Form Validation Using JavaScript's Constraint Validation API

Form validation is one of the primary reasons to use client-side JavaScript. It can prevent user entry errors before your app attempts to submit data to the server. But… client-side validation is not a substitute for server-side validation! Always check incoming user data on the server. Not every request will come from a browser nor will every browser run validation code. Client-side validation is

[efcl]

FormのHTML要素、CSS、JavaScriptでのバリデーションについての記事。

[jay-es]

前半はHTML フォームの type や属性、CSS 擬似クラスの説明。後半から Constraint Validation API の説明、カスタムバリデーションなど