pip_services3_commons.reflect.ObjectReader module

pip_services3_commons.reflect.ObjectReader

Object reader implementation

copyright: Conceptual Vision Consulting LLC 2018-2019, see AUTHORS for more details.
license: MIT, see LICENSE for more details.

class pip_services3_commons.reflect.ObjectReader.ObjectReader

Bases: object

Helper class to perform property introspection and dynamic reading.

In contrast to PropertyReflector which only introspects regular objects, this ObjectReader is also able to handle maps and arrays.

For maps properties are key-pairs identified by string keys, For arrays properties are elements identified by integer index.

This class has symmetric implementation across all languages supported by Pip.Services toolkit and used to support dynamic data processing.

Because all languages have different casing and case sensitivity __rules, this ObjectReader treats all property names as case insensitive.

Example:

myObj = MyObject()

properties = ObjectReader.get_property_names()

ObjectReader.has_property(myObj, "myProperty")
args = PropertyReflector.get_property(myObj, "myProperty")

myMap = { key1: 123, key2: "ABC" }
ObjectReader.has_property(myMap, "key1")
args = ObjectReader.get_property(myMap, "key1")

myArray = [1, 2, 3]
ObjectReader.has_property(myArrat, "0")
args = ObjectReader.get_property(myArray, "0")

static get_properties(obj: Any) → Any

Get values of all properties in specified object and returns them as a map.

The object can be a user defined object, map or array. Returned properties correspondently are object properties, map key-pairs or array elements with their indexes.

Parameters: obj – an object to get properties from.
Returns: a map, containing the names of the object’s properties and their values.

static get_property(obj: Any, name: str) → Any

Gets args of object property specified by its name.

The object can be a user defined object, map or array. The property name correspondently must be object property, map key or array index.

Parameters

obj – an object to read property from.
name – a name of the property to get.

Returns

the property args or null if property doesn’t exist or introspection failed.

static get_property_names(obj: Any) → List[str]

Gets names of all properties implemented in specified object.

The object can be a user defined object, map or array. Returned property name correspondently are object properties, map keys or array indexes.

Parameters: obj – an object to introspect.
Returns: a list with property names.

static get_value(obj: Any) → Any

Gets a real object args. If object is a wrapper, it unwraps the args behind it. Otherwise it returns the same object args.

Parameters: obj – an object to unwrap.
Returns: an actual (unwrapped) object args.

static has_property(obj: Any, name: str) → bool 

Checks if object has a property with specified name.

The object can be a user defined object, map or array. The property name correspondently must be object property, map key or array index.

Parameters

obj – an object to introspect.
name – a name of the property to check.

Returns

true if the object has the property and false if it doesn’t.