Resource Meta options¶
Meta options are flags that can be applied to a resource to affect it’s behaviour or how it is dealt with via Odin tools.
Give your resource metadata by using an inner class Meta
, eg:
class Book(odin.Resource):
class Meta:
name_space = "library"
verbose_name_plural = "Books"
title = odin.StringField()
Resource metadata is “anything that’s not a field”, module_name and human-readable plural names (verbose_name and verbose_name_plural). None are required, and adding class Meta to a resource is completely optional.
Meta Options¶
name
- Override the name of a resource. This is the codecs when serialising/de-serialising as a name to represent the resource. The default name is the name of the class used to define the resource.
name_space
- The name space is an optional string value that is used to group a set of common resources. Typically a namespace should be in the form of dot-atoms eg: university.library or org.poweredbypenguins. The default is no namespace.
verbose_name
- A long version of the name for used when displaying a resource or in generated
documentation. The default verbose_name is a name attribute that has been
converted to lower case and spaces put before each upper case character
eg:
LibraryBook
-> “library book” verbose_name_plural
- A pluralised version of the verbose_name. The default is to use the verbose name and append an ‘s’ character. In the case of many words this does not work correctly so this attribute allows for the default behaviour to be overridden.
abstract
- Marks the current resource as an abstract resource. See the section
Abstract base classes for more detail of the abstract attribute. The default
value for abstract is
False
. doc_group
- A grouping for documentation purposes. This is purely optional but is useful for
grouping common elements together. The default value for doc_group is
None
. type_field
- The field used to identify the object type during serialisation/de-serialisation.
This defaults to the
$
character. key_field_name
- Used by external libraries like
baldr
for identifying what field is used as the key field to uniquely identify a resource instance (a good example would be an ID field). key_field_names
- Similar to the
key_field_name
but for defining multi-part keys. field_name_format
Provide a function that can be used to format field names. Field names are used to identify values when a resource serialised/deserialised.
For example to use camelCase names specify the following option:
from odin.utils import snake_to_camel class MyResource(Resource): class Meta: field_name_format = snake_to_camel
field_sorting
Used to customise how fields are sorted (primarily affects the order fields will be exported during serialisation) during inheritance. The default behaviour is to sort fields in the child resource before appending the fields from the parent resource(s).
Settings this option to
True
will cause field sorting to happen after all of the fields have been attached using the default sort method. The default method sorts the fields by the order they are defined.Supplying a callable allows for customisation of the field sorting eg sort by name:
def sort_by_name(fields): return sorted(fields, key=lambda f: f.name) class MyResource(Resource): class Meta: field_sorting = sort_by_name
user_data
Additional data that can be added to metadata. This can be used to provide additional parameters beyond those supported by odin for a custom application use-case.
For example:
class MyResource(Resource): class Meta: user_data = { "custom": "my-custom-value", }