Add improvements to the tutorial section

docs/source/tutorial/basics.rst

@@ -7,8 +7,7 @@ Quickstart
 This page introduces to the basics of Oblate.
 
 Oblate's main components is the :class:`oblate.Schema` class which is used to define schemas
-that can be used for validating data. A schema is essentially a data class. Start by defining
-your own schema::
+that can be used for validating data. Start by defining your own schema::
 
     from oblate import fields
     import oblate
@@ -18,8 +17,8 @@ your own schema::
         username = fields.String()
         is_employee = fields.Boolean(default=False)
 
-Each schema has fields which are essentially just the attributes of a schema. ``oblate.fields`` provides
-various pre-defined fields that support standard validation rules.
+Each schema has fields which are essentially just the attributes of a schema. ``oblate.fields``
+provides various pre-defined commonly used fields that support standard validation rules.
 
 Now we can use raw data to initialize our schema::
 
@@ -30,5 +29,13 @@ Now we can use raw data to initialize our schema::
     print(emily.username, "is employee?", emily.is_employee)  # Emily is employee? True
 
 Each field of the schema is accessed exactly the same way as normal attributes of a class are
-accessed. Note how the ``default`` argument was used for defaulting ``is_employee`` value. There
-are many other similar options that allow easy customization of each field.
+accessed.
+
+Note how the ``default`` argument was used for assigning default ``is_employee`` value
+in case it is not provided in the data. There are many other similar options that
+allow easy customization of each field. Some of the commonly used ones are:
+
+- :ref:`guide-fields-optional-fields-and-defaults`
+- :ref:`guide-fields-noneable-nullable-fields`
+- :ref:`Strict/Non-Strict Fields <guide-fields-strict-mode>`
+- :ref:`guide-fields-frozen-fields`

docs/source/tutorial/errors.rst

@@ -45,4 +45,4 @@ Here's the result::
 
 .. TODO: Reference error customization tutorial here
 
-This "raw format" is fully customizable to suit any use case.
+This "raw format" is fully :ref:`customizable <guide-errors-raw-error-formatting>` to suit any use case.

docs/source/tutorial/validators.rst

@@ -9,6 +9,9 @@ validation features, also provides the ability of writing custom validators.
 
 This is done using the :func:`validate.field` function::
 
+    import oblate
+    from oblate import validate, fields
+
     class User(oblate.Schema):
         id = fields.Integer()
         username = fields.String()
@@ -34,3 +37,24 @@ causes the following error::
     └── In field username:
         └── This field is required.
 
+Pre-built Validators
+--------------------
+
+Some validators that are commonly used in various cases are preshipped by Oblate so you
+don't have to implement such validations yourself. These validators are provided by the
+``oblate.validate`` module.
+
+For example, the range validator that we implemented above can be replaced with the one
+already provided by the library::
+
+    class User(oblate.Schema):
+        id = fields.Integer(validators=[validate.Range(1000, 9999)])
+        username = fields.String()
+        is_employee = fields.Boolean(default=False)
+
+The ``validators`` parameter takes a sequence of :class:`validate.Validator` objects.
+
+It is recommended to use the pre-defined validators whenever possible as they are
+tailored to be robust and flexible to suit most use cases.
+
+These validators are documented in :ref:`Validators API Reference <api-validators>`.