Webformularer

Webformularer, or web forms, are structured collections of form controls embedded in web pages that enable users to submit information to a web server or an API. They are used for contact requests, registrations, orders, surveys, and many other interactive tasks on the internet. A typical webformularer consists of a form element with a name attribute, one or more input controls (such as text, email, password, number, date), select menus, textareas, checkboxes, and radio buttons, together with labels and a submit button. The organization of fields, the type of data expected, and any validation constraints are declared through attributes on the controls and the form element.

Submission of a webformularer sends the collected data to a server endpoint specified by the form's action attribute using a method attribute value of GET or POST. GET appends data to the URL and is suited for idempotent queries, while POST sends data in the request body and is preferred for sensitive or large payloads. Webformularer can also be processed asynchronously via JavaScript using techniques such as the fetch API or XMLHttpRequest, enabling dynamic feedback without full page reloads.

Accessibility and usability are important: every input should be associated with a readable label, focus order should be logical, and controls should work with keyboard navigation. HTML5 introduces built‑in validation features (required, type, pattern, min, max) and new input types that simplify client‑side checks, though server‑side validation remains essential for security.

Security and privacy considerations include using HTTPS, protecting against CSRF with tokens, sanitizing and validating input on the server, and minimizing data collection. Data encoding for form submissions can be application/x-www-form-urlencoded or multipart/form-data, the latter necessary for file uploads.