PHP Form Validation

The HTML form we will be working at in these chapters, contains various input fields: required and optional text fields, radio buttons, and a submit button:

• PHP Form Validation

Example

The validation rules for the form above are as follows:

Field	Validation Rules
Name	Required. + Must only contain letters and whitespace
E-mail	Required. + Must contain a valid email address (with @ and .)
Website	Optional. If present, it must contain a valid URL
Comment	Optional. Multi-line input field (textarea)
Gender	Required. Must select one

• Text Fields

The name, email, and website fields are text input elements, and the comment field is a textarea. The HTML code looks like this:


Name: <input type="text" name="name">
E-mail: <input type="text" name="email">
Website: <input type="text" name="website">
Comment: <textarea name="comment" rows="5" cols="40"></textarea>

• Radio Buttons

The gender fields are radio buttons and the HTML code looks like this:


Gender:
<input type="radio" name="gender" value="female">Female

<input type="radio" name="gender" value="male">Male

<input type="radio" name="gender" value="other">Other

• The Form Element

The HTML code of the form looks like this:


<form method="post" action="<?php echo htmlspecialchars($_SERVER["PHP_SELF"]);?>">

When the form is submitted, the form data is sent with method="post".