Class Validator

source code

object --+
         |
        Validator

Known Subclasses:

• CLEANUP
• , IS_MATCH
• , IS_DATE
• , IS_DATETIME
• , IS_DECIMAL_IN_RANGE
• , IS_EMAIL
• , IS_EMPTY_OR
• , IS_EXPR
• , IS_FLOAT_IN_RANGE
• , IS_GENERIC_URL
• , IS_HTTP_URL
• , IS_IMAGE
• , IS_INT_IN_RANGE
• , IS_IN_DB
• , IS_IN_SET
• , IS_IPV4
• , IS_LENGTH
• , IS_LIST_OF
• , IS_LOWER
• , IS_NOT_EMPTY
• , IS_NOT_IN_DB
• , IS_SLUG
• , IS_TIME
• , IS_UPLOAD_FILENAME
• , IS_UPPER
• , IS_URL

Root for all validators, mainly for documentation purposes.

Validators are classes used to validate input fields (including forms generated from database tables).

Here is an example of using a validator with a FORM:

   INPUT(_name='a', requires=IS_INT_IN_RANGE(0, 10))

Here is an example of how to require a validator for a table field:

   db.define_table('person', SQLField('name'))
   db.person.name.requires=IS_NOT_EMPTY()

Validators are always assigned using the requires attribute of a field. A field can have a single validator or multiple validators. Multiple validators are made part of a list:

   db.person.name.requires=[IS_NOT_EMPTY(), IS_NOT_IN_DB(db, 'person.id')]

Validators are called by the function accepts on a FORM or other HTML helper object that contains a form. They are always called in the order in which they are listed.

Built-in validators have constructors that take the optional argument error message which allows you to change the default error message. Here is an example of a validator on a database table:

   db.person.name.requires=IS_NOT_EMPTY(error_message=T('fill this'))

where we have used the translation operator T to allow for internationalization.

Notice that default error messages are not translated.