straint violation on a form, call <code>server_side_constraint_violation</code>:</p><div class="language-ruby vp-adaptive-theme"><button title="Copy Code" class="copy"></button><span class="lang">ruby</span><pre class="shiki shiki-themes github-light github-dark vp-code" tabindex="0"><code><span class="line"><span style="--shiki-light:#24292E;--shiki-dark:#E1E4E8;">form.</span><span style="--shiki-light:#6F42C1;--shiki-dark:#B392F0;">server_side_constraint_violation</span><span style="--shiki-light:#24292E;