WordPressで郵便番号検索プラグインを作ってみよう

<?php
// config.php

return array(
    'API_URL' => 'https://zipcloud.ibsnet.co.jp/api/search',
    'ZIPCODE_PARAM' => 'zipcode'
);

// zipcode-search-plugin.php

$config = include(plugin_dir_path(__FILE__) . 'config.php');

function zipcode_search_form() {
    $form = '<form action="" method="post" id="zipcode-search-form">
                <label for="zipcode">郵便番号:</label>
                <input type="text" name="zipcode" id="zipcode" required>
                <input type="submit" value="検索">
             </form>
             <div id="address-result"></div>';
    return $form;
}

jQuery(document).ready(function($) {
    $('#zipcode-search-form').submit(function(e) {
        e.preventDefault();
        var zipcode = $('#zipcode').val();
        $.post(zipcodeSearch.ajax_url, {
            action: 'zipcode_search',
            zipcode: zipcode
        }, function(data) {
            $('#address-result').html(data);
        });
    });
});

<?php
/**
 * Plugin Name: Zipcode Search Plugin
 * Description: A plugin to search addresses from Zipcode using ZipCloud API.
 * Version: 1.0
 * Author: Hidemasa Nakada
 */

// config.php から設定を読み込む
$config = include(plugin_dir_path(__FILE__) . 'config.php');

function zipcode_search_form() {
    $form = '<form action="" method="post" id="zipcode-search-form">
                <label for="zipcode">郵便番号:</label>
                <input type="text" name="zipcode" id="zipcode" required>
                <input type="submit" value="検索">
             </form>
             <div id="address-result"></div>';
    return $form;
}
add_shortcode('zipcode_search', 'zipcode_search_form');

function zipcode_search_scripts() {
    wp_enqueue_script('zipcode-search-ajax', plugin_dir_url(__FILE__) . 'js/zipcode-search.js', array('jquery'), null, true);
    wp_localize_script('zipcode-search-ajax', 'zipcodeSearch', array('ajax_url' => admin_url('admin-ajax.php')));
}
add_action('wp_enqueue_scripts', 'zipcode_search_scripts');

function zipcode_search_ajax_handler() {
    global $config;
    $zipcode = isset($_POST['zipcode']) ? sanitize_text_field($_POST['zipcode']) : '';

    $api_url = $config['API_URL'];
    $param_name = $config['ZIPCODE_PARAM'];

    $response = wp_remote_get("$api_url?$param_name=$zipcode");
    if (is_wp_error($response)) {
        echo 'APIリクエスト中にエラーが発生しました。';
        wp_die();
    }

    $body = wp_remote_retrieve_body($response);
    $data = json_decode($body, true);

    if (isset($data['results'][0])) {
        $result = $data['results'][0];
        echo $result['address1'] . $result['address2'] . $result['address3'];
    } else {
        echo '住所が見つかりませんでした。';
    }

    wp_die();
}
add_action('wp_ajax_zipcode_search', 'zipcode_search_ajax_handler');
add_action('wp_ajax_nopriv_zipcode_search', 'zipcode_search_ajax_handler');

jQuery(document).ready(function($) {
    $('#zipcode-search-form').submit(function(e) {
        e.preventDefault();
        var zipcode = $('#zipcode').val();
        $.post(zipcodeSearch.ajax_url, {
            action: 'zipcode_search',
            zipcode: zipcode
        }, function(data) {
            $('#address-result').html(data);
        });
    });
});