SENDING FORM DATA

Client/server architecture

An HTML form on a web page is nothing more than a convenient user-friendly way to configure an HTTP request to send data to a server. This enables the user to provide information to be delivered in the HTTP request.

On the client side: defining how to send the data The <form> element defines how the data will be sent. All of its attributes are designed to let you configure the request to be sent when a user hits a submit button. The two most important attributes are action and method.

The action attribute

The action attribute defines where the data gets sent. Its value must be a valid relative or absolute URL. If this attribute isn’t provided, the data will be sent to the URL of the page containing the form — the current page.

The method attribute

The method attribute defines how data is sent. The HTTP protocol provides several ways to perform a request; HTML form data can be transmitted via a number of different methods, the most common being the GET method and the POST method

The GET method

The GET method is the method used by the browser to ask the server to send back a given resource: “Hey server, I want to get this resource.” In this case, the browser sends an empty body. Because the body is empty, if a form is sent using this method the data sent to the server is appended to the URL.

The POST method

The POST method is a little different. It’s the method the browser uses to talk to the server when asking for a response that takes into account the data provided in the body of the HTTP request: “Hey server, take a look at this data and send me back an appropriate result.” If a form is sent using this method, the data is appended to the body of the HTTP request.