The validation class comes with a lot of pre-built functions to validate data, some of which use the validation filters ( https://www.php.net/manual/en/filter.filters.validate.php ) while others are bespoke

Validation filters

• BOOLEAN - Allows 1, true, on, yes, 0, false, off and no
• DOMAIN - Validates whether the domain name label lengths are valid.
• EMAIL - Validates whether the value is a valid e-mail address.
• FLOAT - Validates value as float
• INT - Validates value as integer
• IP - Validates value as IP address
• MAC - Validates value as MAC address
• REGEXP - Validates value against regexp
• URL - Validates value as URL

Bespoke validation

• money - Limits value to 2 decimal places and does not allow e numbers.
• postcode - Validates UK Postcodes
• tel - Validates Telephone number
• date - Validates date
• date-time - Validates datetime
• month - Makes sure that the input complies with the format YYYY-MM then does a further check to make sure the month is >0 and <13
• time - Validates time.
• week - makes sure that the input complies with YYYY-W week. Additional check that the week >0 and <54
• unique - Only characters within the unique set of characters are allowed
• captcha - This validation occurs automatically if you use a capcha element in your form

Validation is contained within a class so that if an extra validation is required then the class can be extended

In addition to this validation, the class also checks if a field is required

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