27 lines
1.5 KiB
ReStructuredText
27 lines
1.5 KiB
ReStructuredText
|
A word on validation
|
|||
|
|
====================
|
|||
|
|
|
|||
|
|
It’s generally considered a good idea to centralise your data validation
|
|||
|
|
in a single place, and a good place to do this is inside your model
|
|||
|
|
classes. This is preferable to handling validation alongside form
|
|||
|
|
handling code, for example. Placing validation code inside models means
|
|||
|
|
that if you extend your application in the future to update your model
|
|||
|
|
via an alternative route (say a REST API rather than a form) you can
|
|||
|
|
re-use the same validation code.
|
|||
|
|
|
|||
|
|
Despite this, Paris doesn’t provide any built-in support for validation.
|
|||
|
|
This is because validation is potentially quite complex, and often very
|
|||
|
|
application-specific. Paris is deliberately quite ignorant about your
|
|||
|
|
actual data - it simply executes queries, and gives you the
|
|||
|
|
responsibility of making sure the data inside your models is valid and
|
|||
|
|
correct. Adding a full validation framework to Paris would probably
|
|||
|
|
require more code than Paris itself!
|
|||
|
|
|
|||
|
|
However, there are several simple ways that you could add validation to
|
|||
|
|
your models without any help from Paris. You could override the
|
|||
|
|
``save()`` method, check the data is valid, and return ``false`` on
|
|||
|
|
failure, or call ``parent::save()`` on success. You could create your
|
|||
|
|
own subclass of the ``Model`` base class and add your own generic
|
|||
|
|
validation methods. Or you could write your own external validation
|
|||
|
|
framework which you pass model instances to for checking. Choose
|
|||
|
|
whichever approach is most suitable for your own requirements.
|