Returns true if string contains only alphanumeric characters. Punctuation, whitespace, and another other special characters will cause a false.
secret_phrase: abc123even_more_secret_phrase: abc123!@#{{ if secret_phrase | is_alphanumeric }}{{ if even_more_secret_phrase | is_alphanumeric }}@if (Statamic::modify($secret_phrase)->isAlphanumeric()->fetch()) @endif@if (Statamic::modify($even_more_secret_phrase)->isAlphanumeric()->fetch()) @endiftruefalse
