script_tag.setAttribute('src', url);
    document.body.appendChild(script_tag);
};

YubinBango.prototype.selectAddress = function (zipCode, address) {
    var result = {
      region_id: '',
      region: '',
      locality: '',
      street: '',
      extended: ''
    };

    if (address) {

      result = Object.assign(
        {},
        result,
        {
          region_id: address[0],
          region: REGION[address[0]],
          locality: address[1],
          street: address[2],
          extended: address[3] || ''
        }
      );

      return result;
    }

    return false;
};

YubinBango.prototype.getAddress = function (zipCode, callback) {
    var ZIP01 = zipCode.substr(0, 3);

    if (YubinBango.prototype.cacheCheck(ZIP01)) {
        callback(YubinBango.prototype.selectAddress(zipCode, CACHE[ZIP01][zipCode]));
    } else {
        YubinBango.prototype.jsonp(DATA_URL + '/' + ZIP01 + '.js', function(data) {
            if (data && Object.keys(data).length > 0) {
                CACHE[ZIP01] = data;
                callback(YubinBango.prototype.selectAddress(zipCode, data[zipCode]));
            } else {
                callback(false);
            }
        });
    }
};

YubinBango.prototype.fetch = function (zipCode, callback) {
    if (zipCode && typeof zipCode === 'string') {
        var zipCode = zipCode.replace(/[０-９]/g, function(str) {
            return String.fromCharCode(str.charCodeAt(0) - 65248);
        }).match(/\d/g).join('');

        if (YubinBango.prototype.validate(zipCode)) {
            YubinBango.prototype.getAddress(zipCode, callback);
        } else {
            callback(false);
        }
    }
};

Sample Usage:

var yb = new YubinBango();
var zipcode = document.getElementById('#zipcode').value;

if (zipcode.match(/\d/g) && zipcode) {
    yb.fetch(zipcode, function(response) {
        console.log(response);
    });
}