WordPress Transients API を使うときの覚書 ref: http://qiita.com/gatespace/items/90fad367f9ad0626e720

file1.txt

# Set transient.
$ wp transient set sample_key "test data" 3600
Success: Transient added.

# Get transient.
$ wp transient get sample_key
test data

# Delete transient.
$ wp transient delete sample_key
Success: Transient deleted.

# Delete expired transients.
$ wp transient delete --expired
Success: 12 expired transients deleted from the database.

# Delete all transients.
$ wp transient delete --all
Success: 14 transients deleted from the database.

transient_sample.php

<?php
// Transient データを取得する
if ( WP_DEBUG or false === ( $value = get_transient( 'sample_key' ) ) ) {
    // Transient が存在しない場合 or デバッグモードのときにこの部分のコードが実行
    $value = ... // ここで $value の値を設定し直す
    // $value を Transient へ保存。12時間後に無効にする。
    set_transient( 'sample_key', $value, 12 * HOUR_IN_SECONDS );
}
echo $value;